Experiments

What is an independent variable?

A factor that the researcher thinks might affect people’s behaviour. A cause of behaviour. For e.g, being labelled positively by your teacher.

What is a dependent variable?

The change in people’s behaviour that is a result of the IV. For e.g. improving your grades as a result of being labelled positively.

What is an extraneous variable?

Anything apart from the independent variable that could change the participants behaviour. For e.g. you might have hired a tutor at the same time as when your school teacher labelled you- so you can’t say grades improved because of labelling.

What is a cuasal relationship?

A cuasal relationship occurs when the IV causes a change in the DV- factor x makes factor y happen.

What is an experiment?

To see if a hypothesis is true or false, the researcher tests an independent variable to see if it has an effect on the dependent variable. A researcher will try and stop extraneous variables from having an effect. If the IV effects the DV a cause and effect relationship has been found. Sometimes researchers will find a correlation but not a cause and effect relationship.

What is a lab experiment?

This takes place in a setting the researcher can control. E.g. a room hired by a teacher. This has a standardised procedure and is more reliable but harder to replicate. Positivist (prefer the scientific method of research) theorists prefer this to field experiments.

What is a field experiment?

This takes places in a real life setting. This has higher validity and more chance of extraneous variables occurring. Interpretivist theorists prefer this to lab experiments as it is more valid and representative of human thoughts and feelings.

Field experiments are hard to replicate and have low validity

Natural school environments constantly change. Different schools have different teachers, behaviour policies, pupil cultures, and resources, making exact replication difficult. This reduces the scientific reliability valued by positivists.

Field experiments are high in validity

Field experiments take place in real educational settings such as classrooms or schools, based on "natural" teacher-pupil interactions that would be impossible to replicate in a lab. Manipulating an independent variable (e.g. telling teachers that some students have scored highly in an IQ test to see if this effects future grades) will then take place amongst normal classroom dynamics. Consequently, any effect on pupils is likely to be one that would occur in a real situation, leading to a high level of validity

What is an advantage of lab experiments?

Researcher has control over variables. The IV can be manipulated without any EV affecting the results. This means the researcher can be sure that changes in participants behaviour are because of the IV and nothing else. For example, in Milgram’s experiment the IV which was the change in the participants behaviour to electrocute the learner changed depending on the researcher’s guidance or the learner’s screams that were fake. Extraneous variables were controlled as only the authority figure and the participant were in the room.

What is another advantage of lab experiments?

Quantitative data is gathered about the IV and DV (participants behaviour) which means it is possible to see if there is a cause and effect relationship or correlation. For example, Bandura’s experiment measured levels of aggression- hitting the doll or verbally attacking the doll.

What is a disadvantage of lab experiments?

Lab experiments use small samples- if the sample is unrepresentative this means the results are not generalisable. We cannot be sure that the behaviour of the participants is typical of the wider population. For e.g. in Milgram’s study, the participants volunteered to be a part of the study so this is not representative of the wider population and how they would’ve acted when given an order to administer electric shocks to the learner.