Lesson 2: Frequency Distributions and Central Tendency
Introduction
In this lesson you will encounter the concept of a distribution for the first time. A distribution simply arises due to variations in performance. Such variations can be between individuals, differences within individuals over time, or they can even be variations in the size of CDs made by a particular machine. The concept of a distribution will come back throughout the course in different forms.
You will also learn about measures of central tendency. These measures, such as the average score of people on some test, provide a useful measure of behavior across people. Of course people differ from one another, but for many types of behavior people also are remarkably similar. A basic assumption of much psychological research is that the way in which behavior is controlled in one individual will be similar to the way in which behavior is controlled in another individual. By taking the average behavior of many people, one can thus study how most people control certain behaviors. Let’s get started!
Learning objectives:
At the end of Lesson 2 students should be able to:
- Explain how frequency distributions and central tendency act as descriptive statistical techniques.
- Display frequency distributions as tables and graphs. Such tables include both regular and grouped frequency tables, and such graphs include bar graphs, histograms, and polygons.
- Describe the three different measures of central tendency, the mean, the median, and the mode.
- Describe the relationship of the three measures of central tendency to the shape of distributions.
At this time please open your textbook and begin reading Chapter 2 and Chapter 3. When you are finished return to this page and click next to finish reading the instructor commentary.