WebAIM - Web Accessibility In Mind

Cognitive and Learning Disabilities Literature Review



The following is a summary of a literature review for WebAIM’s Phase I Steppingstones of Technology Innovation grant funded by the Office of Special Education Programs (grant #H327A070057) which worked to create an evaluation tool, using the WAVE evaluation framework, that provides feedback on some web page issues that may impact users with cognitive or learning disabilities. Adobe partnered with WebAIM so that the final product could be used as an extension to Dreamweaver.

A four phase process is being used to identify items to go into the initial cognitive evaluation tool. The first phase was to gather information from existing literature. The results of this literature review are below. Next, in order to rank items for possible inclusion into the tool, the WebAIM development team weighed the feasibility and importance of items (e.g., Is an item programmatically determinable? What is its impact on users? Will feedback on the item be useful to developers?) Third, with the item set narrowed, WebAIM sought the opinions of experts and developers regarding the importance and usefulness of select items. Finally, WebAIM will soon test items with users who have cognitive or learning disabilities to see if individual features make actual differences in their web experiences.

What follows is a condensed description of our literature review process and results. It is hoped that these results are useful to developers in the field now as they work to create web content that accessible to those with cognitive or learning disabilities. Moreover, since WebAIM will not be able to add all of the important features to its tool now, it is hoped that sharing our results can forward both research and the efforts of others in the field.

Method in brief

A systematic review of the literature was a first step in identifying the items to be placed in the first phase of this tool. This was a lengthy process. The hunt for potential articles began as staff members engaged in 252 separate web-based and library repository searches for information. We used 36 search term combinations (i.e., Disability, Cognitive, Mental, Learning, Internet, Computer, Technology, and Web) across 7 databases (i.e., Google, Google Scholar, JSTOR, IEEE, ACM, informaworld, and springerlink). We a set of criteria to determine which of the articles, published since the year 2000, would be included in the review (e.g., each had to explicitly include references to cognitive or learning disabilities, each had to focus on technology, and provide information on elements useful in web design). The result was an impressive set of 159 articles.

Each article was randomly assigned to one of 4 staff for primary analysis using a protocol developed for this review. All staff members were trained to use the protocol and reliably apply coding conventions. Fourteen articles (8.8% of the sample) were randomly selected for a blind secondary review and all 4 staff members participated in these secondary reviews. The inter-rater reliability for this process was 92.5% (calculated on a point-by-point basis), indicating reliable coding across staff.


What follows are brief descriptions of the items found in this review of the literature. Readers will note frequency counts along with each item. Although WebAIM staff counted the number of times any item appeared across the articles – and thus have a sense of which ones appeared more often – the numbers are not a valid measure of importance or prominence of any given feature. For example, if we read three different articles from the same set of authors describing variants of the same research, this result could appear 3 times. Since the literature was coded across several staff members there was no easy way to determine the extent to which the entire result contained duplicative analyses. Thus, although the frequency counts provide interesting information, the reader is cautioned against inferring a direct relationship of importance from those numbers.

Six categories or themes of recommendations emerged in this pool of literature. Below, each is described along with the components mentioned in the literature. WebAIM staff created the hierarchical structure that emerged in any category. It should be noted that these categories are not presented in rank order. Also, please note that the numbers that appear by each element are not additive within their category as some articles made direct reference to components and others made direct references to upper level categories. You may also view the full results of this review here.

Category 1: Conformance to Standards and Best Practices.

The literature under review contained 63 direct references to, or included components of, conforming to standards and best practices as a design element important to those with cognitive or learning disabilities. More specifically, the recommendation to use simple designs was by far the most prevalent (39 references). There were 23 references to using accessibility guidelines and standards; with 16 references to WCAG and only 4 references to Section 508. Recommendations for using principles of universal design, using simple content (as opposed to simple visual design above), separating content from visual design, and ensuring consistency through the site received a moderate number of references (between 15 and 18 references each). Interestingly, only 2 articles referenced following coding standards such as valid HTML and CSS.

Category 2: Common Design Elements

Common design elements were referenced directly, or through components that represent common design elements, 76 times. This result made the category the second most often mentioned across the literature reviewed. Design items that contributed to the ability of the user to navigate or interact with the site were referenced 54 times. This sub-category includes the importance of consistency throughout a site, limiting the number of options or steps the user is given, and providing large clickable targets, among others. Interestingly, recommendations to use a home button or contact mechanisms were rarely mentioned. It may be that including these design elements is now considered to be such common practice that that the authors did not feel the need to mention them as specific strategies in their articles.

Orienting the user and helping them avoid errors was viewed as another important design element; it was referenced 44 times. Here, the tried and true principles of providing instructions, prompts, and other error prevention strategies (33 references), along with error identification and recovery (21 references), were high on the list. Also on the list were recommendations to provide the user with alerts, feedback, and status indicators of their progress while interacting with elements on the site. The use of techniques such as breadcrumbs and tabs were also recommended in moderate frequency.

Items referencing user control appeared with moderate frequency in the literature reviewed (45 references). For example, the use of in-page controls, settings, or widgets (such as font-resizing controls) was referred to 18 times. The implementation or support of external user controls, such as user css, browser font sizing, etc. were mentioned 11 times. The use of cookies or user accounts to store user information or preferences for later use was mentioned infrequently (6 times).

Category 3: Language Use and Reading

Certainly developers know that providing simple language and an appropriate reading level for their content is important for all users, and clearly important for users with cognitive or learning disabilities. Our review of the literature revealed that elements of language (49 references) were mentioned more than components for either reading level or visual readability.  The most often mentioned language use item was the use of simple and appropriate language for the content (38 references). Reducing the amount of overall text was similarly called out across several articles, as was the need to avoid non-literal text, colloquialisms, jargon, or abbreviations.

It was surprising to us at WebAIM that although there were recommendations to watch out for reading level (10 references), specific reading level recommendations were only mentioned in 3 articles and there was not agreement on what that level should be (e.g., from 6th grade reading level to no vocabulary beyond 3 syllable words).

The elements that enhance the visual readability of text were mentioned at relatively low levels for their perceived importance. Font size (14 references), line length (11), line height (10), adequate contrast (9), and sans-serif fonts (6) were mentioned, but relatively few times.

Category 4: Enhance Comprehension

There were 80 direct references to, or specific techniques referencing the need to enhance comprehension. Thus this category was cited more often than any other single category. Although most of the recommendations found in the literature reviewed share an end goal of enhancing user comprehension of web-based content, there are several specific design techniques that emerged to address comprehension directly.  At the top of the list were recommendations to use multimodal or enhanced content specifically designed to target comprehension (71 references). The use of both images (54) and audio or other multimedia (52) were frequently mentioned as exemplars of this.

Many articles made reference to the importance of alternative formats (47 references) with compatibility to screen readers or self-voicing technologies appearing in moderate levels (38 references). The use of captions and transcripts were identified as helpful for those with cognitive or learning disabilities, albeit at low levels.

Other techniques to enhance understanding included creating a visual difference, for example with the use of bold, color, or font, and also highlighting or otherwise identifying important information. Less mentioned was the presentation order of content or the use of repetition to increase comprehension.

The frequency with which literature review items appeared in this category may rest in the fundamental notion that learners develop different styles to learn based on areas in which they have strengths. Providing multiple mechanisms for the user to interact with content could certainly enhance their ability to understand it.

Category 5: Structure

The use of structural items was mentioned in the literature (29 references) as a mechanism to assist the comprehension of those with cognitive or learning disabilities.  These include fairly intuitive principles such as chunking or grouping content. It also included fairly intuitive structural elements such as the use of proper headings and lists (17 and 13 references respectively). It was interesting to us that the use of whitespace was identified frequently in the literature (14 references) as an element of document structure. While whitespace does reside conceptually in the “Readability” category (as “line height” and perhaps “line length”), it’s frequency in relation to document structure makes sense since the use of whitespace is a visual structural companion - its presence on a page enables the user to detect the structural elements that have been have placed on a page.

Category 6: Elements of Attention and Distraction

Designs that are helpful to users with cognitive or learning disabilities implement techniques that pull the attention of the user toward content and avoid distracting the user from content. In the literature reviewed, there were 26 explicit references to this principle. Most of these references were recommendations for developers to avoid items that introduce distractions (21 references). These were identified more specifically as distracting animation or movement, movement of or changes in the content itself, and the use of pop-up windows. Employing techniques to focus the user’s attention to content was also mentioned in the literature but at a relatively low level (12 references). Such techniques specifically included using color, movement, and/or non-text elements to focus the user on content.

In the future WebAIM will post additional articles that detail our progress in developing a tool to assist developers in creating web content that can be used by those with cognitive and learning disabilities. If you are interested in any aspect of this project, WebAIM invites you to contact us.