Objectives
Lecture 10 · p.2- Understand the importance of sample size calculations
- Understand the principles of sample size calculations of binary and continuous outcomes
- Relation between sample size calculations and power calculations
Slide errata
1L6 p.23 and Reality Check 2 (p.66) · Tension with standard theory
The slides say 'Alpha error decreases as the sample size increases' and mark L6 RC2 ('You can decrease alpha error by increasing the sample size') True. In standard theory alpha is fixed by the chosen threshold (e.g. 5%) whatever n is; a larger n reduces beta.
what the exam expects:True: alpha error can be decreased by increasing the sample size (the module's answer).
How the app teaches it: Teach the module's answer for exam purposes, and flag that in standard theory α is fixed by the threshold and n reduces β.
Why sample size matters