The purpose of the site is to teach the various types of coding for a beginner user in the world of coding. Various coding styles are included.
No, W3 schools home page does not validate.
No, the second page does not validate.
W3 schools home page-42 errors
Where to Start-36 errors
I rate the site's design a 7. I like the spacing and examples of code. The things I don't like: Is the astronaut a squirrel? Do squirrels or space have anything to do with the topic of coding? My eyes are overwhelmed with the color of CSS, bright yellow. I'm disappointed that a site is dedicated to teaching HTML, but doesn't have a clean page without errors at W3C. "W3" is in the website's name but when I searched "validate", "validator" and "W3c", it yeilded no results on the site. Sometimes the search function had errors and didn't yield anything on the site or the web.
I rate the rate the site's usability a 8. It has useful information I can use right now. The words are easy to read (size and color) and defined so I could have a very basic understanding of the topics. It has example boxes to try right now, search boxes and "Not Sure Where To Begin" below the main search box. I'm disappointed the search isn't better, as mentioned above.
Yes, the site meets the purpose, "to teach various types of coding". The quizzes and interactive boxes are a nice touch and invites the user to interact instead of all words which can be boring.