Descriptive statistics

Question 1

Define Categorical data

Answer 1

Has 2 or more categories with no ordering to them (usually binary or nominal)

Question 2

Define discrete data

Answer 2

Has a fixed value with a logical order (usually ordinal, ratio, or interval variables)

Question 3

Define continuous data

Answer 3

Can take any fractional value (usually ratio or interval variables)

Question 4

How can frequencies be presented?

Answer 4

As its raw frequency or as a percentage frequency

Question 5

Define Mode

Answer 5

The score occurring most often in a dataset

Question 6

Define Median

Answer 6

The middle score in a dataset

Question 7

Define Mean

Answer 7

Sum of data point divided by number of data points

Question 8

Define Central tendency

Answer 8

Where the centre of our frequency distribution lies

Question 9

Which bar on a bar chart would be the mode?

Answer 9

The highest bar

Question 10

How would you work out the median in an odd value dataset?

Answer 10

(n+1)/ 2

Question 11

How would you work out the median in an even value dataset?

Answer 11

Middle two values/ 2

Question 12

What are some pros of the median?

Answer 12

Insensitive to outliers, often gives a real data value and is useful for ordinal data

Question 13

What are some cons of the median?

Answer 13

Ignores a lot of the data, difficult to calculate without a computer and can’t be used with nominal data

Question 14

What are some pros of the mean?

Answer 14

Uses all of the data, is most effective for normally distributed datasets

Question 15

What are some cons of the mean?

Answer 15

Sensitive to outliers, values are not always meaningful and is only useful for ratio and interval data

Question 16

What are the measures of spread for the mode?

Answer 16

There are no measures of spread

Question 17

What are the measures of spread for the median?

Answer 17

‘distance-based’ measures e.g. range and interquartile range

Question 18

What are the measures of spread for the mean?

Answer 18

‘centre-based’ measures of spread e.g. variance and standard deviation

Question 19

Define the interquartile range

Answer 19

Ignores most extreme values and is the range of scores within the middle 50% of scores

Question 20

Define the Lower quartile range

Answer 20

Median of lower half of data

Question 21

Define the Upper quartile range

Answer 21

Median of upper half of the data

Question 22

What are the pros and cons identical to?

Answer 22

The median pros and cons

Question 23

Define Deviance

Answer 23

Take each score and subtract it from the mean

Question 24

Define squared errors

Answer 24

Take each deviance score and square it

Question 25

Define the variance

Answer 25

Average squared errors

Question 26

What are the pros of variance?

Answer 26

Uses all of the data and forms the basis of several other tests

Question 27

What are the cons of variance?

Answer 27

Requires a normal distribution and is sensitive to outliers

Question 28

Define Standard deviation

Answer 28

A measure of spread that's equal to the unit of measurement of the dependent variable

Question 29

How would you calculate the Standard deviation?

Answer 29

Using the square root of variance

Question 30

What does the Standard deviation allow us to do?

Answer 30

Get an unbiased estimate of the population's standard deviation if we only have access to a sample of data

Question 31

What can Standard deviance estimate?

Answer 31

Population based on a sample