Experimental Methods :)

Question 1

What are the steps to designing a TRUE experiment? (4)

Answer 1

• decide sampling method
• operationalise variables
• choose experimental design
• control variables

Question 2

Define demand characteristics.

Answer 2

participants’ behaviours/responses affected by their interpretations of the study’s purpose based on cues

Question 3

Define experimenter effects.

Answer 3

participants’ behaviours/responses affected by cues (unknowingly) given by the experimenter

Question 4

What are the types of experimental blinding?

Answer 4

single-blind, double-blind

Question 5

Define single-blind. How frequently is this used?

Answer 5

participants don’t know which condition they’re in; almost always used

Question 6

Define double-blind. How frequently is this used?

Answer 6

participants and experimenter don’t know which condition they’re in; rarely used

Question 7

What’s the difference between probability and non-probability sampling?

Answer 7

whether you can specify the probability of an individual being selected

Question 8

What is the advantage of probability sampling (and thus the disadvantage of non-probability sampling)?

Answer 8

can ensure the sample is representative –> high external validity; generalisable

Question 9

random sampling

Answer 9

equal chance of being picked

Question 10

What is the main disadvantage of random sampling?

Answer 10

impractical (we rarely have access to everyone in the population)

Question 11

convenience sampling

Answer 11

whoever is readily available

Question 12

What is the disadvantage of convenience sampling?

Answer 12

unequal probability of being selected - prone to bias

Question 13

What are the variations of convenience sampling?

Answer 13

quota sampling; referral/snowball sampling

Question 14

quota sampling

Answer 14

sample people with specific traits until you have enough in each category

Question 15

referral/snowball sampling

Answer 15

ask participants to refer others with similar traits

Question 16

When is referral/snowball sampling most common?

Answer 16

qualitative research; niche population

Question 17

What is the issue with sampling bias?

Answer 17

not representative –> threatens external validity –> limits generalisability

Question 18

What are some types of sampling bias?

Answer 18

self-selection (volunteering); non-response

Question 19

What are between-participants designs (A.K.A. independent measures)?

Answer 19

different people in each condition

Question 20

What are within-participants designs (A.K.A. repeated measures)?

Answer 20

same people in each condition

Question 21

What is the disadvantage of between-participants designs (and thus the advantage of within-participants designs)? How is this dealt with?

Answer 21

individual differences may cause bias; random allocation

Question 22

What is the disadvantage of within-participants designs (and thus the advantage of between-participants designs)? How is this dealt with?

Answer 22

order effects; counterbalancing

Question 23

order effects

Answer 23

order of conditions affects results

Question 24

counterbalancing

Answer 24

different participants do conditions in different orders

Question 25

What are the types of order effects?

Answer 25

carry-over effects: practice effects, fatigue effects

Question 26

carry-over effects

Answer 26

the effect of being in one condition influences behaviour in another

Question 27

practice effects

Answer 27

performance in the later condition increases due to practice in the previous condition

Question 28

fatigue effects

Answer 28

performance in the later condition decreases due to fatigue from the previous condition

Question 29

What are the features of mixed designs?

Answer 29

- 2+ predictor variables - at least 1 is between-participants, at least 1 is within-participants

Question 30

How can you increase the trustworthiness of your (published) research?

Answer 30

transparency - openly acknowledging limitations