# Chapter Main Points and Learning Objectives

Chapter main points

• Statistics are procedures used by social scientists to organize, summarize, and communicate information. Only information represented by numbers can be the subject of statistical analysis.
• The research process is a set of activities in which social scientists engage to answer questions, examine ideas, or test theories. It consists of the following stages: asking the research question, formulating the hypotheses, collecting data, analyzing data, and evaluating the hypotheses.
• A theory is a set of assumptions and propositions used for explanation, prediction, and understanding of social phenomena. Theories offer specific concrete predictions about the way observable attributes of people or groups would be interrelated in real life. These predictions, called hypotheses, are tentative answers to research problems.
• A variable is a property of people or objects that takes on two or more values. The variable that the researcher wants to explain (the “effect”) is called the dependent variable. The variable that is expected to “cause” or account for the dependent variable is called the independent variable.
• Three conditions are required to establish causal relations: (1) The cause has to precede the effect in time; (2) there has to be an empirical relationship between the cause and the effect; and (3) this relationship
cannot be explained by other factors.
• At the nominal level of measurement, numbers or other symbols are assigned to a set of categories to name, label, or classify the observations. At the ordinal level of measurement, categories can be rank-ordered from low to high (or vice versa). At the interval-ratio level of measurement, measurements for all cases are expressed in the same unit.
• A population is the total set of individuals, objects, groups, or events in which the researcher is interested. A sample is a relatively small subset selected from a population. Sampling is the process of identifying and selecting the subset.
• Descriptive statistics includes procedures that help us organize and describe data collected from either a sample or a population. Inferential statistics is concerned with making predictions or inferences about a population from observations and analyses of a sample.

Learning objectives

1. Describe the five stages of the research process
2. Define independent and dependent variables
3. Distinguish between the three levels of measurement
4. Apply descriptive and inferential statistical procedures