How to Identify Independent & Dependent Variables in the Study of Political Science

The study of political science is the marriage between the humanities and the social sciences. Political scientists often study people’s choices when they're engaged in political behavior. Studies evaluate people’s choices, beliefs and opinions, and through this analysis, scholars seek to better understand humanity.

What Are Variables?

When studying the political sciences, observers focus on one or two characteristics in need of investigation. For example, a political scientist might wonder how gender affected the voting behavior in a certain election. The characteristics the scientist wants to study are called variables. Scientists call these characteristics variables because they can differ from one person to the next.

Characteristics that don’t vary – in other words, characteristics that don’t tend to differ from one person to the next – are called constants. A constant will remain the same throughout a study. For example, if an investigator studied the voting behavior in Boca Raton, Florida, the city location would be the constant, and the voting behavior would be the variable.

What Is a Dependent Variable?

A dependent variable is the variable under investigation. A study would analyze a dependent variable to try to understand why it differs from one person to another. For example, in a study of voter behavior in Boca Raton, an investigator might try to understand why residents voted for a Democrat or Republican candidate.

What Is an Independent Variable?

An independent variable is a variable that influences the dependent variable. Studies analyzing dependent variables look at how and why they differ from one another. Independent variables represent those factors that might influence the behavior under study. For example, in our study of voter behavior in Boca Raton, an investigator might try to analyze for the independent variable of age. Such a study would try to determine if the age of residents affected their voting preferences.

Creating a Hypothesis

A hypothesis is a statement that predicts the relationship between the dependent variable and the independent variable. Hypotheses are as specific as possible. The best hypotheses not only include how the independent variable affects the dependent variable, they also endeavor to predict why that influence takes place.

In the study of voters from Boca Raton, Florida, where the dependent variable is political party preference and the independent variable is age, a political scientist might create this hypothesis: Voters in Boca Raton are more likely to vote Republican if they're over the age of 65.

To evaluate a hypothesis, you can rewrite it in the form of a question: How likely is it that Boca Raton voters over 65 cast their ballots for the Republican candidate?

You can even get more specific and ask a question that results in a measurable answer: What percentage of Boca Raton voters over the age of 65 voted for the Republican candidate?