Control of variables / pilot studies

Question 1

What are extreanous variables?

Answer 1

Any variable other than the IV that may have an effect on the DV if it is not controlled.
* A researcher should try to identify them at the beginning of a study and attempt to minimise them
* Do not very systematically with IV

Question 2

How can extraneous variables be controlled?

Answer 2

• Random allocation
• Test all ppt in same room
• Ensure all ppt hear the same instructions
• Ensure all ppt tested by same researcher

Question 3

What are confounding variables?

Answer 3

• Any variable,other than the IV, that may affect the DV so we cannot be sure of the true source of changes to the DV
• Change systematically with IV

Question 4

What are demand characteristics?

Answer 4

Any cue from the researcher or from the research situation that may be interpreted by pt as revealing the purpose of investigation → amend behaviour
* May act in a way they believe the experimenter would want them to act
* May deliberately under play to sabotage the results

Question 5

What are investigator effects?

Answer 5

Any effects of researchers behaviour on the research outcome
* Researchers may unconsciously or consciously exhibit bias

Question 6

What is randomisation?

Answer 6

The use of of change in order to control for the effects of bias when designing materials and deciding the order of conditions

Question 7

What is counterbalancing?

Answer 7

Counterbalancing → PPT split into separate groups so half do A then B condition
Other half B then A
When put together and treat as one group again it will all balance out
* Compare the two results for the two conditions as usual
Not getting order effects / practice effect evened out

Question 8

What is standardisation?

Answer 8

Using the exact same formalised procedures for all participants within the study
* Increases reliability and ability for successful replication

Question 9

What is a pilot study?

Answer 9

A small scale trial run of an actual investigation.–> to allow modifications to be made

Allows researcher to identify any potential issues and to modify → saving long term money
Aim is to check
* Procedures
* Materials
* Measuring scales

Question 10

What is a single blind procedure?

Answer 10

participants will not be told the aims and not know what condition they are in

• an attempt to control confounding effects of demand characteristics

Question 11

What is a double blind procedure?

Answer 11

neither participants nor the researcher who conducted the study is aware of the aims

Question 12

What is a control group?

Answer 12

setting a baseline → used for purpose of comparison
* If the change in behaviour of the experimental group is greater than the control group we can conclude that the cause was the IV

Question 13

what are the ethical issues?

Answer 13

• Confidentiality
• Informed consent
• Deception
• Debriefing – clarify misunderstanding
• Right to withdrawal
• Protection from harm