Attention spans online are short, so you need to design sessions which give attendees reasons to stay interested and motivated. You want enthusiasm from your audience! How do you do this?
Focus on learning objectives that matter
Keep your session streamlined and focused on learning objectives. If these objectives have been designed for face-to-face session, review and reduce them to concentrate only on the most critical.
Understand your audience, so you can pitch the learning objectives appropriately. What do they already know, and what do they need to get from the session? You may want to send a quick survey to participants in advance, to help you check you are on the right track.
What's the difference between a 'live virtual classroom' and other forms of online learning?
Virtual classroom/instructor-led training: Small sessions (fewer than 20 attendees) with interactivity and participation. Similar to a face-to-face workshop.
Webinar: For larger audiences, typically a one-way presentation perhaps with facilitated Q&A. Can be recorded and accessed later. More like a conference presentation.
E-learning: Self-paced, self-study solutions delivered digitally. Resources don't rely on live delivery by a facilitator.
This is also a good time to reflect on whether a virtual classroom is the best fit for what you're trying to achieve.
Borrow but don't import from face-to-face
If you're moving from face-to-face delivery, don't attempt to move your existing course into a virtual environment wholesale. Face-to-face session plans can be a good starting point for ideas, but the content will need adapting to be successful online.
Sessions almost certainly needs to be shorter, or split into more than one event.
How many people, and how long?
If you're aiming for interactive 'virtual classroom' learning, 10-15 people is ideal. If numbers creep above 20 then you're into webinar territory, which is more one-way presentational style.
For a virtual classroom, the session length is ideally 90 minutes to two hours. For a two-hour session, include a comfort break half way through.
Keep it moving, keep it interactive
To maintain interest, the session needs to be varied in pace, with frequent interactivity. Use a blend of types of activity, combining short amounts of facilitator-led input with participant involvement.