How much course content should appear on a single web page?

According to Web Usability expert Jakob Nielsen, "reading from computer screens is about 25% slower than reading from paper." Nielsen recommends writing 50% less text.

At one extreme are the PowerPoint slide shows, where a small amount of content that is entirely visible in the browser window shows up, and the student clicks NEXT or BACK to navigate around in the slide show, seeing only one slide per "page" at a time. The other extreme is to include an entire unit on a single web page, so that the student has to scrolls as far down as needed to read through the unit. In between those extremes are sections broken into smallish segments, somewhat larger than the browser window but not requiring too much scrolling. Then the student needs to navigate between pages to read the unit.

Which is better? There are benefits to both. When an instructor authors a module, they tend to do so as a whole -- a single word or HTML document. When it is a single document, it is easy to reorder, rearrange, or make large scale global changes. On the other hand, students report liking to have the content in smaller, more managable segments. Ideally, the module is segmented into meaningful "pages" based on key concepts. Rather than just calling it "page 2 of 6" calling it "page 2 of 6: island ecosystems" helps make the student more aware of the conceptual structure underlying the module.