Research methods Flashcards
What is an experiment?
A research method in which the researcher tries to control all variables other than the independent variable and the dependent variable; this allows the researcher to identify a cause-and-effect relationship between the IV and the DV.
What is a hypothesis?
A testable statement about the relationship between two variables: The independent variable and the dependent variable.
What is the independent variable?
The factor which will be varied or changed in an experiment to look for an effect on the other variable.
What is the dependent variable?
It is the outcome or effect we are measuring within the study.
What is a null hypothesis?
A hypothesis that exists and states that no variables affect any other variables.
How do you write a null hypothesis?
There is not going to be a significant difference in the “dependent variable” between “condition a” and “condition B” of the “independent variable”.
What is an alternative hypothesis?
The hypothesis the researcher tests by conducting a study and collecting data, which attempts to show the null hypothesis is not supported.
How do you write an alternative hypothesis?
It is predicted that there will be a significant difference in the “dependent variable” between the two conditions of the “independent variable”.
What are the different experimental methods?
- Laboratory experiment.
- Field experiment.
- Natural experiment.
What is a laboratory experiment?
- There is a high level of control of extraneous variables.
- There is an IV which is manipulated by the researcher and causes a change in the DV.
- They take place in a controlled environment, often a laboratory
What are some advantages of a laboratory experiment?
- Easy to replicate, because it is possible to recreate the same environment and the same procedures. So we can check the reliability of the results
- Researcher has control over the variables, so we are able to conclude that the IV is the cause of the DV
What are some disadvantages of a laboratory experiment?
- The setting is artificial. They often lack ecological validity, as the behaviour studied does not represent real life conditions. The results cannot be generalised to the natural environment of participants
- Participants may display demand characteristics, which means that they understand the aim of the study and act accordingly
What is a field experiment?
- This is conducted in a real life setting – for example, a school, hospital or subway.
- Takes place where the behaviour would normally occur.
- The experimenter still manipulates the IV to see the effect on the DV.
What are some advantages of a field experiment?
- Behaviour is more natural than laboratory experiment, as it takes place in the natural environment, so we have higher ecological validity.
- The participants do not know they are being studied, so they act naturally
What are some disadvantages of a laboratory experiment?
- Deception – participants do not always know they are taking part in research.
- Extraneous variables cannot be controlled in the natural environment, so we cannot be sure that the IV is the cause of the DV
What is a natural experiment?
- This is where the independent variable changes naturally (on its own). It is not manipulated by the researcher.
- For example, the effects of stress on families due to the recent recession. An experimenter cannot create this situation, it has occurred naturally and so they can study the effects of the IV.
What are some advantages of a natural experiment?
- Allows researchers to study variables that could not be manipulated (eg, the effect of gender or age on behaviour).
- There is some control over extraneous variables, so it is possible to see how the IV affects the DV.
What are some disadvantages of a natural experiment?
- The environment can be artificial and so there might be low ecological validity.
- Participants might be aware that they are being studied, so their behaviour will not be natural
What is experimental design?
How the participants are used in the conditions of an experiment.
What are the different types of experimental design?
- Independent groups.
- Repeated measures.
- Matched pairs.
What are independent groups?
Where two or more separate groups of participants are used in an experiment; each member of the pair takes part in a different condition.
What are some advantages of independent groups?
- There are no order effects because people only take part in one condition.
- Often, the same material can be used for the task in both conditions.
- Participants cannot work out the aim of the study because they only take part in one condition.
What are some disadvantages of independent groups?
- There are different people(participant variables) and the two conditions so that may be why the results are different.
- You need more people for the study. To get 10 in each group you need 20 people.
What are repeated measures?
When only one group of participants is used in an experiment; this group takes part in both conditions.