Research Methods

Question 1

What are the 3 types of experimental designs

Answer 1

• Independent groups
• repeated measures
• matched participant

Question 2

What are the 4 inferential statistical tests

Answer 2

• chi square: difference, nominal data, independent group
• spearman’s rank: correlation, ordinal data, repeated measures
• Mann Whitney U: difference, interval/ratio data, independent groups
• Wilcoxon: difference, ordinal data, repeated measures design

Question 3

Strengths and weaknesses of a lab experiment

Answer 3

• strength: easy to replicate because of controls
• weakness: low ecological validity

Question 4

Strengths and weaknesses of natural experiments

Answer 4

• strength: high ecological validity
• weakness: no control over confounding variables

Question 5

Strengths and weaknesses of field experiment

Answer 5

• strength: high ecological validity
• weakness: not reliable

Question 6

Aim and hypothesis of our study

Answer 6

• aim: to test the effect of the acoustic similarity of words on short term memory
• experimental hypothesis: participants would recall a higher amount of words out of 10 in the acoustically dissimilar list of words (one tailed)
• null hypothesis: there is no difference in the number of words recalled in either condition and any difference found is due to chance

Question 7

Variables in our study

Answer 7

• IV: the list of words that is given to participants
• DV: each participants score of a recall test of 10 words

Question 8

Descriptive statistics for our study

Answer 8

• mean amount of words recalled out of 10 (list A) : 5.8/10
• mean amount of words recalled out of 10 (list B) : 5.6/10

Question 9

Mann Whitney U test for out study

Answer 9

• the critical value was 27 and the value of U was 45.5 which is greater than the critical value and therefore we have to accept the null hypothesis

Question 10

Strengths and weaknesses of independent groups design

Answer 10

• strength: there are no order effects so there’s a lower risk of demand characteristics
• weakness: there will be more participants required

Question 11

Strengths and weaknesses of repeated measures design

Answer 11

• strength: there is less participants required
• weakness: there are order effects so there is a higher risk of demand characteristics

Question 12

Strengths and weaknesses of matched pairs design

Answer 12

• strength: reduces participant variables because the each condition has people with similar characteristics
• weakness: time consuming trying to find closely matched pairs

Question 13

Features of a normal distribution curve

Answer 13

• bell shaped curve
• mode and median in the same place