Experimental Design

Question 1

explain independent groups?

Answer 1

• two separate groups of pp’s experience 2 different conditions of an experiment
• if there are 2 levels of IV then all pp’s will experience 1 level of the IV
• group A= energy drink
• group B= water
• performance of both groups is compared

Question 2

explain repeated measures?

Answer 2

• all pp’s experience both conditions
• group A (1group)= first energy drink then water (CC)
• two sets of data would be compared to see if there was a difference
• guarantees the comparing of the same people in 2 separate conditions

Question 3

explain matched pairs?

Answer 3

• pp’s are paired together based on variables of their experiment
• eg. memory pp may be paired on the IQ
• one will be placed in condition A and the other in condition B
• then compare their results

Question 4

evaluate independent groups?

Answer 4

-pp’s are different and are in different groups
-if researcher finds difference in DV this may be due to individual differences
-researchers may use random allocation to combat this
+order effects however are not a problem but are for repeated measures as pp’s are less likely to guess the aims in IG.

Question 5

evaluate repeated measures?

Answer 5

-order effects: pp’s could get bored= fatigue effect: a decrease in performance of a task due to repetition and tired or performance effect
-pp’s may work out aims of study= demand characteristics
+pp variables controlled
+fewer pp’s needed

Question 6

evaluate matched pairs?

Answer 6

+due to one condition, order effects and demand characteristics are lessened which is an improvement on repeated measures

• pp’s can never be matched EXACTLY,will still have differences on the DV
• matching is time consuming+expensive