The Connected Learner has an interesting post on how long you should make an e-learning course. Among the factors to consider are:
- Audience
- Management Desire
- Does the course have to be taken at one time or can it be spaced
- How much time does the audience have?
- Does the course consist of Content, Practice, or Testing
- What extras does the course have
- Is it a single course or multiple courses
You can read the entire post at The Connected Learner: Self-Paced Elearning: How long is just right?