Research Methods: measures of central tendency and dispersion

Question 1

Definition of descriptive statistics ?

Answer 1

The use of graphs tables and summary statistics to identify trends and analyse data

Question 2

Describe measures of statistics ?

Answer 2

The general term for any measures of the average value in a set of data

Question 3

Describe what it means by the mean ?

Answer 3

The arithmetic average calculated by adding up all the values in a set of data and dividing them by the number of values there are

Question 4

Describe the median ?

Answer 4

The central value in a set of data when values are arranged from lowest to highest

Question 5

Describe the mode

Answer 5

The most frequently occurring value in a set of data

Question 6

What does it mean by bimodal

Answer 6

When there are two modes

Question 7

Definition of measures of dispersion

Answer 7

General term for any measure of the spread or variation in a set of scores

Question 8

What does it mean by the range ?

Answer 8

A simple calculation of dispersion in a set of scores which is worked out by subtracting the lowest score from the highest score

Question 9

Definition of standard deviation ?

Answer 9

A calculation which tells us how much scores deviate from the mean by calculating the difference between the mean and each score

Question 10

Strength of calculating a mean (central tendency)

Answer 10

Most sensitive measure of central tendency
Includes all the values within calculation
Most representative

Question 11

Limitation of calculating the mean (extreme values)

Answer 11

Easily distorted by extreme values
Score that is very different from other scores moves mean closer to outlier
Susceptible to skewing

Question 12

Limitation of calculating a mean (universal measure)

Answer 12

Mean only used with values that represent universal safe measures
Only values that are in seconds , centimetres
Limits which types of data the mean can be used for

Question 13

Strength of using the median ( extreme values)

Answer 13

Not easily distorted by extreme values
Middle number is not impacted by outlier
Not susceptible to skewing of final calc

Question 14

Strength of the median (ease)

Answer 14

Easy to calculate
Numbers in order then central value identified
No issues with data analysis

Question 15

Limitation of median ( sensitivity)

Answer 15

Not as sensitive as mean
Doesn’t include all the values
Not representative of data as whole

Question 16

Strength of median (universal measures )

Answer 16

Used with values that do not represent a universal measure
Scores from a rating scale
Not limited to which types of data used

Question 17

Strength of the mode (ease)

Answer 17

Very easy to calculate
Only identify number which occurs the most
No issues with data analysis

Question 18

Strength of using the mode (nominal data)

Answer 18

Only method that can be used with nominal data
Only way to identify most typical / average value is select models groups
Value of mode is demonstrated

Question 19

Limitation of mode (crude )

Answer 19

Crude measure
Mode normally very different from mean and mode
Not representative of data as a whole

Question 20

3 Measures of central tendency

Answer 20

Mean
Median
Mode

Question 21

2 Measures of dispersion

Answer 21

Range

Standard deviation

Question 22

What is a strength of the range (ease)

Answer 22

Easy to calculate
Take lowest from highest
No issues with data analysis

Question 23

Limitation of range (extreme values )

Answer 23

Only takes in account two most extreme values
Unrepresentative of data as a whole
Eg lowest score 0 highest score 100
Range = 100

Question 24

The smaller the standard deviation the ….

Answer 24

Tighter the dispersion within data spread

Question 25

What does it mean by tighter dispersion

Answer 25

People are similarly impacted by the IV in an experiment

not a lot of variation between data scores and mean

Question 26

The larger the standard deviation the ….

Answer 26

Greater the dispersion within data set

Question 27

What does it mean If dispersion is greater within data

Answer 27

People are impacted differently by an IV in an experiment
Large variation between data scores and the mean
More individual differences

Question 28

Strength of standard deviation (preciseness )

Answer 28

More precise measurement of dispersion than range
Includes all values within final calc
More representative

Question 29

Limitations of standard deviation (extreme values)

Answer 29

Easily distorted by extreme values
Score that is very different moves mean closer to outlier
Affects standard deviation
Susceptible to skewing of final calc