♥Psychological Investigations| Experiments| Key Terms♥

Hi all,

In the psychological investigation topic of Experiments there are a few Key Terms that are important for your understanding of the topic; so i will discuss them here and give you examples of what you could write for questions on these questions.

Types of Experiments

Lab Experiments- these usually take place in a highly controlled environment such as a Laboratory clearly stated by the name. Such experiments provide the researcher with high levels of control over variables however such studies do not have high ecological validity. Usually such questions are asked about the strengths and weaknesses of lab experiments ( there is a blog post on this here so you would state a weakness and a strengths and give examples for each.)

Field Experiments - These take place in the natural environment of participants however the experimenter still has some control over variables. such experiments allow to see participants natural behaviour to a certain extent however these don't give the experimenter the levels of control that are available with the lab experiments . Once again if a question is asked on Field experiments i have written a blog post here explaining all the pro's and cons of it.

Quasi Experiments are like a 'mini-experiment' of the actual study to see if the hypothesis and everything is tested and if the experimental design, participant group is working. If you think about a TV series such as Vampire Diaries or American Horror story the first episode of any series is called pilot and this is because this is seeing whether people will be interested in continuing to watch this tv programme so referring back to psychology our quasi ( it is sometimes referred to as pilot ) study is like our Pilot episode of a series of experiments.

Types of Variables

Independent Variable- This is something that the researcher manipulates

Dependent Variable is something that the researcher measures

Confounding Variables are variables which could possibly affect the dependent variables however the experimenter has some control over those  a bit like a lab where there's windows and the weather outside is rain and wind then the participants could be distracted by the events wearing outside however the researcher could if there was blinds in the experimenting room, pull them down.

Extraneous Variables are variables which could possibly affect the DV however the researcher has no control over what happens. For example if researchers where doing a study about participants levels of anxiety created by a historical events such as WW2 through viewing some images of things such as images of concentration camps, some participants may have had relatives that may have been involved in the war directly which could effect the results.

How to make sure that Your Experiment is reliable?

This is often an exam question which looks a bit like ; How can the experimenter make sure research is reliable? This is possible through replication of your study. The way your study can be replicated is if you carry it out in different areas of the city/ country and check whether there is a pattern in the trends. And also through publishing your study and allowing other psychologist to see whether your experiment works. This is made possible by writing a good procedure which is something i will be writing a blog on next.

What is Ecological Validity?

This is a term used by psychologist to explain to what extend the study/experiment/research is true to life. These can be shown by Natural Experiments which are most true to life in comparison to ones such as lab experiments.

Experimental Design

summaries of the three types of  experiments can be found here and im going to talk you through some limitations here. In Repeated measures design the participants may be subjected to Order effects this si because the same participants may go through the same condition more than once the experiments results may be influenced by actions in previous events of the condition. In Independent  Measures design the results may be created by individual differences, for example if you're doing a a study on  memory every one has a different memory capacity to others so therefore some people may be able to remember more so than others. There is also another experimental design called Counter Balancing and this is where you control effects of extraneous variables by making sure you keep all of the variables equal,. Demand Characteristics can occur in any experiment , study observation and this is where the participants think they have identified what the objective of the study is and therefore tried to behave according to what they think may have affected the study.