The sample size is the number of independent observations made on the population. Just as it would be invalid to generalize about all people from a given country based on conversations with two of its citizens, it would also be invalid to generalize, for example, about a community of insects inhabiting a grassland based on observations from two sweeps of an insect collection net. In general, we will want as large of a sample as possible. This will improve our confidence that the estimate we generate from the sample is close to the actual parameter we are interested in knowing.
