Introduction to Research Methods in Psychology

Three Main Types of Research in Psychology

There are many different ways to study the human mind and behavior, but psychology research can typically be classified as one of three major types: experimental, descriptive, or correlational.

1. Causal or Experimental Research

When most people think of scientific experimentation, research on cause and effect is probably what immediately comes to mind.

An example of this type of research in psychology would be changing the length of a specific mental health treatment and measuring the effect on study participants.

2. Descriptive Research

Descriptive research does exactly what the name implies—it describes. This type of research seeks to show what already exists in a group or population.

Three types of psychology research utilizing this method are:

• Case studies
• Observational studies
• Surveys

An example of this psychology research method would be an opinion poll to determine which presidential candidate people plan to vote for in the next election.

These types of studies are a type of qualitative research, which focuses on getting deep, rich, and descriptive data about behaviors and experiences. It often utilizes strategies like observations and interviews,

3. Relational or Correlational Research

Relational research, also known as correlational research, is a type of study that investigates the connection between two or more variables. These variables usually already exist in a population; the researchers just want to determine how they are related and the strength of that connection. 

Consider a study examining the ratio of men and women selecting either classical or jazz music. Here, the correlational study is exploring the link between gender and musical preference.

Theory vs. Hypothesis in Psychology Research

Understanding the different types of research is just one part of the process. Before a study begins, researchers need a clear idea of exactly what they are investigating. A theory can help provide a foundation for their research, while a hypothesis represents their specific guess about what might happen (or what will happen).

People often confuse the terms theory and hypothesis or are not quite sure of the distinctions between the two concepts. If you're a psychology student, it's essential to understand what each term means, how they differ, and how they're used in psychology research.

A theory is a well-established principle that has been developed to explain some aspects of the natural world. A theory arises from repeated observation and testing and incorporates facts, laws, predictions, and tested hypotheses that are widely accepted.

A hypothesis is a specific, testable prediction about what you expect to happen in your study. For example, an experiment designed to look at the relationship between study habits and test anxiety might have a hypothesis that states, "We predict that students with better study habits will suffer less test anxiety."

While the terms are sometimes used interchangeably in everyday use, the difference between a theory and a hypothesis is important when studying experimental design.

The Effect of Time on Research Methods in Psychology

Just as the type of research shapes how a study is carried out, time also plays a role in how data is collected and what it may mean. There are two types of time dimensions that can be used in designing a research study: cross-sectional and longitudinal.

Cross-Sectional Psychology Research

Cross-sectional research takes place at a single point in time. In this design, all tests, measures, or variables are administered to participants on one occasion. This type of research seeks to gather data on present conditions instead of looking at the effects of a variable over a period of time.

Longitudinal Psychology Research

Longitudinal research is a study that takes place over a period of time.
Data is first collected at the beginning of the study, and may then be gathered repeatedly throughout the length of the study.

Some longitudinal studies may occur over a short period of time, such as a few days, while others may take place over a period of months, years, or even decades.

Causal Relationships Between Psychology Research Variables

What do we mean when we talk about a “relationship” between variables? In psychological research, we're referring to a connection between two or more factors that we can measure or systematically vary.

One of the most important distinctions to make when discussing the relationship between variables is the meaning of causation.

Correlational Relationships Between Psychology Research Variables

To understand relationships between variables, researchers often explore how changes in one lead are related to changes in another using a statistic called a correlation.

• A positive correlation is a direct relationship where, as the amount of one variable increases, the amount of a second variable also increases.
• In a negative correlation, as the amount of one variable goes up, the levels of another variable go down.

In both types of correlation, there is no evidence or proof that changes in one variable cause changes in the other variable. A correlation simply indicates that there is a relationship between the two variables.