I recently examined these and other questions in an article on elearning usability published by trainingindustry.com. It’s available online at http://www.trainingindustry.com/learning-technologies/articles/improving-e-learning-usability.aspx.
It isn’t hard (or expensive) to make your elearning easy to use and engaging, but it is something that needs to be planned. Good elearning should consider the quality of the learning, the quality of teaching, the quality of the learning environment and the quality of interaction. If you create elearning that’s strong in all of those areas and is relevant, learners will get more out of it. Your learner’s time is valuable and should be spent learning the subject matter, not your system.
Testing for usability issues in elearning should also be on every learning professional’s radar. This is not something you and your team can do yourselves; you’re too close to the project, as are your other key stakeholders. Get testers who are representative of the audience, plan your testing, and make sure you observe rather than coach. For professional help with elearning usability testing, take a look at eLearningQA.com.