Information processing device, simulation method, and simulation program

Abstract

In order to improve the convenience of simulation based on the results of causal analysis, an information processing device (1) comprises: an element extraction unit (11) that, in a simulation that changes the value of an objective variable to a target value, extracts, for each mode of the simulation, an element corresponding to the mode from among the plurality of elements causally connected to the objective variable; and a display control unit (12) that displays the extracted elements for each mode as target elements of which values are to be changed in order to change the objective variable to the target value.

Description

Information processing device, simulation method, and simulation program

[0001] The present invention relates to an information processing device or the like that performs processing related to causal analysis.

[0002] A method known as causal analysis is known for discovering causal relationships between multiple elements based on data relating to each of those elements. For example, Patent Literature 1 listed below describes constructing a directed acyclic graph that represents the relationships between multiple variables and a target outcome. The same document also describes using the constructed directed acyclic graph to analyze whether sufficient causal evidence exists to identify a causal relationship between a variable of interest and the target outcome.

[0003] Japanese Patent Application Laid-Open No. 2019-194849

[0004] The above-described conventional techniques leave room for improvement in terms of convenience when performing simulations based on the results of causal analysis. Specifically, if causal relationships between elements are revealed through causal analysis, it is possible to simulate what values ​​other elements need to have in order to achieve a target value for a certain element. However, when there are a large number of elements causally connected to the element whose value is to be set as a target value, it is cumbersome to determine a policy for selecting elements whose values ​​are to be changed and to extract elements according to that policy. Furthermore, such tasks are difficult for those unfamiliar with causal analysis.

[0005] An object of one aspect of the present invention is to provide an information processing device or the like that can improve the convenience of simulations based on the results of causal analysis.

[0006] An information processing device according to one aspect of the present invention comprises an element extraction means for extracting, for each mode of the simulation, one or more elements corresponding to a mode of the simulation from among a plurality of elements that are causally linked to the objective variable, in a simulation in which the value of one of the elements, an objective variable, is changed to a target value based on the results of a causal analysis of the plurality of elements, and a display control means for displaying, for each mode, the extracted elements as target elements whose values ​​should be changed in order to change the objective variable to the target value.

[0007] A simulation method according to one aspect of the present invention includes, in a simulation in which at least one processor changes the value of a target variable, which is one of a plurality of elements, to a target value based on the results of a causal analysis of the plurality of elements, extracting one or more elements corresponding to each mode of the simulation from among the plurality of elements that are causally connected to the target variable, and displaying the extracted elements for each mode as target elements whose values ​​should be changed in order to change the target variable to the target value.

[0008] A simulation program according to one aspect of the present invention causes a computer to function as: an element extraction means for extracting, for each mode of a simulation, one or more elements corresponding to a mode of the simulation from among a plurality of elements that are causally linked to a target variable, in a simulation in which the value of the target variable, which is one of the elements, is changed to a target value based on the results of a causal analysis of the plurality of elements; and a display control means for displaying, for each mode, the extracted elements as target elements whose values ​​should be changed in order to change the target variable to the target value.

[0009] According to one aspect of the present invention, it is possible to improve the convenience of simulations based on the results of causal analysis.

[0010] FIG. 1 is a block diagram showing the configuration of an information processing device according to exemplary embodiment 1 of the present invention. FIG. 2 is a flow diagram showing the flow of a simulation method according to exemplary embodiment 1 of the present invention. FIG. 3 is a block diagram showing the configuration of an information processing device according to exemplary embodiment 2 of the present invention. FIG. 4 is a diagram showing an example of a display screen displayed during a simulation. FIG. 5 is a diagram showing an example of an image for accepting designation of a target element. FIG. 6 is a diagram showing an example of a display screen when adding a target element. FIG. 7 is a flow diagram showing the flow of a simulation method according to exemplary embodiment 2 of the present invention. FIG. 8 is a diagram showing an example of a computer that executes instructions of a program that is software that realizes each function of each device according to each exemplary embodiment of the present invention.

[0011] [First Exemplary Embodiment] A first exemplary embodiment of the present invention will be described in detail with reference to the drawings. This exemplary embodiment is a basic form of the exemplary embodiments described below.

[0012] (Configuration of Information Processing Device) The configuration of an information processing device 1 according to this exemplary embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing the configuration of the information processing device 1. As shown in the figure, the information processing device 1 includes an element extraction unit 11 and a display control unit 12.

[0013] In a simulation in which the value of a target variable, which is one of the elements, is changed to a target value based on the results of a causal analysis of multiple elements, the element extraction unit 11 extracts one or more elements corresponding to each mode of the simulation from among multiple elements that are causally linked to the target variable.

[0014] The display control unit 12 displays the elements extracted by the element extraction unit 11 for each mode as target elements whose values ​​should be changed in order to change the objective variable to the target value.

[0015] As described above, the information processing device 1 according to this exemplary embodiment is configured to include an element extraction unit 11 that extracts, for each simulation mode, one or more elements from among the elements that are causally connected to the objective variable in a simulation in which the value of the objective variable, which is one of the elements, is changed to a target value based on the results of a causal analysis of the elements, and a display control unit 12 that displays, for each mode, the elements extracted by the element extraction unit 11 as target elements whose values ​​should be changed in order to change the objective variable to the target value. Therefore, the information processing device 1 according to this exemplary embodiment has the effect of improving the convenience of the simulation.

[0016] (Simulation Program) The functions of the information processing device 1 described above can also be realized by a program. The simulation program according to this exemplary embodiment is configured to cause a computer to function as: an element extraction unit that extracts, for each simulation mode, one or more elements from among a plurality of elements causally connected to the objective variable in a simulation in which the value of the objective variable, one of the elements, is changed to a target value based on the results of a causal analysis of the plurality of elements; and a display control unit that displays, for each mode, the elements extracted by the element extraction unit as target elements whose values ​​should be changed to change the objective variable to the target value. Therefore, the simulation program according to this exemplary embodiment has the effect of improving the convenience of the simulation.

[0017] (Flow of Simulation Method) The flow of the simulation method according to this exemplary embodiment will be described with reference to Fig. 2. Fig. 2 is a flow diagram showing the flow of the simulation method. Note that the execution entity of each step in this simulation method may be a processor provided in the information processing device 1, or a processor provided in another device, or each step may be executed by a processor provided in a different device.

[0018] In S11, at least one processor performs a simulation in which the value of a target variable, which is one of the elements, is changed to a target value based on the results of a causal analysis of multiple elements, and extracts one or more elements corresponding to each mode of the simulation from among the multiple elements that are causally linked to the target variable.

[0019] In S12, at least one processor displays the elements extracted in S11 for each mode as target elements whose values ​​should be changed in order to change the objective variable to a target value.

[0020] As described above, the simulation method according to this exemplary embodiment includes a configuration in which, in a simulation in which at least one processor changes the value of a response variable, which is one of a plurality of elements, to a target value based on the results of a causal analysis of the plurality of elements, the simulation method includes the steps of: extracting, for each simulation mode, one or more elements from among the plurality of elements that are causally connected to the response variable; and displaying, for each mode, the extracted elements as target elements whose values ​​should be changed in order to change the response variable to the target value. Therefore, the simulation method according to this exemplary embodiment has the effect of improving the convenience of the simulation.

[0021] [Exemplary Embodiment 2] (Configuration of Information Processing Device) The configuration of an information processing device 2 according to this exemplary embodiment will be described with reference to FIG. 3. FIG. 3 is a block diagram showing the configuration of the information processing device 2. As shown in the figure, the information processing device 2 includes a control unit 20 that controls each unit of the information processing device 2, and a storage unit 21 that stores various data used by the information processing device 2. The information processing device 2 also includes a communication unit 22 that enables the information processing device 2 to communicate with other devices, an input unit 23 that accepts various data input to the information processing device 2, and a display unit 24 that enables the information processing device 2 to display and output various data. Note that each of the components from the storage unit 21 to the display unit 24 may be built into the information processing device 2 or may be an external device attached to the information processing device 2.

[0022] The control unit 20 also includes a reception unit 201, a causal analysis unit 202, an element extraction unit 203, a change index calculation unit 204, a path coefficient calculation unit 205, a condition satisfaction determination unit 206, an element determination unit 207, a display control unit 208, and a simulation execution unit 209.

[0023] The reception unit 201 receives various user specifications related to the simulation. For example, the reception unit 201 receives a specification of an element to be used as a response variable in the simulation from among multiple elements causally analyzed by the causal analysis unit 202, and a specification of a target value for the response variable. The term "element" will be explained in the next paragraph.

[0024] The causal analysis unit 202 performs a causal analysis on a plurality of given elements to identify the causal structure and causal relationships between those elements. The elements to be subjected to the causal analysis are not particularly limited. For example, the elements to be subjected to the causal analysis may be each question item in a questionnaire and the answers to those questions, or the elements to be subjected to the causal analysis may be the behavior and its results shown in the behavioral history information of a subject or a group of subjects. Furthermore, the data format of each element may or may not be standardized. The causal analysis unit 202 may perform the causal analysis by applying a known causal inference or causal search method according to the target elements, etc.

[0025] In the following, an example will be described in which each element is a variable related to a certain event. For example, when performing a causal analysis on various events related to the sale of a product, a variable related to the event of a product being purchased (e.g., a numerical value indicating the number of products purchased or the sales price) can be an element. Also, a variable indicating the price of the product, which is related to the above event, can be an element.

[0026] By performing causal analysis, it becomes possible to predict how one of the variables related to such causal relationships will change when the other variable is changed. For example, in the above example, it is possible to predict the number of units sold of a product when the unit price of the product is reduced by 10%, or conversely, to predict how much the unit price of the product needs to be reduced to bring the number of units sold to above a threshold. In other words, it is possible to use a certain variable as an explanatory variable and another variable related to that variable by a causal relationship as a target variable, and to identify the relationship between these variables.

[0027] It should be noted that the information processing device 2 does not necessarily have to include the causal analysis unit 202. If the information processing device 2 does not include the causal analysis unit 202, it is sufficient for the information processing device 2 to acquire the results of the causal analysis performed in another device via the communication unit 22 or the input unit 23.

[0028] The element extraction unit 203 extracts one or more elements corresponding to each simulation mode from among a plurality of elements that are causally connected to the objective variable in the simulation performed by the simulation execution unit 209. The elements extracted by the element extraction unit 203 become explanatory variables in the simulation.

[0029] The simulation mode can also be referred to as the style of the simulation or the simulation policy. The simulation mode may be predetermined, or the user may be able to set some or all of the modes. For example, a mode in which the number of explanatory variables used is limited to a predetermined number or less, or a mode in which at least one explanatory variable is extracted from each of multiple paths, may be set. In this way, each mode may have pre-set rules for determining the elements to be used as explanatory variables in that mode. The mode can also be said to specify the range of explanatory variables. Note that a "path" is a series of elements that has a target variable as its end element and includes one or more explanatory variable elements that are directly or indirectly causally connected to that element.

[0030] Furthermore, each element that has undergone causal analysis can be represented as a causal graph. In a causal graph, each element is represented as a "node," and the causal relationships between elements are represented as "edges" connecting the nodes. Nodes are further classified into RCVs (Root Cause Variables), which are the starting points of paths, targets, which are the end points of paths, and variables located between the RCVs and targets. Therefore, a "path" can also be expressed as a route consisting of one or more edges connecting an RCV and a target, or as a matrix of nodes from the RCVs to the targets connected by edges. Paths can also be classified into direct paths, which directly connect an RCV and a target, and indirect paths, which involve one or more variables between the RCV and the target.

[0031] The target, which is the end point of the path, is also called the objective variable, response variable, reaction variable, outcome variable, dependent variable, or non-explanatory variable. The RCV, which is the start point of the path, and the variables located between the RCV and the target are also called explanatory variables, predictor variables, or independent variables.

[0032] The change index calculation unit 204 calculates an index value indicating the degree of change in the dependent variable (which can also be called a target variable) when the value of each element that is causally linked to the dependent variable is changed, i.e., when the value of the explanatory variable is changed.

[0033] The index value indicating the degree of change may, for example, indicate the amount of change or the rate of change. For example, the change index calculation unit 204 may calculate the amount of change in the objective variable when the explanatory variable is increased by a predetermined amount (for example, 1) as the index value. This index value can be calculated by multiplying the amount of change in the explanatory variable by a path coefficient, which will be described later. Note that, when there are multiple paths, the index value can be calculated by summing up the products of the amount of change in the explanatory variable and each path coefficient. Similarly, it is also possible to calculate the rate of change in the objective variable when the explanatory variable is increased by a predetermined amount or a predetermined rate.

[0034] The index value may also indicate a change in a statistical quantity. For example, the change index calculation unit 204 may calculate the index value indicating a change in a statistical quantity of the dependent variable when the explanatory variable is increased by a predetermined amount (for example, 1). The statistical quantity may be, for example, a standard deviation. For example, the change index calculation unit 204 may calculate, as the index value, a ratio of the standard deviation of the dependent variable after the explanatory variable is changed to the standard deviation of the dependent variable before the explanatory variable is changed. Furthermore, the user may be able to specify the statistical quantity to be targeted.

[0035] For each element causally connected to the objective variable, the path coefficient calculation unit 205 calculates a path coefficient of a path connecting the element and the element set as the objective variable. The path coefficient is a coefficient calculated using the weight of each edge connecting each element subjected to the causal analysis. Specifically, for a direct path, the path coefficient calculation unit 205 calculates the weight of the edge constituting the path. For an indirect path, the path coefficient calculation unit 205 calculates the product of the weights of the multiple edges constituting the path. Note that the product of the edge weights is merely one example of a path coefficient, and path coefficients may be calculated using other methods. A path with a larger path coefficient value is more likely to be a useful path.

[0036] The condition satisfaction determination unit 206 determines whether or not each of the elements causally connected to the objective variable satisfies a predetermined condition. Any condition may be set, and the user may also be able to set the condition. For example, conditions may be set regarding the index value calculated by the change index calculation unit 204, the path coefficient calculated by the path coefficient calculation unit 205, etc. As a specific example, the condition satisfaction determination unit 206 may determine that an element whose index value is equal to or less than a predetermined threshold satisfies the condition, and that an element whose index value is less than the threshold does not satisfy the condition.

[0037] When the objective variable does not reach the target value in the simulation, the element determination unit 207 determines an element to be used as a target element from among elements causally connected to the objective variable, in place of or in addition to the target element applied in the simulation. Note that the target element is an element extracted by the element extraction unit 203.

[0038] The display control unit 208 displays, for each mode, the elements extracted by the element extraction unit 203 as target elements whose values ​​should be changed in order to change the objective variable to the target value. The display format may be any format that allows the user to recognize the mode and the corresponding target element. The display of the target element will be described later with a specific example in the section "Example of display screen during simulation."

[0039] The simulation execution unit 209 performs a simulation based on the results of the causal analysis of multiple elements performed by the causal analysis unit 202. Specifically, the simulation execution unit 209 calculates the value of each target element to bring the objective variable to a target value. In other words, the simulation execution unit 209 predicts how the value of the target element will change to change the objective variable to the target value.

[0040] (Example of display screen during simulation) Fig. 4 is a diagram showing an example of a display screen displayed during a simulation by the display control unit 208. The example display screen in Fig. 4 includes an area a1 for receiving input of simulation conditions, areas a2 and a3 for displaying the results of the simulation, and an area a4 for displaying a causal graph.

[0041] (Regarding Area a1) Area a1 displays an object a11 for receiving the specification of a response variable and an object a12 for receiving the specification of a target value. Area a1 also displays an object a13 for receiving the specification of candidate target elements, which are elements to be simulated, and an object a14 for receiving the specification of simulation conditions.

[0042] The user selects object all and specifies an element to be used as a response variable by performing an input operation via the input unit 23. For example, when object all is selected, the display control unit 208 may display a list of elements that can be used as a response variable among the elements that have been subjected to the causal analysis, and allow the user to specify an element to be used as a response variable from the displayed list. When the user specifies an element, a character string indicating the specified element ("livability" in the example of FIG. 4) is displayed on object all.

[0043] The object a12 is an object in which a slider that can be moved on a slider bar is arranged on the slider bar. The slider bar indicates the range in which the value of the objective variable can be changed, and the position of the slider indicates the target value. The user specifies the target value by moving the slider to a desired position through an input operation via the input unit 23. In the example of FIG. 4, the target value is specified as "4.0".

[0044] Furthermore, the user selects object a13 by performing an input operation via the input unit 23 and specifies a candidate for the target element. When the user specifies a candidate, a character string indicating the specified candidate (such as "childcare facility" or "park" in the example of FIG. 4) is displayed on object a13. At this time, the display control unit 208 may display a list of elements that can be used as candidates for the target element, i.e., elements that are causally connected to the objective variable, and allow the user to specify an element from among the conditions displayed in the list. This will be described later in the section "Regarding acceptance of candidate specification."

[0045] Object a14 includes object a141 for receiving the specification of an attribute of data used in the causal analysis, object a142 for receiving the specification of a symbol, and object a143 for receiving the specification of a numerical value. The user performs an input operation via input unit 23 to select object a141 to specify an attribute, select object a142 to specify a symbol, and select object a143 to specify a numerical value. The content specified by the user is displayed on objects a141 to a143. Specifically, "age," "≧," and "30" are displayed. In other words, the condition specified is that a simulation is to be performed based on data targeting people 30 years of age or older.

[0046] Here, if the simulation conditions are changed, the causal analysis unit 202 may perform the causal analysis again under the changed conditions. For example, if the age is specified as 30 years or older as in the example of Fig. 4, the causal analysis unit 202 may perform the causal analysis again using data for people 30 years or older (e.g., responses from survey respondents 30 years or older). Furthermore, the causal analysis unit 202 may update the values ​​of the variables to those according to the specified conditions without updating the causal relationships.

[0047] (Regarding Acceptance of Designation of Candidates) When the object a13 is selected, the display control unit 208 may display an image as shown in Fig. 5 to allow the user to designate a candidate for the target element. Fig. 5 is a diagram showing an example of an image for accepting the designation of a candidate for the target element.

[0048] 5 displays a list of character strings such as "childcare facility" that indicate each element that can be used as a target element. Elements that can be used as target elements are elements that are causally connected to the objective variable and can change depending on the specified objective variable.

[0049] Image b1 also displays check boxes corresponding to each character string. The user can designate the corresponding element as a candidate for the target element by checking the check box through an input operation via the input unit 23. In the example of FIG. 5, the candidate for the target element is designated by selecting the check box with the cursor Cu. The designated elements with checked check boxes are "childcare facility" and "park."

[0050] 5, a speech bubble b2 is displayed for "childcare facility," which is the element over which the cursor Cu is positioned. The speech bubble b2 displays information that will be used to determine whether or not to select "childcare facility" as a candidate for the target element. Specifically, the speech bubble b2 displays information such as the fact that the path coefficient of the path connecting "childcare facility" and the objective variable ("livability" in the example of FIG. 4) is "0.4" and the cost of changing the value of the element by a predetermined amount.

[0051] The "cost" mentioned above includes at least one of monetary cost, time cost, and human cost. The cost required to change the value of each element by a unit amount may be specified in advance. For example, if the amount of money, time, or number of people required to increase the value of each element by one point is specified in advance and stored in the storage unit 21, the display control unit 208 can display the cost value.

[0052] The path coefficients may be calculated by the path coefficient calculation unit 205. Note that the information used to determine whether or not to select an element as a candidate for the target element is not limited to these examples. For example, the index value calculated by the change index calculation unit 204, the determination result of the condition satisfaction determination unit 206, etc. may be displayed. The method of displaying this information is arbitrary and is not limited to the example shown in the figure.

[0053] The element extraction unit 203 extracts target elements for each simulation mode from the candidate target elements specified as described above. Note that it is not essential to specify candidate target elements. If candidate target elements are not specified, the element extraction unit 203 extracts target elements from each element that is causally connected to the objective variable.

[0054] As described above, the display control unit 208 may display, for each of a plurality of elements causally connected to the objective variable, at least one of an index value indicating the degree of change in the objective variable when the value of the element is changed, a path coefficient of a path connecting the element and the objective variable, and a cost for changing the value of the element by a predetermined amount. The receiving unit 201 may then receive a selection of a plurality of elements causally connected to the objective variable, and the element extraction unit 203 may extract, as target elements, one or more elements including the element selected by the receiving unit 201. This allows the user to select target elements taking into consideration the above-mentioned index values ​​and costs.

[0055] (Regarding Area a2) In the example of FIG. 4, target elements are extracted for each of the "balance mode" and "single conversion mode," and the simulation results for each of these modes are displayed in areas a2 and a3, respectively. The "balance mode" is a mode in which a simulation is performed by changing multiple target elements. In the "balance mode," the values ​​of each target element may be changed by a fixed ratio or amount, or may be changed by individual values ​​or ratios. The "single conversion mode" is a mode in which a simulation is performed using one target element (e.g., the target element with the highest intervention effect). The element extraction unit 203 extracts target elements corresponding to each mode according to the rules for each mode.

[0056] Note that the above-described "balanced mode" and "single conversion mode" are merely examples of "modes" in this exemplary embodiment, and the "modes" in this exemplary embodiment are not limited to these examples. For example, a mode in which a simulation is performed using the top n target elements (n is an integer) with the highest intervention effects may be applied.

[0057] In area a2 shown in FIG. 4, the character string "Balance Mode" indicating the simulation mode, the set target value, and information indicating the change in the objective variable are displayed. Specifically, it is shown that the simulation is to increase the value of the objective variable "livability" from 3.0 to 4.0 (a 33% increase). It is also possible to perform a simulation in which the values ​​of the objective variable and the explanatory variables are decreased.

[0058] Furthermore, area a2 displays character strings such as "ease of child-rearing" indicating each element extracted as a target element for the balance mode, and information indicating how to change the target elements to change the objective variable to the target value. Specifically, it shows that the objective variable can be changed to the target value by changing the target element "ease of child-rearing" from its current value of "3.1" to "4.5" (a 45% increase), by changing the target element "childcare facilities" from "2.5" to "4.3" (a 72% increase), and by changing the target element "parks" from "2.8" to "4.2" (a 50% increase).

[0059] In this way, the display control unit 208 may not only display the target elements for each mode, but also display information indicating how to change the values ​​of the target elements to change the objective variable to the target value. This provides the effect of allowing the user to recognize how to change the values ​​of the target elements to bring the objective variable to the target value, in addition to the effect achieved by the information processing device 1 according to the exemplary embodiment 1. Note that it is not essential to display the information indicating how to change the values ​​of the target elements; it is sufficient for the display control unit 208 to display at least the target elements for each mode.

[0060] (Regarding Area a3) Area a3 displays the character string "single conversion mode" indicating the simulation mode, and the set target value (4.0). In this example, the value of "livability" did not reach the target value, and the numerical value "-0.6" indicating that the result was 0.6 below the target value is displayed in association with the target value. Area a3 also displays information indicating a change in the objective variable. Specifically, it shows that the value of the objective variable "livability" has increased from 3.0 to 3.4, and that the rate of increase is 13%.

[0061] Furthermore, area a3 displays the character string "Ease of child-rearing," which indicates the element extracted as the target element in the single conversion mode, and information indicating how to change the target element to change the objective variable as described above (increase from 3.0 to 3.4). Specifically, it shows that the objective variable can be increased to 3.4 by changing the current value of the target element "Ease of child-rearing," which is 3.1, to its maximum value, 5.0 (a 61% increase).

[0062] In this way, the simulation execution unit 209 may calculate a value that brings the objective variable closest to the target value if the objective variable does not reach the target value by changing the value of the target element extracted by the element extraction unit 203. Note that, as will be described later in "Processing when the target value is not reached," if the target value is not reached, the simulation may be performed again by adding a target element.

[0063] (Regarding Area a4) Next, we will explain area a4 for displaying a causal graph. A causal graph is a graph in which multiple elements that have been subjected to causal analysis are represented by nodes, and the causal relationships between each element are indicated by directed edges (unidirectional arrows), and is also called a directed acyclic graph. The causal graph displayed in area a4 consists of seven nodes N1 to N7. Note that instead of a directed acyclic graph, a CPDAG (Completed Partially Directed Acyclic Graph) or an undirected graph may be displayed.

[0064] Displaying a causal graph allows the user to easily recognize the relationships between elements. For example, in the example of Figure 4, a directed edge extending from node N3 (childcare facilities) connects to node N2 (ease of raising children), and a directed edge extending from node N2 connects to node N1 (ease of living). This allows the user to recognize at a glance that "childcare facilities" affect "ease of raising children," and "ease of raising children" affects "ease of living."

[0065] In addition, in the causal graph shown in Figure 4, numerical values ​​are displayed in association with each node. These numerical values ​​indicate the values ​​of the variables (explanatory variables or target variables) of each node. For example, the numerical value "4.1" is associated with node N6 (waterside environment), which indicates that the value of the explanatory variable corresponding to node N6 is 4.1.

[0066] Furthermore, in this causal graph, nodes N2 to N4 are indicated by dashed circles, and node N1 is indicated by a thick circle. The dashed circle indicates that the element corresponding to the node is the target element extracted by the element extraction unit 203, and the thick circle indicates that the variable corresponding to the node is set as the target variable of the simulation.

[0067] In this causal graph, the elements indicated by dashed circles are those extracted as target elements for the balance mode. To indicate this, the display control unit 208 displays the frame line surrounding the area a2 corresponding to the balance mode in bold. The user may be allowed to select which mode's target elements are to be displayed on the causal graph.

[0068] In this way, the display control unit 208 may display, on the causal graph, a node corresponding to the target element extracted by the element extraction unit 203 so as to be distinguishable from other nodes, thereby allowing the user to recognize the position of the target element in the entire causal graph and the relationship between the target elements.

[0069] Nodes N1 to N4 show the results of the simulation. Specifically, by increasing the value of "childcare facilities" from "2.5" to "4.3" and the value of "parks" from "2.8" to "4.2," the value of "ease of raising children," which is downstream of these factors, is increased from "3.1" to "4.5," and the "ease of living" can be increased from the current value of "3.0" to the target value of "4.0."

[0070] In this way, the display control unit 208 may display, on the causal graph, information indicating how to change the value of the target element to change the objective variable to the target value, thereby allowing the user to recognize how a change in the variable of a certain target element affects the objective variable.

[0071] The display manner of the target elements is not limited to the illustrated example, as long as it allows the user to recognize the mode and the corresponding target elements. For example, the display control unit 208 may display the target elements by displaying paths from the elements of the objective variable to the elements extracted by the element extraction unit 203. For example, in the case of the "balance mode" in FIG. 4, the display control unit 208 may display a path from node N3 to node N1 via node N2, and a path from node N4 to node N1 via node N2. Note that a branch may be treated as a single path, in which case a path consisting of node N1 to node N4 may be displayed.

[0072] (Processing When Target Value Is Not Reached) As described above, if the objective variable does not reach the target value by changing the value of the target element extracted by the element extraction unit 203, the target element may be added and the simulation may be performed again. This will be explained with reference to Fig. 6. Fig. 6 is a diagram showing an example of a display screen when a target element is added. More specifically, Fig. 6 shows another example of the display in area a3 of Fig. 4.

[0073] If the objective variable does not reach the target value by changing the value of the target element extracted by the element extraction unit 203, the display control unit 208 may display an object a31 for accepting addition or change of the target element, as shown in Fig. 6. In the example of Fig. 6, the target value is not reached in the single conversion mode, and the object a31 is displayed in the area a3 that is the display area for the simulation result of that mode.

[0074] Furthermore, when a user performs an operation to select object a31, the display control unit 208 may display a list of selectable elements and allow the user to specify a target element to be added. For example, the display control unit 208 may display image c1 shown in FIG. 6. Image c1 displays a character string (specifically, "ease of childcare") indicating the target element that was applied in the simulation that did not reach the target value, as well as a list of character strings such as "waterside environment" indicating target elements that can be added. Target elements that can be added are elements that are causally connected to the objective variable and that were not applied in the previous simulation.

[0075] Image c1 also displays check boxes corresponding to each character string. The user can specify target elements to be added by checking the check boxes through an input operation via the input unit 23. The user can also prevent a target element that was applied in the previous simulation from being applied by unchecking the check box corresponding to the target element. In the example of FIG. 6, the target element "ease of childcare" that was applied in the previous simulation remains as is, and "waterside environment" and "green area" are specified as target elements to be added.

[0076] When the target element is specified as described above, the element extraction unit 203 extracts the specified target element, and the simulation execution unit 209 performs a simulation again using the extracted target element, thereby specifying how to change the value of the target element in order to change the objective variable to the target value.

[0077] FIG. 6 also shows an example in which the results of the re-simulation are displayed in area a3. In the re-simulation, "waterside environment" and "green area" have been added as target elements. In this way, if the objective variable does not reach the target value by changing the value of the displayed target element, the display control unit 208 may display other elements that are causally linked to the objective variable ("waterside environment" and "green area" in the example of FIG. 6 ) instead of or in addition to the target element. This provides the effect of the information processing device 1 according to the first exemplary embodiment, as well as the effect of allowing the user to consider measures to bring the objective variable to the target value, including elements that were not displayed as target elements.

[0078] Furthermore, each target element is associated with information indicating how to change the value of that target element to change the objective variable to the target value. Specifically, it is shown that the objective variable can be changed to the target value by changing "ease of childcare" from "3.1" to "5.0," "waterside environment" from "4.1" to "4.5," and "green space area" from "2.5" to "3.5." This allows the user to recognize how to change the value of each target element to bring the objective variable to the target value.

[0079] In this example, the change in "ease of raising children" from "3.1" to "5.0" remains unchanged from the previous simulation. In other words, the simulation predicts how much the "waterside environment" and "green area" should be changed to further increase the "ease of raising children" by 0.6, after changing the "ease of raising children" from "3.1" to "5.0" to bring the "livability" to "3.4." Of course, the simulation execution unit 209 may also change the way in which the "ease of raising children" is changed. In this case, the simulation can be restarted from the beginning using the three target elements, "ease of raising children," "waterside environment," and "green area."

[0080] In addition, the element determination unit 207 may automatically determine a target element to replace a target element when the objective variable does not reach the target value, or a target element to be added when the objective variable does not reach the target value.

[0081] For example, the element determination unit 207 may determine an alternative target element or an additional target element from among elements (those causally connected to the objective variable) not extracted by the element extraction unit 203, based on at least one of the degree of change in the objective variable when the value of the element is changed, the path coefficient of the path connecting the element and the objective variable, and the cost for changing the value of the element by a predetermined amount. Furthermore, in the above determination, the element determination unit 207 may also take into consideration whether or not the condition satisfaction determination unit 206 has determined that the element satisfies the condition.

[0082] An element whose change in the objective variable when its value is changed is large is suitable as a target whose value is changed in order to bring the objective variable to a target value. Similarly, an element whose path coefficient of the path connecting the element and the objective variable is large or whose cost for changing its value by a predetermined amount is small is also suitable as a target whose value is changed in order to bring the objective variable to a target value. Therefore, by determining a replacement target element or an additional target element as described above, in addition to the effects achieved by the information processing device 1 according to the first exemplary embodiment, an effect of being able to present to the user an element whose value is suitable as a target whose value is changed can be obtained.

[0083] The degree of change in the objective variable when the value of an element is changed is indicated by an index value calculated by the change index calculation unit 204. The path coefficient is calculated by the path coefficient calculation unit 205. Therefore, by using these index values, the element determination unit 207 can determine, as an alternative target element or an additional target element, an element whose value changes greatly in the objective variable when changed, or an element whose path coefficient of the path connecting the element and the objective variable is large.

[0084] Furthermore, as described above, the cost for changing the value of each element by a predetermined amount may be specified in advance and stored in the storage unit 21, etc. By using such data, the element determination unit 207 can determine elements with a small cost for change as target elements to be substituted or added.

[0085] The object a31 for accepting addition or change of target elements may also display the modes in which the objective variables have reached the target values, allowing the user to customize the elements automatically extracted according to the mode and perform simulations.

[0086] Furthermore, the element determining unit 207 may rank the elements (those causally connected to the objective variable) that were not extracted by the element extracting unit 203. The ranking may be performed based on, for example, at least one of the degree of change in the objective variable when the value of the element is changed, the path coefficient of the path connecting the element and the objective variable, the cost for changing the value of the element by a predetermined amount, and whether or not the condition satisfaction determining unit 206 has determined that the condition is satisfied.

[0087] The ranking may be determined so that an element suitable as a target for changing a value is placed at the top. For example, the element determination unit 207 may rank the elements in descending order of the index value calculated by the change index calculation unit 204. The element determination unit 207 may also rank the elements based on multiple evaluation criteria. For example, the element determination unit 207 may assign points for each evaluation criterion, such as 10 points to the element with the lowest cost and 5 points to the element determined by the condition satisfaction determination unit 206 to satisfy the condition, and determine the display order in descending order of the total points.

[0088] By ranking the elements, the display control unit 208 can display each element according to the determined ranking and allow the user to select an alternative or additional target element from among the displayed elements.

[0089] (Flow of Simulation Method) The flow of the simulation method according to this exemplary embodiment will be described with reference to Fig. 7. Fig. 7 is a flow diagram showing the flow of the simulation method. Note that Fig. 7 shows processing in a state where the causal analysis by the causal analysis unit 202 has been completed and causal relationships between multiple elements have been identified.

[0090] In S21, the receiving unit 201 receives a designation of an element to be used as a response variable in the simulation from among the multiple elements that have been subjected to the causal analysis, and a designation of a target value for that response variable. Note that if the element to be used as the response variable has been determined in advance, for example, a flag may be set for that element so that it can be recognized as a response variable, and the reception of the designation of the response variable in S21 may be omitted. The receiving unit 201 may also receive a designation of the simulation conditions, a designation of elements to be candidate target elements, and a mode to be applied.

[0091] When accepting the designation of candidate elements for the target element, the processes of S26 to S29 may be performed for each of the elements that are causally connected to the objective variable. Then, the display control unit 208 may display the results of these processes as reference information for each element.

[0092] Furthermore, when accepting the designation of each element, the display control unit 208 may display a causal graph showing the relationships between each element that have been subjected to causal analysis, thereby allowing the user to designate an element after recognizing the causal relationships between each element.

[0093] In S22, the element extraction unit 203 extracts one or more elements corresponding to each simulation mode from among a plurality of elements that are causally connected to the objective variable. If a mode is specified in S21, the element extraction unit 203 extracts elements corresponding to the specified mode.

[0094] In S23, the display control unit 208 displays the elements extracted in S22 for each mode as target elements whose values ​​should be changed in order to change the objective variable to the target value.

[0095] In S24, the simulation execution unit 209 performs a simulation to calculate the value of each target element to bring the objective variable to the target value. The display control unit 208 then displays the calculated values. These values ​​indicate how to change the value of the target element to change the objective variable to the target value.

[0096] The displays in S23 and S24 may be performed together. Furthermore, the display control unit 208 may display the target element on the causal graph. In this case, the display control unit 208 may display the target element in a display mode that allows it to be distinguished from other elements. For example, the display control unit 208 may display the border of the node of the target element in a different manner from that of other nodes, as in the example of FIG. 4 . Furthermore, the display control unit 208 may also display, on the causal graph, information indicating how to change the value of the target element in order to change the objective variable to the target value.

[0097] In S25, the element determination unit 207 determines whether to add a target element. The criteria for determining whether to add a target element may be determined in advance. For example, the element determination unit 207 may determine to add a target element if the simulation performed in S24 includes a mode in which the objective variable does not reach the target value. Furthermore, for example, if the simulation performed in S24 includes a mode in which the objective variable does not reach the target value, the display control unit 208 may display an object for adding a target element (e.g., like object 31a shown in FIG. 6 ), and the element determination unit 207 may determine to add a target element when this object is selected.

[0098] In S26, the path coefficient calculation unit 205 calculates, for each element that is causally connected to the objective variable, the path coefficient of the path that connects that element with the element that is set as the objective variable. Note that the weight value used to calculate the path coefficient can be calculated using known causal inference or causal search techniques.

[0099] In S27, the change index calculation unit 204 calculates an index value indicating the degree of change in the dependent variable when the value of each element causally connected to the dependent variable, i.e., the value of the explanatory variable, is changed. The path coefficients calculated in S26 are used to calculate the index value.

[0100] In S28, the condition satisfaction determination unit 206 determines whether or not each of the elements causally connected to the objective variable satisfies a predetermined condition.

[0101] In S29, the element determining unit 207 identifies the cost for changing the value of each element that is causally connected to the objective variable by a predetermined amount.

[0102] In S30, the element determination unit 207 determines the target element to be added based on the results of S26 to S29, and the display control unit 208 displays the determined target element. Note that the element determination unit 207 does not necessarily need to use all of the results of S26 to S29. For example, the element determination unit 207 may determine the target element to be added based on some or all of the results of S26 to S29 in accordance with a user specification.

[0103] In S31, the simulation execution unit 209 adds the target element determined in S30 to the target element applied in the simulation in S24, and performs a simulation to calculate the value of each target element to bring the objective variable to a target value. The display control unit 208 then displays the calculated values. Note that the displays in S30 and S31 may be performed together. Similarly, it is also possible to determine a target element to be applied in place of the target element applied in the previous simulation, and perform a simulation using that target element. After S31 is completed, the process returns to S25.

[0104] In S30, the element determination unit 207 may rank the elements causally connected to the objective variable based on some or all of the results of S26 to S29. Then, the display control unit 208 may display a list of the elements causally connected to the objective variable in accordance with the above ranking, and allow the user to select a target element to be added.

[0105] [Modification] The execution entity of each process described in the above embodiment is arbitrary and is not limited to the above example. In other words, the functions of the information processing devices 1 and 2 can be realized by multiple devices (which can also be called processors) that can communicate with each other. For example, each process described in the flowcharts of Figures 2 and 7 can be shared and executed by multiple processors. In other words, the execution entity of the simulation method in the above embodiment may be one processor or multiple processors.

[0106] [Example of Software Implementation] Some or all of the functions of the information processing devices 1 and 2 may be implemented by hardware such as an integrated circuit (IC chip), or may be implemented by software.

[0107] In the latter case, the information processing devices 1 and 2 are realized, for example, by a computer that executes instructions of a program, which is software that realizes each function. An example of such a computer (hereinafter referred to as computer C) is shown in FIG. 8. The computer C includes at least one processor C1 and at least one memory C2. The memory C2 stores a program (simulation program) P for operating the computer C as the information processing device 1 or 2. In the computer C, the processor C1 reads and executes the program P from the memory C2, thereby realizing each function of the information processing device 1 or 2.

[0108] The processor C1 may be, for example, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a micro processing unit (MPU), a floating point number processing unit (FPU), a physics processing unit (PPU), a tensor processing unit (TPU), a quantum processor, a microcontroller, or a combination thereof. The memory C2 may be, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof.

[0109] The computer C may further include a RAM (Random Access Memory) for expanding the program P during execution and for temporarily storing various data. The computer C may also include a communication interface for transmitting and receiving data to and from other devices. The computer C may also include an input / output interface for connecting input / output devices such as a keyboard, a mouse, a display, and a printer.

[0110] The program P can also be recorded on a non-transitory, tangible recording medium M that can be read by the computer C. Such a recording medium M can be, for example, a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit. The computer C can acquire the program P via such a recording medium M. The program P can also be transmitted via a transmission medium. Such a transmission medium can be, for example, a communication network or broadcast waves. The computer C can also acquire the program P via such a transmission medium.

[0111] [Additional Note 1] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. For example, embodiments obtained by appropriately combining the technical means disclosed in the above-described embodiments are also included in the technical scope of the present invention.

[0112] [Additional Note 2] Part or all of the above-described embodiment can also be described as follows: However, the present invention is not limited to the following described aspects.

[0113] (Supplementary Note 1) In a simulation in which the value of a target variable, which is one of a plurality of elements, is changed to a target value based on the results of a causal analysis of the plurality of elements, an information processing device is provided, the information processing device comprising: an element extraction means for extracting, for each mode of the simulation, one or more elements corresponding to the mode from among a plurality of elements that are causally linked to the target variable; and a display control means for displaying, for each mode, the extracted elements as target elements whose values ​​should be changed in order to change the target variable to the target value.

[0114] (Supplementary Note 2) The information processing device according to Supplementary Note 1, wherein the display control means displays information indicating how to change the value of the target element in order to change the objective variable to the target value.

[0115] (Supplementary Note 3) The information processing device according to Supplementary Note 1 or 2, wherein the display control means, when changing the value of the displayed target element does not cause the objective variable to reach the target value, displays another element that is causally linked to the objective variable instead of or in addition to the target element.

[0116] (Supplementary Note 4) The information processing device according to Supplementary Note 3, further comprising an element determination means for determining the other element from among the elements not extracted by the element extraction means, based on at least one of the degree of change in the objective variable when the value of the element is changed, the path coefficient of the path connecting the element and the objective variable, and the cost for changing the value of the element by a predetermined amount.

[0117] (Supplementary Note 5) The information processing device according to any one of Supplementary Notes 1 to 4, wherein the display control means displays, for each of the plurality of elements causally connected to the objective variable, at least one of an index value indicating the degree of change in the objective variable when a value of the element is changed, a path coefficient of a path connecting the element and the objective variable, and a cost for changing the value of the element by a predetermined amount, and the information processing device further comprises a reception means for receiving a selection of the plurality of elements causally connected to the objective variable, and the element extraction means extracts one or more elements including the element whose selection has been received by the reception means.

[0118] (Supplementary Note 6) A simulation method comprising: in a simulation in which at least one processor changes the value of a response variable, which is one of a plurality of elements, to a target value based on the results of a causal analysis of the plurality of elements; extracting, for each mode of the simulation, one or more elements corresponding to the mode from among a plurality of elements that are causally connected to the response variable; and displaying, for each mode, the extracted elements as target elements whose values ​​should be changed in order to change the response variable to the target value.

[0119] (Supplementary Note 7) A simulation program that causes a computer to function as: an element extraction means that extracts, for each mode of a simulation, one or more elements corresponding to a mode from among a plurality of elements that are causally linked to a target variable, in a simulation in which the value of the target variable, which is one of the elements, is changed to a target value based on the results of a causal analysis of the plurality of elements; and a display control means that displays, for each mode, the extracted elements as target elements whose values ​​should be changed in order to change the target variable to the target value.

[0120] [Additional Note 3] Some or all of the above-described embodiments can also be expressed as follows: An information processing device including at least one processor, which executes, in a simulation in which a value of a response variable, which is one of a plurality of elements, is changed to a target value based on the result of a causal analysis of the plurality of elements, a process of extracting, for each mode of the simulation, one or more elements corresponding to the mode from among a plurality of elements that are causally connected to the response variable, and a process of displaying, for each mode, the extracted elements as target elements whose values ​​should be changed in order to change the response variable to the target value.

[0121] The information processing device may further include a memory that stores a program for causing the processor to execute the extraction process and the display process. The program may be recorded on a computer-readable, non-transitory, tangible recording medium.

[0122] REFERENCE SIGNS LIST 1 Information processing device 11 Element extraction unit (element extraction means) 12 Display control unit (display control means) 2 Information processing device 201 Reception unit (reception means) 203 Element extraction unit (element extraction means) 207 Element determination unit (element determination means) 208 Display control unit (display control means)

Claims

1. an element extraction means for extracting, for each mode of the simulation, one or more elements corresponding to the mode from among the plurality of elements causally connected to the objective variable in a simulation in which a value of the objective variable, which is one of the elements, is changed to a target value based on a result of a causal analysis of the plurality of elements; and a display control means for displaying the extracted elements for each of the modes as target elements whose values ​​should be changed in order to change the objective variable to the target value.

2. The information processing apparatus according to claim 1 , wherein the display control means displays information indicating how to change the value of the target element in order to change the objective variable to the target value.

3. 3. The information processing device according to claim 1, wherein the display control means, when changing the value of the displayed target element does not cause the objective variable to reach the target value, displays another element that is causally linked to the objective variable instead of or in addition to the target element.

4. 4. The information processing device according to claim 3, further comprising an element determination means for determining the other element from among the elements not extracted by the element extraction means, based on at least any of a degree of change in the objective variable when a value of the element is changed, a path coefficient of a path connecting the element and the objective variable, and a cost for changing the value of the element by a predetermined amount.

5. the display control means displays, for each of a plurality of the elements causally connected to the objective variable, at least one of an index value indicating a degree of change in the objective variable when a value of the element is changed, a path coefficient of a path connecting the element and the objective variable, and a cost for changing the value of the element by a predetermined amount; a receiving means for receiving a selection of a plurality of the elements that are causally connected to the objective variable, The information processing apparatus according to claim 1 , wherein the element extracting means extracts one or a plurality of elements including the element selected by the accepting means.

6. At least one processor In a simulation in which a value of a response variable, which is one of the elements, is changed to a target value based on a result of a causal analysis of the plurality of elements, one or more elements corresponding to each mode of the simulation are extracted from among the plurality of elements that are causally linked to the response variable; and displaying the extracted elements for each of the modes as target elements whose values ​​should be changed in order to change the objective variable to the target value.

7. Computer, an element extraction means for extracting, for each mode of the simulation, one or more elements corresponding to the mode from among a plurality of elements causally connected to the objective variable in a simulation in which a value of the objective variable, which is one of the elements, is changed to a target value based on a result of a causal analysis of the plurality of elements; a simulation program that functions as a display control means for displaying the extracted elements for each of the modes as target elements whose values ​​should be changed in order to change the objective variable to the target value;