experimental designs

Question 1

define experimental design

Answer 1

the different ways in which participants can be organized in relation to the conditions in an experiment

Question 2

name the 3 experimental designs

Answer 2

independent groups, repeated measures, matched pairs

Question 3

define independent groups

Answer 3

participants are allocated to different groups where each group represents one experimental condition e.g condition A & condition B one is the control group to compare too and the other is experimental group

Question 4

strength of independent groups

Answer 4

order effects is not a problem- when participants are tested twice the order that they do the conditions in may effect results but in independent groups there is no order effects because of the two different conditions

Question 5

weakness of independent groups

Answer 5

the differences between the two groups can cause an EV, the difference in behavior may be due to participant variables rather than the change in the IV which acts as EV and reduces validity

Question 6

define allocation to conditions

Answer 6

participant variables can be dealt with using an unbiased method of allocation to conditions. random allocation is an unbiased method used to control for participant variables, if random methods are used this ensures that each participant has equal chance of being in one group as any other

Question 7

define control group

Answer 7

a group of participants who receive no treatment, their behavior acts as a baseline against which the effect of the IV may be measured

Question 8

define repeated measures

Answer 8

when all participants take part in all the conditions of the experiment

Question 9

strength of repeated measures

Answer 9

problem of participant variables is removed- each participant is compared to themselves rather than other people, fewer participants needed

Question 10

weaknesses of repeated measures

Answer 10

order effects because participants are tested twice the order they do the tasks may make a difference if they do the activity twice the second attempt may be better cus of practice this is the practice effect and it acts as an EV and is likely to reduce validity of results

Question 11

define counterbalancing

Answer 11

used in repeated measures designs to control for order effects, half of the participants complete the conditions in one order and the other half in the opposite order

Question 12

define control condition

Answer 12

the condition in a repeated measures design that provides a baseline measure of behavior without the experimental treatment (IV)

Question 13

define matched pairs

Answer 13

pairs of participants are matched in terms of variables relevant to the study, such as age or IQ, one member of each pair takes part in condition A of the experiment and the other takes part in condition B

Question 14

strength of matched pairs

Answer 14

doesnt deal with order effects because the participants are tested once, matched on a variable important to the experiment so partly solves the problem of participant variables

Question 15

weakness of matched pairs

Answer 15

Time-consuming to find suitable pairs.
Hard to perfectly match participants.
lots of effort for little gain