Statistical testing

Question 1

What are the three levels of measurement?

Answer 1

Nominal
Ordinal
Interval

Question 2

What is nominal data?

Answer 2

Named distinct categories E.G sex, eye colour

Question 3

What is ordinal data?

Answer 3

data that is ordered in some way, but the actual value of the figure isn’t measurable (doesn’t have a unit) E.G least to most aggressive

Question 4

What is interval data?

Answer 4

measured along. scale (has units) where the distance between one value and the next is equal and standardised E.G temperature

Question 5

What are the three factors used to decide which statistical test to use?

Answer 5

1. difference- test of difference or correlation
2. Design - independent groups (unrelated) , repeated measures or matched pairs (related)
3. data- nominal ordinal or interval

Question 6

what experimental designs are related?

Answer 6

Repeated measures and matched pairs

Question 7

what experimental designs are unrelated?

Answer 7

Independent groups

Question 8

What is the criteria for using a parametric test?

Answer 8

1. interval data
2. population is normally distributed
3. variance between two samples is not statistical significant

Question 9

Draw the table for choosing a statistical test

Answer 9

test of difference/correlation
unrelated design/ related design
Nominal- chi squared ,sign test, chi squared
ordinal- mann-whitney ,wilcoxon ,spearmans rho
interval- unrelated t-test, related t-test, Pearson’s r