Minimum detectable effect size for main outcomes (accounting for sample
design and clustering)
Our primary outcome of interest is the number of conversational turns between parents and children. Based on the baseline distribution of conversational turns in Ellwood-Lowe et al. (2020), with our expected sample size of 100 households, this corresponds to an MDE of 6.79 conversational turns off a mean of 28.19 using just three days of recording data. Our study will have 20 days of recording data from general audio recorders, plus the three days of data using the specialized LENA recorders used in this previous work. Consequently, we expect our statistical power to be substantially higher than previous work. However, this is only preliminary, and we will update these power calculations before launching the full study.