Variables

Question 1

variable

Answer 1

A variable is something that can change or be changed (e.g., temperature, heart rate, and noise).

Question 2

Independent variable

Answer 2

The variable being manipulated, usually by the researcher.

Question 3

Dependent variable

Answer 3

The variable being influenced by the independent variable, which can be measured.

Question 4

Extraneous variable

Answer 4

A variable other than the IV which has influenced the DV and therefore threaten the accuracy of the results.

Question 5

Co-variables

Answer 5

Two variables which are examined to see whether a correlation exists between them.

Question 6

psychologists try to determine CAUSE and EFFECT in an experiment

Answer 6

This means trying to reduce extraneous variables to see how manipulation of the IV influences the participants’ behaviour, as measured by the DV. If an experiment is well controlled, then it can be concluded that changes in the IV CAUSED the EFFECT seen in the DV.

Question 7

Operationalisation of Variables

Answer 7

This means defining the variables clearly so that they can be objectively manipulated or measured.

Question 8

confounding variable

Answer 8

is a specific example of an extraneous variable. It is any variable other than the IV, that has had a constant impact on the DV. This means that the researcher cannot be sure what has caused any change in the DV. Researchers generally only discover confounding variables after an experiment has been conducted.

Question 9

types of extraneous/ confounding variable

Answer 9

participant variables
situational variables
demand characteristics
investigator effects
order effects

Question 10

Participant variables

Answer 10

are related to the participants involved; they are only an issue when different participants are used in each condition. For example, gender, age, intelligence, motivation, personality. Participant variables can be controlled by using a repeated measures design or a matched pairs design.

Question 11

Situational variables

Answer 11

are any extraneous/confounding variables related to the research situation that may influence participant behaviour. For example, temperature, noise, time of day. Most situational variables can be controlled through standardisation. Other examples of situational variables include …

Question 12

Demand characteristics

Answer 12

A specific example of an extraneous /confounding variable is known as demand characteristics. Participants are rarely passive in investigations. Demand characteristics can occur as participants are often very conscious of the fact, they are taking part in psychological research resulting in them being curious about what they are being asked to do. This might lead participants to look for cues about how they are expected to behave and produce behaviours which they think the researcher is demanding. Demand characteristics can be controlled by using a single blind design.

Question 13

Investigator effects

Answer 13

Another specific example of an extraneous /confounding variable is an investigator effect. This describes anything that a researcher does that has an effect on a participant’s performance in a study, other than what was intended. For example, in the way they communicate with the participants either verbally or non-verbally or in the way that a study is designed. Researchers might also be biased in their recording of data especially if they have an expectation about what results they expect to find. Investigator effects can be controlled through standardisation or random allocation.

Question 14

Order effects

Answer 14

Another possible extraneous/confounding variable is known as order effects. This refers to the order in which participants in complete conditions when a repeated measures design is used. Improved performance in the second condition could be due to practice. However, participants could do less well in the second condition due to boredom or fatigue. Order effects can be controlled by counterbalancing or randomisation.

Question 15

5 ways to control of Extraneous and Confounding Variables

Answer 15

standardisation
counterbalancing
randomisation
random allocation
single blind design

Question 16

standardisation

Answer 16

Most situational variables can be controlled through standardisation - by using a standardised procedure. This involves keeping everything (other than the IV) the same between conditions. For example, making sure that participants are given the same instructions in all conditions, using the same room and researcher for both conditions, etc.

Question 17

counterbalancing

Answer 17

One way to control for order effects is to use counterbalancing. If there are two conditions, half the participants complete condition A then B; the other half of the participants complete condition B then A.

Question 18

Randomisation

Answer 18

Another way to control for order effects which can be more useful if there are more than two conditions is randomisation. Here, participants all complete the conditions in a random order. This can be done by placing a number to represent each condition in a hat (e.g., 1-3 for three conditions). For each participant, the researcher selects one number from the hat which becomes the first condition the participant completes. The researcher selects a second number, and so on.

Question 19

Random allocation

Answer 19

This is a way of controlling for participant variables. Participants are allocated to each condition on a random basis which provides a random allocation of participants to conditions. It can also be used to control for investigator effects – to prevent the research from influencing which participants complete each condition.

Question 20

Single blind design

Answer 20

In a single blind design, participants are not made aware of the research aim or which experimental condition they have been placed in. This reduces the chances of them changing their behaviour to match what they think is expected of them (or the reverse!) – i.e., it reduces the risk of demand characteristics.