| A | B | C | D | |
|---|---|---|---|---|
1 | For binary items (Ex: yes/no, agree/disagree, did/did not, have/have not) | |||
2 | You fill in the yellow boxes. | Notes | ||
3 | Total student population in that student group in the university (N) | 588 | If you're looking at the 337 Female-identifying varsity athletes at your university of 25,000, the population number of interest here is 337. N = 337 | |
4 | Total respondents for the item and in that student group (n) | 28 | If 42 of your 337 Female-identifying varsity athletes answered the item, the number you need here is 42. n = 42 | |
5 | Proportion dis/agree in the item relative to total respondents, not population (p). | 62% | Let's say you split the answers to a Meaning pathway item into two bins: one for everyone who "strongly disagreed" - "slightly disagreed", and the other for everyone who "slightly agreed" to "strongly agreed." If you want the confidence interval for the 30% of those 42 students who were in the "agree" bin for the item, the number you need here is 30. p = .3 or 30% | |
6 | ||||
7 | Everything else is calculated for you. Nothing to fill in here! | |||
8 | With FPC | Without FPC | ||
9 | ||||
10 | N <= 5000 | N > 5000 | N = population size, not sample size (row 3) | |
13 | Confidence Interval (CI) values | These are the numbers you are looking for! | ||
14 | Report either the 95% values (both of them) | People usually report either the CI values or the margin of error values. | ||
15 | 95% CI upper bound | 79.6% | 80.0% | A 95% CI is a fairly conservative estimate. We normally use this in high-stakes situations, such as deciding which of several programs to keep. |
16 | 95% CI lower bound | 44.4% | 44.0% | |
17 | 95% margin of error | 17.6% | 18.0% | |
22 | ||||
23 | Reporting examples | General notes | ||
24 | 62% of the 28 students who answered this item agreed/disagreed with it (95% CI with finite population correction was 44.4%-79.6%). | This calculator uses a z-distribution. You can see more about the finite population correction and margin of error calculations here: | ||
25 | https://www.r-bloggers.com/understanding-margin-of-error-for-small-populations/ | |||
26 | ||||
29 | ||||