Читать книгу Interpreting and Using Statistics in Psychological Research - Andrew N. Christopher - Страница 28

There are two different broad categories of statistics, and each one has a specific purpose. With descriptive statistics, we are organizing and summarizing a body of information. We will discuss descriptive statistical tools at length in Chapters 2 through 5. Descriptive statistics are useful for learning about the characteristics of our sample. For instance, Pam Mueller and Daniel Oppenheimer (2014) conducted a study to learn whether college students (the population) retain more information when taking notes in class with a computer or with a pen and paper. They sampled college students and measured their performance on test questions based on which note-taking method they used. They calculated certain statistics, such as those we will encounter in the next four chapters, to compare the performance of students using the two different note-taking methods in their sample.

Although descriptive statistics are vital to research, we tend to be more interested in drawing conclusions about a population based on information from our sample. And, again, most always we cannot collect information from everyone in our population, so we rely on our sample to make inferences about the population. In that situation, we use inferential statistics. The purpose of inferential statistics is to draw an inference about conditions that exist in a population by studying a sample drawn from the population. We will learn about different inferential statistical tools in Chapters 6 through 14. Mueller and Oppenheimer (2014) were interested in learning about how note-taking was related to academic performance in a population of college students. Not being able to test all college students, they sampled students from Princeton University and UCLA. From this sample, they drew conclusions about college students and the effects of how they take notes on test performance.

Descriptive statistics: quantitative procedures that are used to organize and summarize (describe) information about a sample.

Inferential statistics: quantitative procedures that are used to learn if we can draw conclusions (inferences) about a population based on a sample.