Introduction to Research Methods Updated August 08, 2016 1 The Three Types of Psychology Research Psychology research can usually be classified as one of three major types: 1. Causal Research When most people think of scientific experimentation, research on causeand-effect is most often brought to mind. Experiments on causal relationships investigate the effect of one or more variables on one or more outcome variables. This type of research also determines if one variable causes another variable to occur or change. An example of this type of research would be altering the amount of a treatment and measuring the effect on study participants. 2. Descriptive Research Descriptive research seeks to depict what already exists in a group or population. An example of this type of research would be an opinion poll to determine which Presidential candidate people plan to vote for in the next election. Descriptive studies do not seek to measure the effect of a variable; they seek only to describe. 3. Relational Research A study that investigates the connection between two or more variables is considered relational research. The variables that are compared are generally already present in the group or population. For example, a study that looked at the proportion of males and females that would purchase either
a classical CD or a jazz CD would be studying the relationship between gender and music preference. 2 Theory and Hypothesis
A hypothesis is a testable prediction about what will happen in an experiment, as seen in the above example. Image: http://www.flickr.com/photos/phae/ People often confuse the terms theory and hypothesis or are not quite sure of the distinctions between the two concepts. As a psychology student, it is essential to understand what each term means, how they differ, and how they are used in psychology research. A theory is a well-established principle that has been developed to explain some aspect 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." Unless your study is exploratory in nature, your hypothesis should always explain what you expect to happen during the course of your experiment or research. While the terms are sometimes used interchangeably in everyday use, the difference between a theory and a hypothesis is important when studying experimental design. Some important distinctions to note include: A theory predicts events in general terms, while a hypothesis makes a specific prediction about a specified set of circumstances. A theory has been extensively tested and is generally accepted, while a hypothesis is a speculative guess that has yet to be tested.
3 Effect of Time in Psychology Research There are two types of time dimensions that can be used in designing a research study. 1. Cross-sectional research takes place at a single point in time. 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. 2. Longitudinal research is a study that takes place over a period of time. Data is first collected at the outset 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 decades. The effects of aging are often investigated using longitudinal research. 4 Causal Relationships Between Variables What do we mean when we talk about a relationship between variables? In psychological research, we are 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. A causal relationship is when one variable causes a change in another variable. These types of relationships are investigated by experimental
research in order to determine if changes in one variable actually result in changes in another variable. 5 Correlational Relationships Between Variables A correlation is the measurement of the relationship between two variables. These variables already occur in the group or population and are not controlled by the experimenter. 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. The most important concept to take from this is that correlation does not equal causation. Many popular media sources make the mistake of assuming that simply because two variables are related, a causal relationship exists. Further Reading: The Simple Experiment Correlational Studies Steps in Psychology Research The Simple Experiment How Researchers Find Cause-and-Effect Relationships
Hill Street Studios / Blend Images / Getty Images Updated February 14, 2016 A simple experimental design is one type of experiment that psychology researchers might use to look at causal relationships between variables. When researchers are trying to determine if changes in one variable lead to changes in another variable, they must perform experiments in order to establish a causal relationship. Other research methods (such as correlational studies) can be used to establish that a relationship between two variables exists, but an actual experiment is necessary to establish that changes in one variable lead to changes in another variable. Experiments can be extremely complex and include many different variables. However, one of the most basic methods is to use what is known as a simple experimental design.
What is a Simple Experiment? A simple experiment can establish cause-and-effect, so this type of study is often used to determine the effect of a treatment. For examples, researchers might want to determine if administering a certain type of medicine leads to an improvement of symptoms. In a simple experiment, study participants are randomly assigned to one of two groups. Generally, one group is the control group and receives no treatment, while the other group is the experimental group and receives the treatment. The Elements of a Simple Experiment The simple experiment is composed of a few key elements: The experimental hypothesis is a statement that predicts that the treatment will cause an effect. The experimental hypothesis will always be phrased as a cause-and-effect statement. For example, researchers might propose a hypothesis that: "Administration of Medicine A will result in a reduction of symptoms of Disease B." The null hypothesis is a hypothesis that the experimental treatment will have no effect on the participants or dependent variables. It is important to note that failing to find an effect of the treatment does not mean that there is no effect. The treatment might impact another variable that the researchers are not measuring in the current experiment. The independent variable is the treatment variable that is manipulated by the experimenter. The dependent variable is the response that the experimenter is
measuring. The control group is the group that is made up of individuals who are randomly assigned to a group but do not receive the treatment. The measures takes from the control group are then compared to those in the experimental group to determine if the treatment had an effect. The experimental group is the group that is made up of individuals who are randomly assigned to the group and then receive the treatment. The scores of these participants are compared to those in the control group to determine if the treatment had an effect. Determining the Results of a Simple Experiment Once the data from the simple experiment has been gathered, researchers then compare the results of the experimental group to those of the control group to determine if the treatment had an effect. How do researchers determine this effect? Due to the always present possibility of errors, we can never be 100 percent sure of the relationship between two variables. After all, there might always exist some unknown variables that we are unaware of or unable to measure that might nevertheless have an influence over the outcomes. Despite this ever-present problem, there are ways to determine if there most likely is a meaningful relationship. Experimenters use inferential statistics to determine if the results of an experiment are meaningful. Inferential statistics is a branch of science that deals with drawing inferences about a population based on measures taken from a representative sample of that population. The key to determining if a treatment had an effect is to measure the statistical significance. Statistical significance shows that the relationship between the variables is probably not due to mere chance and that a real relationship most likely exists between the two variables.
Statistical significance is often represented like this: p < 0.05 A p-value of less than.05 indicates if the particular results are due merely to chance, the probability of obtaining these results would be less than 5%. Occasionally, smaller p-values are seen such as p < 0.01. There are a number of different means of measuring statistical significance. The type of statistical test that is used depends largely on the type of research design that was used for the experiment. How Do Social Psychologists Conduct Research? Trina Dalziel / Getty Images Updated July 21, 2016 Social psychology research methods allow psychologists to get a better look at
what causes people to engage in certain behaviors in social situations. In order to empirically study social behavior, psychologists rely on a number of different scientific methods to conduct research on social psychology topics. These methods allow researchers to test hypotheses and theories and look for relationships between different variables. Why do people do the things they do? And why do they sometimes behave differently in groups? These questions are of interest not only to social psychologists, but to teachers, public policy-makers, healthcare administrators, or anyone who has ever watched a news story about a world event and wondered, Why do people act that way? Which type of research is best? This depends largely on the subject the researcher is exploring, the resources available, and the theory or hypothesis being investigated. Why Do Psychologists Study Social Behavior? Why study social behavior? Since so many "common sense" explanations exist for so many human actions, people sometimes fail to see the value in scientifically studying such behaviors. However, it is important to remember that folk wisdom can often be surprisingly inaccurate and that the scientific explanations behind a behavior can be quite shocking. Milgram's infamous obedience experiments are examples of how the results of an experiment can defy conventional wisdom. If you asked most people if they would obey an authority figure even if it meant going against their moral code or harming another individual, they would probably emphatically deny that they would ever do such a thing. Yet Milgram's results revealed that 65 percent of participants would hurt another person simply because they were told to do so by an authority figure. For such reasons, it is important to utilize the scientific method to study
psychological phenomena in an objective, empirical, and analytical way. By employing the scientific method, researchers can see cause-and-effect relationships and generalize the results of their experiments to larger populations. While common sense might tell us that opposites attract, that birds of a feather flock together, or that absence makes the heart grow fonder, psychologists can put such ideas to the test using various research methods to determine if there is any real truth to such folk wisdom. How Do Social Psychologists Use Descriptive Research? The goal of descriptive research is to portray what already exists in a group or population. One example of this type of research would be an opinion poll to find which political candidate people plan to vote for in an upcoming election. Unlike causal and relational studies, descriptive studies cannot determine if there is a relationship between two variables. They can only describe what exists within a given population. An example of descriptive research would be conducting a survey to find out people's attitudes toward a particular social issue such as divorce, capital punishment, or gambling laws. Common Types of Descriptive Research Some of the most commonly used forms of descriptive research utilized by social psychologists include: Surveys Surveys are probably one of the most frequently used types of descriptive research. Such surveys usually rely on self-report inventories in which people fill out questionnaires about their own behaviors or opinions. The advantage
of the survey method is that it allows social psychology researchers to gather a large amount of data relatively quickly, easily, and cheaply. The Observational Method This involves watching people and describing their behavior. Sometimes referred to as field observation, this can involve creating a scenario in a lab and then watching how people respond or performing naturalistic observation in the subject's own environment. Each type of observation has its own strengths and weaknesses. Researchers might prefer using observational methods in a lab in order to gain greater control over possible extraneous variables, while they might prefer using naturalistic observation in order to obtain greater ecological validity. However, lab observations tend to be more costly and difficult to implement than naturalistic observations. Case Studies A case study involves the in-depth observation of a single individual or group. Case studies can allow researchers to gain insight into things that are very rare or even impossible to reproduce in experimental settings. The case study of Genie, a young girl who was horrifically abused and deprived of learning language during the critical period, is one example of how a case study can allow social scientists to study a phenomena that they otherwise could not reproduce in a lab. How Do Social Psychologists Use Correlational Research? Social psychologists use correlational research to look for relationships between variables. For example, a social psychologist might carry out a correlational study looking at the relationship between media violence and aggression. He might collect data on how many hours of aggressive or violent television programs children watch each week and then gather data how on
aggressively the children act in lab situations or in naturalistic settings. Conducting surveys, directly observing behaviors, or compiling research from earlier studies are some of the methods used to gather data for correlational research. While this type of study can help determine if two variables have a relationship, it does not allow researchers to determine if one variable causes changes in another variable. While the researcher in the previous example on media aggression and violence can use the results of his study to determine if there might be a relationship between the two variables, he cannot say definitively that watching television violence causes aggressive behavior. How Do Social Psychologists Use Experimental Research? Experimental research is the key to uncovering causal relationships between variables. In experimental research, the experimenter randomly assigns participants to one of two groups: 1. The control group. The control group receives no treatment and serves as a baseline. 2. The experimental group. Researchers manipulate the levels of some independent variable in the experimental group and then measure the effects. Because researchers are able to control the independent variables, experimental research can be used to find causal relationships between variables. So if a psychologist wanted establish a causal relationship between media violence and aggressive behavior, he would want to design an experiment to test his hypothesis. If his hypothesis is that playing violent video games causes players to respond more aggressively in social situations, he would want to randomly assign participants to two groups. The control group would play a non-violent video game for a predetermined period of time while the experimental group would play a violent game for the same period of time.
Afterwards, the participants would be placed in a situation where they would play a game against another opponent. In this game, they could either respond aggressively or non-aggressively. The researchers would then collect data on how often people utilized aggressive responses in this situation and then compare this information with whether these individuals were in the control or experimental group. By using the scientific method, designing an experiment, collecting data, and analyzing the results, the researcher can then determine if there is a causal relationship between media violence and violent behavior. Why Social Research Methods Are So Important The study of human behavior is as complex as the behaviors themselves, which is why it is so important for social scientists to utilize empirical methods of selecting participants, collecting data, analyzing their findings, and reporting their results. Learn more about some of the different research methods that psychologists use to study human behavior: An Introduction to Psychology Research Methods 5 Steps That Every Psychology Experiment Should Follow How Are Variables Used in Psychology Research?