I am researching program effectiveness by comparing learning outcomes from two different instruction methods. We did live webinar training sessions (collected pre and post surveys) and then we reused this same webinar (as a recording of the live webinar) and posted it for people to watch at a later date (also collected pre and post surveys). I want to determine if watching the exact same content live or recorded changes the observed learning outcomes. What would be the best method to use? The surveys were recorded but are anonymous.
For a little more detail, the surveys were the same pre and post for each training whether it was presented live or recorded. There is a total of six different training webinars I will compare. Each had their own pre/post-survey. I want to compare each one individually and then combine all data for an overall difference. The answers were (strongly disagree, disagree, neutral, agree, and strongly agree). I am also having a hard time figuring out how to determine the needed sample size for the recorded webinars to achieve reliable results. The live webinars averaged 250-300 participants.