Recommendations
The main organizations involved in the standardization of web technologies are the W3C and the WHATWG. A leading role in accessibility recommendations is the Web Content Accessibility Guidelines (WCAG) standard, which was developed by the W3C consortium. It makes specific recommendations for web content that are tailored to different devices and programs.
The methodology for increasing the level of accessibility of learning resources includes the following principles:
Add ability to increase font size in web page if desired by visitor
Increasing line spacing for longer paragraphs to make them easier to read for people with visual impairments and dyslexia
A color scheme providing good contrast between text and background, or an option for the visitor to choose a scheme. The classic scheme of black letters on a white background (for text, cell, box, box, table, header and footer) is the most comfortable for colorblind people
Font selection on a web page for smooth reading. Fonts such as Arial, Helvetica, Verdana and Calibri from the Sans-serif family are better readable for students with visual impairments (including dyslexia) because they reduce the reading load
No text in capital letters only, avoid italics and word underlining
The text should be effectively structured in small portions according to the priorities of the information in order to easily and quickly navigate and remember when reading
Multimedia Recommendations
Adding to each image (and other visual elements) descriptions via alt text (via the alt attribute) or via a caption (via the <figure> and <figcaption> tags)
It is recommended that alt text conveys the content of the image and its purpose in one or two sentences
Icon-based interface to include larger and contrasting images and accompanying descriptive text
Descriptive text for a visual element should not repeat the text before and after the visual element
Add subtitles to video and audio elements to facilitate hearing impaired visitors
Avoid including diagrams related to learning, because reading and describing them is not equivalent to the diagram itself and would not have the same effect in understanding the interrelationships between elements
Recommendations for links and navigation
Set greater distance between individual buttons and between selection options
The color scheme should provide sufficient contrast with the color squares of the links
Link labels should be short, clear, precise and descriptive
The labels should give a clear idea of their direction independently of the other links in a menu
To add an effective site navigation system - information on the path taken ("breadcrumbs") to a learning resource, links to previous related lessons, recall of definitions and statements
Avoid tables of data, using paragraphs and lists instead
If tabular presentation is required, do not include merged cells because they make it difficult to read the content with a program
Do not nest tables inside each other, because the content is difficult for a program to read and for the visitor to understand
Don't leave blank cells in a table because processing them by a screen reader can confuse visitors
Add column headings to tables with tags <thead> and <th> because they make it easier to navigate the visitor in the table data
Do not use tables with fixed sizes, because reading them for people with impaired vision (through a magnifying glass or zooming in the browser) becomes difficult