One specific choice you’ll need to make is whether participants need to take part all at the same time (synchronous) or can take part when best suits them (asynchronous). Again, this will be determined to a large extent by your purpose.
If your purpose requires participants to deliberate intensively with one another, this will likely be best achieved by bringing them together at the same time via a video-conference where engagement is deep and discussion can flow. On the other hand, if a less intensive form of discussion is adequate, then an online forum where participants can post at a time that best suits them may be more open and inclusive. If participants do not need to discuss or interact at all, then asynchronous participation will likely be the obvious option.
Synchronous and asynchronous participation can be blended together as part of an engagement process, either with the same group or different groups of participants. This is likely to be the best option for an in-depth process – such as a citizens’ assembly – which requires participants to undertake a range of activities (e.g. learning, discussion, deliberation, voting, etc.).