Descriptive statistics -Measures of central tendency and measures of dispersion Flashcards Preview

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Flashcards in Descriptive statistics -Measures of central tendency and measures of dispersion Deck (25):
1

What are descriptive statistics

A describe the data and show as general patterns and trends

2

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

Measures of central tendency and measures of dispersion

3

What is a conclusion?

A conclusion succinctly describes the findings of a study

4

What are inferential statistics?

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

5

What are measures of central tendency?

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

6

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

The mean, median mode

7

How is the mean calculated?

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

8

How is the median calculated?

The median is the middle of value in an ordered list

9

How is the mode calculated?

Mode is a value that is most common

10

What are the strengths of the mean?

It makes use of the values of all the data

11

What are the strengths of the median

It is not affected by extreme scores

12

What are the strengths of the mode?

It is useful when the data are in categories

13

What are the weaknesses of the mean

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

14

What are the weaknesses of the median?

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

15

What other weaknesses of the mode?

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

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

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

17

What are measures of dispersion?

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

18

What is a range?

The range is difference between the highest and lowest number

19

What is standard deviation?

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

20

What are the two main ways of measuring dispersion?

The range and standard deviation

21

Why would we use standard deviation rather than the range

Standard deviation is a more precise method of expressing dispersion

22

What are the strengths of the range?

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

23

What are the weaknesses of the range?

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

24

What are the strengths of standard deviation?

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

25

What other weaknesses of standard deviation?

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