Interpreting inferential statistics

Question 1

What is nominal level data?

Answer 1

Data put into categories with no numerical value

Question 2

What is an example of nominal level data?

Answer 2

If you surveyed people on their favourite pet, you would get tallies in categories of the different types of pets

Question 3

What is ordinal level data?

Answer 3

A score on a scale but the number represents rank position

Question 4

What is an example of ordinal level data?

Answer 4

The position of football teams in a league

Question 5

How can interval/ratio level data be turned into ordinal data?

Answer 5

By putting scores in rank order

Question 6

What is interval level data?

Answer 6

Data that is assigned a numerical value but doesn’t have an absolute zero

Question 7

What is an example of interval level data?

Answer 7

Temperature readings as temperature can be less than 0

Question 8

What is ratio level data?

Answer 8

Data that is assigned a numerical value however there is a value of absolute 0

Question 9

What is an example of ratio level data?

Answer 9

Measure of height - you can’t have a negative value of height

Question 10

Why are inferential statistics used?

Answer 10

To show whether a result is due to chance or due to manipulation of the IV

Question 11

What are the conditions for which to use a Wilcoxon signed ranks test?

Answer 11

• Test of difference
• Repeated measures or matched pairs design
• Ordinal level data

Question 12

What are the conditions for which to use a Mann-Whitney U-test?

Answer 12

• Test of difference
• Independent groups design
• Ordinal level data

Question 13

What is an observed (or calculated) value?

Answer 13

The number / value produced after applying a inferential test formula

Question 14

What is a critical value?

Answer 14

The number / value that must be achieved in order for a result to be significant

Question 15

In inferential statistics we calculate the ________ value and compare it to the ________ value

Answer 15

• Observed
• Critical

Question 16

What is the level of significance psychologists typically use?

Answer 16

p ≤ 0.05

Question 17

What does p ≤ 0.05 mean in an experiment?

Answer 17

5% due to chance - not associated with the IV
95% due to manipulation of the IV

Question 18

What is a type I error?

Answer 18

When a researcher accepts the alternate hypothesis and rejects the null hypothesis that is true

False positive

Question 19

When does a type I error usually occur?

Answer 19

When the level of significance is too lenient

Question 20

What is a type II error?

Answer 20

When a researcher rejects the alternate hypothesis and accepts the null hypothesis that isn’t true

False negative

Question 21

When does a type II error usually occur?

Answer 21

When the level of significance is too stringent