18  Quiz — Day 2

19.1 Question 1

A researcher partners with the Ministry of Agriculture and they collect data from a random sample of farmers. The survey asks two main questions. (1) Have you made use of extension services in the last year? (2) What was your yield per hectare in the last two years? The researcher finds that the yield is twice as high for those who used extension services than for those who did not. He tells the Ministry that extension services increase yields and that they should scale up the extension services to all farmers.

Does the analysis support the researcher’s recommendation?

19.2 Question 2

What is the fundamental problem of causal inference?

19.3 Question 3

I’m conducting a study and need to send an informational email to exactly 100 participants, with the rest (the other 100) receiving a control email. The only information I have about these participants is their email addresses.

Should I randomize using simple, complete, blocked, or clustered random assignment?