For the more advanced user of WebCT Vista, Blackboard Learn 9, Angel, etc., who uses web technologies to design rich, visually striking, interactive learning content, there is a perpetual thorn in the side: quirks mode. What is quirks mode? In short, any time the doctype code on an html page header is not done properly (and the first thing the browser sees), most web browsers go into quirks mode to try to compensate for a web page that seems broken. Usually the web browser renders the page as an older version of that browser.
If you use html to create course content to upload into your online course, you’ve probably seen some of the problems caused by this, even if you didn’t know the cause. Most of the problems are caused in Internet Explorer, which renders as IE 5.5 or 6. So any html page you create to upload into an LMS system must be designed to work in IE5.5 or 6, or it will break for your students, even if they are on IE 8 or 10.
For more information on what breaks in different browsers I quirks mode, have a look at quirksmode.org’s excellent guide. It could lead you to the cause of the persistent, mysterious, illogical html problem you’ve been having in your online course: