9. Variables

Question 1

What is a variable

Answer 1

• A variable is a quantity whose value can change.
  For eg, time taken to do a task, someone’s anxiety level.
• In an experiment, there are various different kinds of variable. Some are manipulated by the researcher, others arent.

Question 2

What is the Independent variable

Answer 2

• An IV is a variable directly manipulated by the researcher**. (Variable that is changed)

Question 3

What is the Dependent variable

Answer 3

• The DV is the variable that is measured/will be affected by the changes in the IV.

Question 4

What is an Extraneous variable

Answer 4

• Ideally, in a study the only thing that would influence the DV would be the IV. Usually though, there are other things that will have an effect.
• An extraneous variable is any variable, other than the IV, that COULD affect the DV (what you’re measuring).
• If these things ARE actually influencing the DV, then they’re called confounding variables.

Question 5

What is Operationalisation

Answer 5

• Variables must be operationalised. This means describing the process by which the variable is measured.
• Allows others to see exactly how youre going to define & measure your variables (IV and DV).
• Some things are easy to operationalise (eg. height might be operationalised as ‘distance in cm from bottom of an object to the top). Other things are difficult to operationalise (eg. a mother’s love for her baby).

Question 6

How can Extraneous variables be controlled

Answer 6

• Extraneous variables can be controlled in a study so that theyre kept constant for all participants (eg. everyone could do task in same place so distractions are similar).
• Can ALSO be eliminated altogether (eg. everyone could do task somewhere w no noise distractions).

Question 7

4 ways of controlling research to avoid effects of extraneous variables

Answer 7

1. Counterbalancing
2. Random allocation
3. Standardisation
4. Randomisation

Question 8

What is Counterbalancing

Answer 8

• Mixing up the order of the tasks can solve order effects in repeated measures designs.
• Half of P’s do task with an audience first & then without. The others do the conditions the other way round. Any order effects would then be equal across conditions.

Question 9

What is Random allocation

Answer 9

• Eg. by drawing names out of a hat. Means everyone has an equal chance of doing either condition.
• An independent measures study with, for eg, more men in 1 group than the other could have a confounding variable. Any difference in performance may be due to sex rather than the real IV.
• Random allocation should ensure groups are not biased on key variables.

Question 10

What is Standardisation

Answer 10

• Should ensure the experimenters act in a similar way w all participants.
• Everything should be as similar as possible for all the P’s, including each P’s experience in such studies.
• Involves using exactly the same formalised procedures & instructions for all P’s.

Question 11

What is Randomisation

Answer 11

• When the material is presented to the P’s in a random order.
• Avoids possibility of order effects.
• For eg, in a repeated measures memory experiment, P’s may be asked to learn a list of words in 2 diff conditions. In each condition, the words on their lists would be in a random order.