2020 paper mistakes

Question 1

When data contains anomalies, which is best to use?

Answer 1

Median

Question 2

Which feature is needed to choose a test of statistical significance?

Answer 2

Level of data

Question 3

In the study by Levine et al. (2001) investigating cross cultural differences in helping behaviour, what level of data was recorded for the helping measure that involved responses to a dropped pen?

Answer 3

Nominal

Question 4

If the variance for a set of data is 16, what is the standard deviation?

Answer 4

4

Question 5

Write a one - tailed alternative hypothesis for this study

Answer 5

Less food (number of items eaten) will be consumed from the red plate compared to the white plate.

Question 6

One strength of repeated measures in the study

Answer 6

Likely answers: individual differences (participant variables) controlled for, fewer participants required

Question 7

One weakness of repeated measures in the study

Answer 7

Likely answers: order (or carry-over) effects a problem, increased risk of demand characteristics, fatigue

Question 8

Evaluate the external validity of this study.

Answer 8

External validity can refer to aspects of ecological validity and or population validity.

Question 9

Explain why the data for the rating of extroversion for participants (b) and (l) have both been given rank 6.5.

Answer 9

They both have the same extroversion rating (65), which in an ordered sequence of all the extroversion ratings occupy rank positions 6 and 7, so ranks 6 and 7 have been shared (added together and divided by two), resulting in a rank of 6.5 for both.

Question 10

Explain why it is more appropriate to use the mean, rather than the median, to calculate central tendency in this study.

Answer 10

The mean takes into account all of the data and is more mathematically accurate than the median which does not take into account all of the scores.

Question 11

Calculate the correlation coefficient for the data collected in this study using the formula for Spearman’s ranked correlation coefficient presented below. Show your workings.

Answer 11

Question 12

Outline two things that could have affected the validity of the data collected in this study.

Answer 12

Likely answers: demand characteristics affecting the accuracy of extroversion self-rating; honesty regarding salary details; problems interpreting extroversion rating scale etc