experimental designs

Question 1

experimental design

Answer 1

this refers to the different ways in which the testing of participants can be organised in relation to the experimental conditions

Question 2

repeated measures

Answer 2

all participants experience both conditions of the experiment, so each participant would first experience conditions A, the participants would then later be tested in condition B, following this the data from both conditions would be compared to see if there is difference

Question 3

independent groups

Answer 3

this is where two separate groups of participant’s experience two different conditions of the experiment, this means that all participants experience on level of the IV. one group of participants take part in condition A and a different group of participants take part in condition B. then the results would be compared to see if there is a difference

Question 4

matched pairs

Answer 4

pairs of participants are first matched on a variable that may affect the DV, eg in a memory study participants may be matched on IQ as this may be a good indicator of their ability to recall information

Question 5

order effects

Answer 5

this is a confounding variable arising from the order in which conditions are presented

• this arises because repeating two tasks could cause boredom or fatigue that may cause deterioration in performance on the second task
• the participant’s performance may improve through the effects of practice, especially on a skill based task, in this case they would perform better on the second task

Question 6

participant variables

Answer 6

characteristics of an individual, such as age and intelligence, that may have affected the DV (confounding variable)

Question 7

repeated measures strength

Answer 7

participants performances are not affected by participant variables as they take part in both conditions of the experiment

Question 8

repeated measures limitation

Answer 8

participants performances are likely to be affected by order effects as they experience both conditions of the iv
it is also more likely the participants will work out the aim of the study when they experience all conditions of the experiment

Question 9

independent groups strength

Answer 9

participants performances are not affected by order effects as they only experience one condition of the iv
demand characteristics are less likely as participants are only aware of their own condition, the participants are also always naive to the task

Question 10

independent groups limitation

Answer 10

the biggest issue with an independent groups design is that the participants occupying the different groups are not the same, if a researcher finds a difference between the groups on the DV this may be more to do with participant variables than the effects of the IV

Question 11

matched pairs strengths

Answer 11

participants only take part in a single condition so order effects and demand characteristics are less of a problem
this is an attempt to control for the confounding variable of participant variables by matching participants on a key variable that may affect the DV

Question 12

matched pairs limitations

Answer 12

participants are only matched on one key variable there are many participant variables that aren’t controlled for that may affect the DV

Question 13

counterbalancing

Answer 13

controls the impact of order effects in a repeated measures design. half of the participant’s experience conditions in the order AB and the other half in the opposite order, BA. This allows order effects to be distributed evenly across both conditions, making each condition of the IV occur as the first task and second task equally