Pcullum,
You hit me right up my alley with this question. I have actually completed a thesis study on this topic many years ago. I was surprised at the responses and the depth of responsive's I received from the students that were polled. But it is good to read through the responsive's that the members have responded with closely correlate to those polls.
Most students were not concerned with the length of the videos as long as all the important aspects of the topic were covered. They wanted good, in-depth information on the topic, they wanted the presenter to speak clearly and explain in detail what was occurring in the videos. One of the most important aspects that were brought up over and over was that the exercises had to work. When I dug deep into this I found that many of the students had attempted to complete video tutorials on line that did not work as they were presented. The presenter left something out or did explain something clearly and that caused the entire exercise not to function correctly.
That may sound silly but if the presenter does not accurately explain the environment that he is developing the tutorial in, and the students environment doe snot match that work space, the lab exercise may not work.
Many of the larger learning sites limit or attempt to limit there video to 5 to 10 minutes per topic. On many topics, especially in programming, web development, web design, etc, that is just not enough time to cover a topic with any degree of completeness. I am not certain if you have seen any on my videos but many of them, especially on the more complex programming topics can run over 30 minutes.
I developed an HTML course that runs over 26 hours, but it is based on a college course I teach and covers everything I cover in that semester. I did the same thing with a Bootstrap course that I wrote for the web. It is over 24 hours of video and covers the semester course on Bootstrap.
I am working on a CMS (Content Management System) course for developing your own CMS and the way the development is going it may be well over 30 hours. And that course will have prerequisites in HTML and CSS that will need to be understood prior to taking the course.
By the way those two long courses on my site are very popular and sell quite well. Of course part of that is that they are priced very well for what you receive.
So it is not about length, it is about content, completeness and accuracy. Cover what needs to be covered, cover it well and make certain to fully explain and demonstrate the process.
Let the complexity of the subject determine the length. Some tutorials may be a few minutes, others may be much longer. You will be able to tell when you hit the right mark by the feedback from your users.
