Statistics and Statistical Programming (Fall 2020)/w07 session plan

10/29 Agenda[edit]

OS Ch 7 exercises
- What to do with/about violations of assumptions? (e.g., 7.12b)
- Causality (again)
  - 7.12c: Did the lead do it?
  - Trick-or-treating experiment from Aronow et al. (Tuesday): did the treatment do it?
T-tests "in the wild"
- What should/can you do with this test?
- What concerns should you have / take into account?
Big picture considerations revisited:
- What to do with any test?
- How do I know whether I'm using "the right" test when there are seemingly no rules and/or whatever rules exist seem to be breakable (sometimes)?
Self-assessment exercise demo/introduction

Pset 5 PCs
- PC4: interpreting the results of this chi-squared test
- plotting error bars, and walking through some of the techniques Aaron used in the PC5 solution
- review: calculating standard errors.
  - What if don't have raw data (EQ2)
  - Should I use special formulas from a textbook (such as the formula for SE of a proportion) or the default formula (sd / sqrt(n) )?
- Other questions?
Pset 5 EQs
- Base rate fallacy
  - Review the definition
  - How concerned should we be?
- P-values
  - the "strength" of relationships
  - significance of differences rather than differences in significance
- Chi-squared in particular
  - Goodness of fit? Test if the distribution fits the data?
Meta-questions (many via Gus's comments)
- The practical the purpose of a statistical test (is to find the p-value)?
- What should you ask about any test?
- What do we know about causality from any of these tests?
Other questions
Upcoming
- Project plans
- Stats material this week
- Assessment coming. Discuss some details, goals of the activity, etc.
- No problem set is due on Nov. 3 (election day!)