inferential statistics

Question 1

What is the sign test used for

Answer 1

To determined whether the significance we have found in our research is significant

Question 2

What must the researchers ensure so they can use the sign test

Answer 2

• Test of difference (to see if the scores increase or decrease)
• Repeated measures design
• Nominal data (can be organised into categories +,-,0)

Question 3

what is the accepted level of significance in psychology

and why

Answer 3

less than or equal to 0.05 or 5%

We need it to be less than 5% due to chance

It helps us strike a balance between a type 1 or type 2 error

Question 4

What is the
S
N
and critical value

Answer 4

S value - calculated value (+/-) less frequent sign
N value - number of participants - any 0s= N value
Critical value - From the table of critical values

Question 5

what type of tailed hypothesis is a directional and non directional

Answer 5

Directional - one tailed
non-directional - 2 tailed

Question 6

How do you tell if the results are significant

Answer 6

The S value must be less than or equal to critical value for the results to be significant

Question 7

What are the types of data/ Levels of measurement

Answer 7

Nominal
Ordinal
Interval

Question 8

What is Nominal data

What can you find with it

Answer 8

The total number of participants falling into various categories.
- Least sophisticated way of measuring data
- E.g. tall or short, Fat or thin

Can be used to calculate the mode

Question 9

What is ordinal data

What can you measure from it

Answer 9

The data consists of participants individual scores that can be placed in rank order E.g. Lowest to highest, satisfaction rankings
- It is measured on a scale of unequal intervals (people are subjective e.g. best and worst food)

Can be used to calculate the median

Question 10

What is interval data

What can be measured by it

Answer 10

Data that have fixed interval and use internationally recognised forms of measurement e.g. IQ test, Class height order by cms
- No true 0 point

Can be used to calculate the mean

Question 11

How do we work out what type of test we will be using
(3Ds)

Answer 11

• Test of difference
• Level of measurement (type of data)
• Design

Question 12

What are the different tests

Answer 12

• Sign test
• Chi-squared
• Wilcoxon
• Mann-Whitney
• Spearman’s rank
• Related t-test
• unrelated t-test
• Pearson’s

Question 13

What designs are (Related)
and what are the tests of related:
- Nominal data
- Ordinal data
- Interval data

Answer 13

Repeated measures and matched pairs

Nominal - Sign test
Ordinal - Wilcoxon
Interval - Related T-test

Question 14

What design is (unrelated)
and what are the tests of unrelated:
- Nominal data
- Ordinal data
- Interval data

Answer 14

Independent groups

Nominal - Chi-squared
Ordinal - Mann Whitney
Interval - U - related T

Question 15

What deign is (correlation)
and what are the tests for correlation:
- Nominal data
- Ordinal data
- Interval data

Answer 15

Association/relationships

Nominal - chi-squared
Ordinal - Spearman’s rank
Interval - Pearson’s

Question 16

What probability do we use to strike a balance between a type 1 and type 2 error

Answer 16

0.05/5%

Question 17

What is a type 1 error and when can it occur

IS NOT

Answer 17

When you reject the Null hypothesis when it should have been accepted/kept
- The researcher falsely claims significance

• Can occur when the probability is too high e.g. p<,10

Question 18

What is a type 2 error and when can it occur

NOT IS

Answer 18

When the Null hypothesis is accepted but should have been rejected
- The researcher falsely rejects significance
- Occurs in more strict situations e.g. p<, 0.01