Sample size is a red herring. If the difference is big and stark enough, you can detect it even in a MUCH smaller sample than this. You only need a big sample if the difference you are looking for is subtle.
Mind you, this is assuming that the sample has been taken in an unbiased manner (nigh impossible in a voluntary survey like this) and that any conclusions you draw are applied only to the population you took the sample from (e.g., if your sample is undergrad psychology students at a particular university, your results apply only to undergrad psychology students at that particular university, not to the general population).
The issue is not the sample size. It's the sampling method. Even if you do a study on 1 billion people, your are liable to get an incorrect result if you don't take the sample correctly.
Of course, the other issue here is that we are claiming something that the study didn't actually cover. The researchers did not look at whether the subjects succumbed to the bystander effect or not: they just looked at how the subjects answered questions. These are two extremely different things! This is bad experiment design.
Mind you, this is assuming that the sample has been taken in an unbiased manner (nigh impossible in a voluntary survey like this) and that any conclusions you draw are applied only to the population you took the sample from (e.g., if your sample is undergrad psychology students at a particular university, your results apply only to undergrad psychology students at that particular university, not to the general population).
The issue is not the sample size. It's the sampling method. Even if you do a study on 1 billion people, your are liable to get an incorrect result if you don't take the sample correctly.
Of course, the other issue here is that we are claiming something that the study didn't actually cover. The researchers did not look at whether the subjects succumbed to the bystander effect or not: they just looked at how the subjects answered questions. These are two extremely different things! This is bad experiment design.