Layout, media and appearance are not only important for aesthetic reasons but most importantly for comprehension purposes.  Angie Millman, director of Disability Support Services at Seton Hall University in 2013 outlines important guidelines to consider when designing a course (http://blogs.shu.edu/technology/files/2013/05/ADA-Compliance-Considerations-and-Best-Practices-for-Accessible.pdf ).  The course should be accessible to all students and provide accommodations for students with visual, audio and other disabilities.  For example, images that flicker at too fast a rate may cause seizures in individuals with seizure disorder.
The following are standards Millman recommends for designers to consider with media, layout and appearance:

• Perceivable: Information must be presented in a way the students can perceive regardless of their disability.
• Operable: Enough time to operate and access the information.
• Readable:  Make sure the text content is readable and understandable.  For example, minimize screen clutter or distractions.  If using color, make sure there is enough contrast.
• Predictable:  Pages should appear and operate in predictable ways.  For example, the position of the next button should be consistent.
• Navigable: Provide ways to help students find content and determine where they are.

Five Sites Which Exemplify Sound Design Ideals

1. Mountain Heights Academy http://www.mountainheightsacademy.org/ – The site is very well laid out.  It is perceivable, operable, readable, predictable and navigable with the navigation bar at the top of the page.
2. Khan Academy https://www.khanacademy.org/ – This site is very well laid out.  Students can find topics pertaining to their subject and navigate from topic to topic easily.
3. Learn Zillion https://learnzillion.com/ – Similar to Khan Academy.  Students can find topics that they need help in and navigate easily.
4. MIT Open Courseware http://ocw.mit.edu/index.htm – This open course website allows students to take college courses completely free from MIT professors.  It is very nicely laid out.  In addition, each lesson has a transcript of the video as well as video notes.
5. Yale Open Courseware http://oyc.yale.edu/

Honorable Mention: CK12 http://www.ck12.org; Patrick JMT Math Help http://patrickjmt.com/

Five That Do Not Adhere to These Standards

1. Purple Math http://purplemath.com/modules/absolute.htm – While this site has a lot of good instructional information, the placement of ads which clutter the page does not adhere to the readability standard.  There are many links that take the reader to a totally new website which makes the site navigation difficult.
2. Cool Math http://www.coolmath-games.com/ – This page has clutter and ads which are distracting.  The background makes the readability difficult.
3. Paul’s Math Notes http://tutorial.math.lamar.edu/ – This page is cluttered with words which makes readability hard and overwhelming to the reader.
4. Math Cats http://www.mathcats.com/explore/river/crossing.html – The images on this page are distracting and frequency is very fast which might lead to problems for individuals with seizure disorders.
5. Web Math http://www.webmath.com/index1.html – The font on the website is very small and the page is cluttered with ads that have nothing to do with the topics.