The Power of Statistical Tests
In the social and behavioral sciences, statistics serve two general purposes. First, they can be used to describe what happened in a particular study (descriptive statistics). Second, they can be used to help draw conclusions about what those results mean in some broader context (inferential statistics). The main question in inferential statistics is whether a result, finding, or observation from a study reflects some meaningful phenomenon in the population from which that study was drawn. For example, if 100 college sophomores are surveyed and it is determined that a majority of them prefer pizza to hot dogs, does this mean that people in general (or college students in general) also prefer pizza? If a medical treatment yields improvements in 6 out of 10 patients, does this mean that it is an effective treatment that should be approved for general use? The goal of inferential statistics is to determine what sorts of inferences and generalizations can be made on the basis of data of this sort, and to assess the strength of evidence and the degree of confidence one can have in these inferences.