Intro to statistics

Question 1

What are the 2 main types of data?

Answer 1

Nominal (qualitative)

Ordinal (quantitative)

Question 2

What are the 2 types of Nominal/qualitative data? give examples

Answer 2

Unordered (e.g. male/female)

Ordered (e.g. small, medium, large)

Question 3

What are the 2 types of ordinal/quantitative data? give examples

Answer 3

Discrete/whole numbers (e.g. students on the course, children in the family)
Continuous (e.g. weight in kg)

Question 4

When analysing ordinal data, what are the 2 ways in which it can be analysed?

Answer 4

can be analysed by both, parametric or non-parametric tests

Question 5

When would parametric and non-parametric tests be used to analyse data?

Answer 5

If the distribution is normal – use parametric test;

If the distribution is skewed – use a non-parametric test

Question 6

Give Examples of non-parametric tests

Answer 6

Mann-Whitney, Wilcoxon, Kruskal-Wallis

Question 7

Give Examples of Parametric tests

Answer 7

t-tests and Anova

Question 8

What test is used to determine if there is a significant association between the two categorical variables(e.g., male/female voters vs voting preference (Labour, Conservative) ?

Answer 8

Chi2 (squared)

Question 9

Define skewed distribution of data

Answer 9

Skewed distributions are asymmetrical and have data that clusters toward one end

Question 10

How is normal distribution of data displayed ?

Answer 10

represents the distribution of many random variables as a symmetrical bell-shaped graph.

Question 11

Define qualitative data

Answer 11

method of observation to gather non-numerical data.

Question 12

Define quantitative data

Answer 12

measures of values or counts and are expressed as numbers

Question 13

Define mean

Answer 13

the sum of all the samples, divided by the number of samples (n).

Question 14

Define median

Answer 14

the value halfway through the ordered data set, below and above which there lies an equal number of data values.

Question 15

Define quartile

Answer 15

Lower (first) quartile chosen to place 25% of the data below it, 75% above it
Upper (third) quartile chosen to place 75% of the data below it, 25% -above it

Question 16

Define IQR

Answer 16

IQR (Third Quartile minus First Quartile) quantifies the spread or dispersion of the sample
Q3 - Q1

Question 17

Define Confidence Interval

Answer 17

The CI is a range of values, above and below a finding, in which the actual value is likely to fall.

Question 18

Define p-value

Answer 18

p value - indicates how likely it is that a result occurred by chance alone

Question 19

Define effect size

Answer 19

way of quantifying the difference between two data groups

Question 20

What does p = 0.05 mean?

Answer 20

95% sure that difference between data sets is real

Question 21

What’s the difference between statistical and clinical significance?

Answer 21

If a result is statistically significant it means it was unlikely to have occurred by chance.
If it is clinically significant, then it reflects its importance on clinical practice

Question 22

when should t-test be used?

Answer 22

When we want to compare the means of two sets of scores

Question 23

Difference between paired and unpaired t-test data?

Answer 23

Paired: eechnumber in group 1 is linked to a number in group 2 and the difference between each pair is investigated

Question 24

Difference between paired and unpaired t-test data?

Answer 24

Paired: each number in group 1 is linked to a number in group 2 and the difference between each pair is investigated
Unpaired: numbers one each group are unrelated to each other

Question 25

when should anova test be used?

Answer 25

When there are more than 2 sets of data/conditions and more than 1 Independent Variable needs to be compared.