3 minute read
Experimental Psychology
There are some research studies that can involve a more structured observation setting. Later on, you will hear about the Strange Situation study done on infants and attachment. In the study, the infants were observed after putting them in a specific situation involving their mother and a stranger. It was designed to assess the child s attachment style with their mother. Like all observational studies, there is a risk of observer bias in which the observer looks only for specific things and not others. Another risk is that of a lack of inter-rater reliability, which can be eliminated by using the same observer for the entire study.
i
Advertisement
EXPERIMENTAL PSYCHOLOGY
Experimental psychology studies have the ability to look at cause and effect. Many different aspects of psychology can be looked at with these types of studies. If you ll remember, it was Wilhelm Wundt who first used these types of experiments in the 1870s. It is the preferred type of study used by researchers in behavioral psychology.
There are important things to understand about this type of research study. The first is the concept of empiricism. This means that the study must be based on things that are directly observable. In addition, all theories must be testable, which means they must be proven to be true or false. Another concept in this type of research is determinism. This means that there will always be some type of cause and effect. There should also be parsimony or simplicity, meaning that the simplest explanation for something is generally preferred.
There are several types of experiments that can be performed. A crucial experiment is one in which there are several hypotheses tested at the same time with the idea that one of them will be confirmed, while the others are rejected. A pilot study is sometimes done initially in order to look for potential weaknesses in the study design and to optimize future experimentation. A field experiment is done outside of a laboratory in a more natural setting.
You need to know the concepts of reliability and validity. Reliability means that the observation in the study is repeatable and consistent from time to time. This is why
subjects are often observed more than one time in order to make sure the results are always the same.
Validity refers to the accuracy of the conclusions that can be made from the study. It depends on whether or not the observations are reliable. With internal validity, there are no extraneous influences on the outcome. External validity refers to the ability to generalize the conclusion of the study. Construct validity refers to whether or not the abstract principles of the hypothesis translate to observable variables. Conceptual validity is similar but refers to whether the research relates well to the theory it was supposed to test.
In an experiment, there needs to be certain ways to make measurements. In nominal measurement, the numbers themselves don t really mean anything but are used to label things. Letters would otherwise do just as well. In ordinal measurement, the different pieces of data are ranked according to which things rank first, which things rank second, etcetera. Interval measurement measures the exact difference between to data points. Ratio measurement determines the ratio between sets of data points.
There are different types of research designs in experimental research. In one-way designs, there is just one independent variable. Such a design is used with an experimental group and a control group, which is the simplest design possible. Factorial designs involve multiple independent variables. Sometimes the variables are linked.
There are some major areas of psychology that use experimental methods of research. One of these is cognitive psychology. Remember that this studies things like learning, attention, problem solving, and memory. These can be studied in a laboratory setting. Because these things do not always involve observable behavior, functional magnetic resonance imaging or positron emission tomography can be used to map areas of the brain responsible for the processes observed.
Sensation and perception are often studied with experimental psychology. Stimuli can include things related to hearing, smell, taste, proprioception, vision and touch. There are ways to measure slight differences in the perception of these things that can be used to perform the experiment.