Timeline for Sample size choice with binary outcome
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 21, 2016 at 23:41 | history | bounty ended | mmann1123 | ||
| Apr 19, 2016 at 17:38 | comment | added | soakley | To get the desired accuracy on both strata will require much more sampling. With 1875 nonminority households you will need 237 data points, and with the 625 minority households you will need to sample 190. If you have reason to believe the true success probability is much different than 0.5, then you can improve on these using the first formula for $n$ in the answer. | |
| Apr 18, 2016 at 22:37 | comment | added | Matthew Gunn | With the minority question, Soakley may be alluding to that different groups may have different survey response rates? Eg. if old people oppose some measure (eg. school funding) and respond to surveys at higher rates than young people, you may underestimate support for school funding in the population by looking at survey responses. Anyway, you can get into extremely tricky issues if various covariates (eg. age) are linked with both public opinion and survey response rates. | |
| Apr 18, 2016 at 21:14 | comment | added | soakley | Make sure you square the $z$ factor. | |
| Apr 18, 2016 at 21:13 | comment | added | mmann1123 | I am not getting the same result: (1.6449*2500)/(1.6449+4*2499*0.05^2) =154.3933. Clearly I am missing something. Can you see what I did wrong? | |
| Apr 18, 2016 at 20:51 | vote | accept | mmann1123 | ||
| Apr 18, 2016 at 18:53 | history | answered | soakley | CC BY-SA 3.0 |