The Basics of Statistical Inference: Tests of Location
Earlier in the book, we devoted considerable time and space to a discussion of ways to describe sets of scores in meaningful ways. At that point, our focus was only on the scores at hand; they constituted our population of interest and the quantities derived could be considered parameters. Specifically, we described ways to summarize and present information about location, spread, and shape, with size (n) being a given. Such activity is often described as descriptive statistics. Exploring/describing data is an essential activity. Through exploration and description, we may see patterns and relationships and begin to wonder if these patterns might be generalized beyond the data at hand. That is, we question whether what we are seeing in our data might also be seen in other sets of data. These questions are often called research questions. Based on our knowledge and/or previous experience, we might formulate tentative answers to our questions. These tentative answers are called research hypotheses. As the term implies, these answers are hypothetical and need to be supported or refuted based on new data. To address this concern, we engage in inferential statistics.