Is asynchronous or synchronous more effective? I see this question or discussion from time to time. The research suggests this is a *very* nuanced decision point. Neither is really better as far as differences in learning outcomes. They're just sort of options to choose from. BUT

Context and circumstances are king here. Learner characteristics, the learning context, and even the objectives and the nature of the content and different strategies will start to suggest using asynchronous or synchronous (or a blend throughout your class).

Typically, if you're working with adult learners who are more self-regulated and who have busy lives and schedules that don't match up, asynchronous will be a better fit for them. It doesn't impact learning outcomes, but it DOES impact flexibility, ease of access, etc.

Even then, you may be teaching something where the objectives or nature of the content suggests some synchronous. I teach adult learners across time zones. I also teach design and use a studio-based method. Our class is 90% asynch with some periodic synchronous design group mtgs.

If you're teaching 4th graders online, though, having regular synchronous (not too much) can help set a rhythm, provide structure, and ensure the learners who need support get it. We know that learners who most need supports are very unlikely to participate in anything optional.

But there's still no hard & fast rule. Some online graduate programs for example have required 3-hour (or however long) weekly synchronous sessions, and students in those programs love it. What we do know is that whether you use sync or async, the *strategies* you employ are key-

-specifically, strategies for engaging learners with the content. I really like the Performance Content Matrix from Morrison, Ross, Kalman and Kemp for thinking through strategies because it helps align strategy with type of objective. But I'm a formalist.

But assuming you use effective strategies, the mode doesn't really matter (i.e. doesn't have an effect on learning outcomes). Some folks prefer one or another because it maps better to their teaching style, and that's totally fine as long as it's not erecting barriers to access.

The best sources for this conclusion from the research IMO are Means, Bakia & Murphy, 2014, Learning Online and Bernard, Abrami, Borokhovski, Wade, Tamim, Surkes, and Bethel, 2009 - this is a passing mention in Bernard et al but the clearest statement IMO.

@hodgesc shared this great easy-to-read article on the topic with me, passing it along here: https://er.educause.edu/articles/2008/11/asynchronous-and-synchronous-elearning