Descriptive statistics -Measures of central tendency and measures of dispersion

Question 1

What are descriptive statistics

Answer 1

A describe the data and show as general patterns and trends

Question 2

There are two main ways to summarise data what are they?

Answer 2

Measures of central tendency and measures of dispersion

Question 3

What is a conclusion?

Answer 3

A conclusion succinctly describes the findings of a study

Question 4

What are inferential statistics?

Answer 4

Where you make an inference from the conclusions based on the participants in your study and extend it to all people

Question 5

What are measures of central tendency?

Answer 5

they inform us about central or middle values for a set of data – they are averages

Question 6

An average can be calculated in three different ways - what are they?

Answer 6

The mean, median mode

Question 7

How is the mean calculated?

Answer 7

By adding up all the numbers and dividing by the number of numbers

Question 8

How is the median calculated?

Answer 8

The median is the middle of value in an ordered list

Question 9

How is the mode calculated?

Answer 9

Mode is a value that is most common

Question 10

What are the strengths of the mean?

Answer 10

It makes use of the values of all the data

Question 11

What are the strengths of the median

Answer 11

It is not affected by extreme scores

Question 12

What are the strengths of the mode?

Answer 12

It is useful when the data are in categories

Question 13

What are the weaknesses of the mean

Answer 13

It can be unrepresentative of the numbers if there are extreme values

Question 14

What are the weaknesses of the median?

Answer 14

Not as sensitive as the mean because not all values are reflected in the median

Question 15

What other weaknesses of the mode?

Answer 15

Not a useful way of describing data when there are several nodes

Question 16

What is the top tip when dealing with this typical exam question: identify a suitable method of central tendency to use with the results from this study and explain why you would choose the method

Answer 16

Look to see if there are any extreme values in the dataset given and if there are then the median is best

Question 17

What are measures of dispersion?

Answer 17

A set of data can be described in terms of how dispersed or spread out the numbers

Question 18

What is a range?

Answer 18

The range is difference between the highest and lowest number

Question 19

What is standard deviation?

Answer 19

This is a measure of the spread of the data around the mean

Question 20

What are the two main ways of measuring dispersion?

Answer 20

The range and standard deviation

Question 21

Why would we use standard deviation rather than the range

Answer 21

Standard deviation is a more precise method of expressing dispersion

Question 22

What are the strengths of the range?

Answer 22

It is easy to calculate and it provides you with direct information without having to do many calculations

Question 23

What are the weaknesses of the range?

Answer 23

It can be affected by extreme values and it doesn’t take into account the number of observations in the data set

Question 24

What are the strengths of standard deviation?

Answer 24

It is a more precise measure of dispersion because all values are taken into account

Question 25

What other weaknesses of standard deviation?

Answer 25

It is unduly affected by extreme values which increase the standard deviation and make it less representative of the dataset