Sampling method: different ways to choose a sample from a population would be a sampling method. For example, sampling every fifth person who walks into a market about baseball would be a good sampling method since it is not biased.
Generalization: a broad conclusion made about a population based on observing a sample. This would be just a generalization since it is a broad conclusion discluding important elements like facts and statistics.
Valid generalization: a conclusion that is made based on supporting facts and statistical analysis. This would be a valid generalization since it is a conclusion including facts and statistics which makes it valid.
Biased sample: a sample in which not all members are equally likely to be selected is biased or seems like it wouldn't be fair.
Unbiased sample: a sample in which all members are equally likely to be selected is unbiased since everyone is equally likely to be selected.
I hope this helps:)
