Cognitive Data Analysis

Question 1

Strengths of mean

Answer 1

Most sensitive and powerful as it uses all the scores

Question 2

Weaknesses of mean

Answer 2

Extreme scores can skew the score - may not be representative

May not be an actual score (eg 0.5 of something that can’t be divided)

Question 3

Strengths of median

Answer 3

Not affected by extreme score

Question 4

Weaknesses of median

Answer 4

If there’s a small data set it may not be useful - may not give accurate representation

Can take a long time to figure out with large sets of data

Question 5

Strengths of mode

Answer 5

Easy to calculate

Can be used on non-numerical data

Question 6

Weaknesses of mode

Answer 6

If there are more than 2 modes it becomes meaningless

Question 7

Strengths of range

Answer 7

Easy to calculate

Question 8

Weaknesses of range

Answer 8

Can be affected by extreme scores

Does not tell us if the spread of data is normal or skewed

Question 9

Strengths of standard deviation

Answer 9

More accurate as it uses all scores

Question 10

Weaknesses of standard deviation

Answer 10

Hard to calculate manually

Question 11

What is the observed value?

Answer 11

The value that has been worked out from the ppts’ results that is compared to the critical value (on the table at front of paper)

Question 12

What is a Type 1 error?

Answer 12

If you reject the null hypothesis and it is actually true

Happens when the level of significance is too lenient

Question 13

What is a Type 2 error?

Answer 13

If you keep the null hypothesis when your experiment did work. (when there is a significant difference)

Happen when the level of significance is too harsh

Question 14

What level of probability do we start at?

Answer 14

p <= 0.05

The probability the results are due to chance is equal to or less than 5%

(unless we’re trying to disprove someone else’s results. Then we start at p <= 0.01)

Question 15

What are the 4 levels of measurement/types of data?

Answer 15

Nominal
Ordinal
Interval
Ratio

Question 16

What is Nominal data?

Answer 16

Most basic level of measurement

Used when data is put into tally charts/categories

Only tells us how many ppts picked each option

Doesn’t give an individual score for each ppts

Question 17

What is Ordinal data?

Answer 17

Used when data can be ordered eg 1st, 2nd, 3rd

Can’t tell the gap between 1st and 2nd etc

Always used with questionnaires

Gives us an individual score for each ppts

Question 18

What is Interval data?

Answer 18

The distance between each score has a meaning and equal value.
eg gap between 5-10cm is same as 20-25cm

0 is just another number on the scale, it does not mean there is nothing
eg 0 degrees c doesn’t mean there’s no temperature

Question 19

What is Ratio data?

Answer 19

The distance between each score has meaning and an equal value.

However, 0 does mean nothing.
eg 0 seconds to do something means it took no time

Question 20

Which test should you use? :
It is NOT an experiment
It uses ORDINAL data

Answer 20

Spearman’s Rho

Question 21

Which test should you use? :
It is an experiment
It uses REPEATED MEASURES
It uses ORDINAL data

Answer 21

Wilcoxon Test

Question 22

Which test should you use? :
It is an experiment
It uses INDEPENDANT GROUPS
It uses ORDINAL data

Answer 22

Mann Whitney U Test

Question 23

Which test should you use? :
It is an experiment
It uses INDEPENDANT GROUPS
It uses NOMINAL data

Answer 23

Chi Square