DOM Tree Analysis for Web Page Navigation Region Identification

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Solution Overview

Problem

Conventional methods for identifying navigation regions in web pages using assistive technologies are inefficient due to reliance on visual content rendering, which does not match screen reader experiences, and often result in inaccurate calculations and computationally expensive machine-learning approaches.

Innovation Solution

A method based on document object model (DOM) analysis that identifies navigation regions by analyzing features such as interactive elements, content regions, and landmarks, representing them in a tree structure to determine link density, reading order, and main content roots, enabling effective region navigation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional approaches use page renderings to identify navigation regions, then visual layout information is available, but the content does not match what screen reader users experience and generation is difficult

Engineering Contradiction:
Improveaccuracy of navigation region identificationVSAvoiddifficulty of generating page renderings
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses the DOM tree as an intermediary representation between the web page content and the navigation region identification process. Instead of directly analyzing visual renderings or raw HTML, the system processes the DOM tree structure, which provides an abstracted view that matches screen reader experience while being computationally accessible. This intermediary representation resolves the contradiction by decoupling the analysis from both visual rendering complexity and raw content disorganization.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If machine-learning clustering algorithms are used to identify navigation regions, then comprehensive analysis is achieved, but computational cost is high and clustering results are difficult to label

Engineering Contradiction:
Improvecomprehensiveness of navigation region analysisVSAvoidcomputational expense
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces complex machine-learning clustering algorithms with a rule-based system that operates on DOM tree characteristics. Instead of using computationally expensive statistical clustering methods, the system applies deterministic rules based on DOM node properties, link density, and hierarchical structure. This substitution maintains comprehensive analysis capability while dramatically reducing computational overhead and eliminating the labeling difficulty associated with unsupervised clustering results.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Area of stationary object

If web browsers capture complete screenshots for analysis, then full web page content is available, but stitching screenshots together is complicated by scrolling-induced design changes

Engineering Contradiction:
Improvecoverage of web page contentVSAvoidcomplexity of stitching screenshots
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent creates a virtual copy of the web page content through the DOM tree structure, which represents the entire page hierarchy without requiring physical capture of visual content. This virtual representation allows complete content analysis while avoiding the stitching problem entirely, as the DOM tree naturally represents the full page structure including off-screen content through its hierarchical node relationships.

Inventive Principle:
Principle #26Copying

4Loss of information

If CSS computed values are used to calculate navigation regions, then rendering information is accessible, but calculations are inaccurate due to overflow and content filling issues

Engineering Contradiction:
Improveaccessibility of rendering informationVSAvoidaccuracy of region calculations
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The patent extracts the essential structural information from CSS computations by focusing on DOM node properties and hierarchical relationships rather than relying on computed rendering values. The system extracts link density, node depth, and hierarchical position from the DOM tree, separating the structural analysis from the rendering-specific calculations that cause accuracy problems with overflow and content filling.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS11194884B2Method for facilitating identification of navigation regions in a web page based on document object model analysis
Publication Date: 2021.12.07 ACCESSIBE LTD
  • US11194884B2 patent drawing
  • US11194884B2 patent drawing
  • US11194884B2 patent drawing

AI summary

A method for facilitating identification of navigation regions in a web page based on document object model (DOM) analysis is provided. In one embodiment, the method includes analyzing the web page for features. The features include at least one of: interactive elements, content regions, link region roots, or landmarks. The method also includes representing the features in a tree structure and analyzing the tree structure for a link density to identify non-main landmarks, a reading order, and main content roots. The method further includes enabling a region navigation for the web page based on the identified non-main landmarks, reading order, and main content roots.