Hi DCR – Week 3 is all about sample size. This is traditionally one of the hardest weeks of the course, where you’ll have to squeeze your research question into a completely rigid framework in order to actually do a sample size calculation. You may also have to guess at various parameters (e.g., the standard deviation of a continuous measurement) and make somewhat arbitrary decisions about effect size...that’s all par for the course. Remember your goal: to complete at least one sample size calculation that is relevant to your study, and be able to translate that calculation into a description in English that is essentially a quantitative argument for why the result of your calculation means your study will be both feasible (you can get data from that number of people) and important (you’ll have adequate power to detect an important effect size).
I encourage you to get a head start on this. I’ll be available to chat tomorrow during my usual Friday office hours from 10-11 tomorrow (Zoom info on CLE) – bring questions and we’ll try to get through a calculation for you in real time if you like! And this will be the primary topic of your small group sessions next week.
Good luck!