Inferential Statistics/maths

Question 1

Test used with nominal data, independent measures design

Answer 1

Chi square

Question 2

Test with ordinal data and independent measures design

Answer 2

Mann-Whitney U-test

Question 3

Test with nominal data and repeated measures/matched participants

Answer 3

Binomial sign test

Question 4

Test using ordinal data and repeated measures/matched participants design

Answer 4

Wilcoxon signed ranks

Question 5

Test used ordinal data correlation study

Answer 5

Spearman’s Rho

Question 6

Test used interval/ratio correlation study

Answer 6

Pearson’s product moment

Question 7

Para and non parametric tests

Answer 7

Parametric tests are used when there is:
Interval/ratio level data (t tests and Pearson’s product moment)
A normal distribution of data
Similar variances between results from the different conditions (homogeneity of variance)

Question 8

First step chi square

Answer 8

Add up row and column totals and overall totals

Question 9

Second step chi square

Answer 9

Write in the observed frequency

Question 10

Step 3 chi square

Answer 10

Work out expected frequency

Row total X column total divided by overall total

Question 11

Fourth step chi square

Answer 11

Observed frequency minus expected frequency

Question 12

Fifth step chi square

Answer 12

Square the observed frequency minus expected

Question 13

Sixth step chi square

Answer 13

After you square the observed-expected

You divide this answer by the expected frequency

Question 14

Seventh step chi square

Answer 14

X squared = add up last column

Last column was where you divide by the expected frequency

Question 15

Chi square: X squared from the table is…

Answer 15

Calculated value

Question 16

Chi square: how to calculate degrees of freedom

Answer 16

(Number of rows-1) X (number of columns-1)

Always 1

Question 17

Chi square: how do you find critical value on the table

Answer 17

Look at level of significance needed at the top (columns)

Look at degrees of freedom at the side (rows)

Question 18

For chi square and Spearman’s Rho, what’s needed to be significant? (Confirm alternative hypothesis)

Answer 18

Calculated value bigger than critical value

Question 19

Binomial sign text what’s needed to show significant difference? (Confirm alternative hypothesis)

Answer 19

Critical must be bigger than calculated value

Question 20

Measures of dispersion

Answer 20

Range, variance, standard deviation

Question 21

Variance method

Answer 21

1. Calculate mean
2. Original score - mean (gives ‘d’ difference)
3. Square it (d2)
4. Add all new d squared values and divide by number of participants minus 1
   (Like mean but minus one from number of participants before you divide)

Question 22

Standard deviation method

Answer 22

Square root of variance

Question 23

Difference between bar graph and histogram

Answer 23

Gaps in bar charts (non continuous data)
Histogram used with interval/ratio data

Histogram Y axis frequency density 
Frequency density= frequency/ class width 

Frequency given by area of the bar, not height in histogram
Bar charts bars can be unrepresentative especially in unequal categories

Question 24

Binomial sign test method

Answer 24

1. Put plus or minus indication direction of difference
2. Add up least frequent sign to get calculated value
3. Use level of significance+one/two tailed hypothesis (column) and number of participants (rows) to find critical value
4. To show level of significance (confirm hypothesis) critical value must be bigger than calculated value

Question 25

Experiment hypothesis v correlation hypothesis language

Answer 25

Experiment ‘difference’

Correlation ‘relationship’

Question 26

Strength of variance

Answer 26

Takes into account all data collected

Question 27

Histogram eval

Answer 27

S- representative as shows correct proportions

Question 28

Bar chart eval

Answer 28

W- unrepresentative bars don’t always show correct proportions

Question 29

How to work out frequency density for histogram

Answer 29

Frequency divided by class width 
(This is how tall bar will be)

Question 30

What needs to be included for statement of significance

Answer 30

• Operationalised hypothesis
• level of significance (eg. P smaller or equal to 0.05)
• explain why (is calc value higher or lower than critical)

Question 31

Find ratios of given amount

Eg. 2:7 of £45

Answer 31

Divide value by total rations 
Multiply by ration you want to find out 
Eg. 45/9 = 5 
5 X 7 = 35 
5 X 2 = 10

Question 32

Find fraction of given amount

Answer 32

Divide by denominator

Multiply by numerator

Question 33

Pie chart

Answer 33

Data for each group divided by total data
X 360
= each sector

Question 34

Conversion between %, fractions & decimals

Answer 34

% into decimal = divide by 100

% into fraction = over 100 then simplest form