3 ms·

I'm not sure that I follow. Why is the worst-case standard deviation 5%? And for which random variable? I vaguely do remember the standard way of coming up wit

I'm not sure that I follow. Why is the worst-case standard deviation 5%? And for which random variable? I vaguely do remember the standard way of coming up with a reasonable sample size. Assuming: 1) We want the commonly used confidence level of 95% (corresponding to a a Z-score of ~1.96). 2) We want a margin of error of 1 percentage point (kinda reasonable, since their estimate is stated as a percentage without explicitly stating the margin of error). 3) We don't know anything about the expected percentage of bots a priori. 4) We ignore the error in determining an account is a bot or not. Then, we'll need a sample size of 1.96^2/(2*0.01)^2 = 9604.

azakai 4y ago
(See below for two answers about the math that gets to 5%.) > We want a margin of error of 1 percentage point (kinda reasonable, since their estimate is stated as a percentage without explicitly stating the margin of error) If the question they want to answer is "give me the exact % of bots on Twitter", then yes, you probably want a standard deviation of less than 1%. That would take many thousands of samples, as you say - much larger than sample sizes used in presidential elections, even. OTOH, my guess is that the question for them is "are bots a big part of the Twitter population?" In that case, 97% of accounts being real versus 96% doesn't matter much, since both show bots are a very small group. (But maybe bots write a disproportionately large # of tweets?)