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

Psychology A2 Research Methods > Descriptive statistics -Measures of central tendency and measures of dispersion > Flashcards

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

What are descriptive statistics

A

A describe the data and show as general patterns and trends

2
Q

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

A

Measures of central tendency and measures of dispersion

3
Q

What is a conclusion?

A

A conclusion succinctly describes the findings of a study

4
Q

What are inferential statistics?

A

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

5
Q

What are measures of central tendency?

A

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

6
Q

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

A

The mean, median mode

7
Q

How is the mean calculated?

A

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

8
Q

How is the median calculated?

A

The median is the middle of value in an ordered list

9
Q

How is the mode calculated?

A

Mode is a value that is most common

10
Q

What are the strengths of the mean?

A

It makes use of the values of all the data

11
Q

What are the strengths of the median

A

It is not affected by extreme scores

12
Q

What are the strengths of the mode?

A

It is useful when the data are in categories

13
Q

What are the weaknesses of the mean

A

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

14
Q

What are the weaknesses of the median?

A

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

15
Q

What other weaknesses of the mode?

A

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

16
Q

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

A

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

17
Q

What are measures of dispersion?

A

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

18
Q

What is a range?

A

The range is difference between the highest and lowest number

19
Q

What is standard deviation?

A

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

20
Q

What are the two main ways of measuring dispersion?

A

The range and standard deviation

21
Q

Why would we use standard deviation rather than the range

A

Standard deviation is a more precise method of expressing dispersion

22
Q

What are the strengths of the range?

A

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

23
Q

What are the weaknesses of the range?

A

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

24
Q

What are the strengths of standard deviation?

A

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

25
Q

What other weaknesses of standard deviation?

A

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