Descriptive Statistics

Question 1

● What is the mode?

Answer 1

Most common or popular number in set of scores

Question 2

● Can there be more than one mode in a data set? What is this called?

Answer 2

Yes / Bimodal

Question 3

● With which data is mode used?

Answer 3

Nominal data

Question 4

● What is the median?

Answer 4

Central/middle score in a list of ranked-ordered scores

Question 5

● What is done if there are two central scores for the median?

Answer 5

Add together and divide by 2

Question 6

● With which data is median used?

Answer 6

Ordinal data

Question 7

● What is the mean?

Answer 7

All scores added up and divided by total number of scores

Question 8

● With which data is mean used?

Answer 8

Interval data

Question 9

● What is meant by measures of central tendency?

Answer 9

The average value in a set of data

Question 10

● What is the range?

Answer 10

Spread of data from smallest to largest value plus 1

Question 11

● With which data is range used?

Answer 11

Ordinal data

Question 12

● What is standard deviation?

Answer 12

Measure of spread around the mean

Question 13

● With which data is standard deviation used?

Answer 13

Interval data

Question 14

● What does a high SD mean?

Answer 14

Scores are more spread around the mean

Question 15

● What does a low SD mean?

Answer 15

Scores are less spread around the mean

Question 16

● What is meant by measures of dispersion?

Answer 16

Based on the spread of scores

Question 17

● Give one way to display measures of central tendency.

Answer 17

Tables

Question 18

● Give one way to display measures of dispersion.

Answer 18

Graphs

Question 19

● What is a worked example for the mean calculation?

Answer 19

Add all values and divide by the number of values

Question 20

▲ Why is the mode easy to calculate?

Answer 20

Because it is just the most frequent value

Question 21

▲ Why is the mode less prone to distortion by extreme values?

Answer 21

It does not take all data into account

Question 22

▲ Why is the mean the most sensitive measure of central tendency?

Answer 22

Because it uses all data sets

Question 23

▲ Why can the mean be misleading?

Answer 23

Affected by extreme (freak) scores

Question 24

▲ Why might the mode be less useful in some data sets?

Answer 24

There may be more than one mode

Question 25

▲ Why is the median not as sensitive as the mean?

Answer 25

It does not use all scores

Question 26

▲ Why is the range quick and easy to calculate?

Answer 26

Only uses 2 pieces of data

Question 27

▲ How can the range be distorted?

Answer 27

By extreme (freak) scores

Question 28

▲ Why is the standard deviation more precise than the range?

Answer 28

Uses all scores in calculation

Question 29

▲ Why is standard deviation less easily distorted by extreme values?

Answer 29

Takes into account distance from mean

Question 30

▲ What does a high mean score generally indicate?

Answer 30

Greater score/effect

Question 31

▲ What does a high SD indicate about individual differences?

Answer 31

More individual differences

Question 32

▲ What does a low SD indicate about consistency?

Answer 32

More consistency in results

Question 33

▲ Why do psychologists display descriptive statistics in tables?

Answer 33

To summarise central tendency and dispersion

Question 34

▲ When interpreting means and SDs, what must you always do?

Answer 34

Explain what the values suggest about the DV

Question 35

✪ Evaluate why the mode may not be useful if there is more than one mode in a data set.

Answer 35

Moreover, the mode may not be useful if there is more than one mode in a data set.

Question 36

✪ Explain the main advantage of the mean over the median.

Answer 36

Mean is most accurate and sensitive measure of central tendency as uses all data sets UNLIKE the median which does not take account of all data.

Question 37

✪ Evaluate why the mean can result in misleading interpretations.

Answer 37

Affected by extreme (freak) scores as takes all scores into account which can result in misleading interpretation of results.

Question 38

✪ Critically discuss why the median may be less useful than the mean

Answer 38

Not as sensitive as mean as does not use all scores meaning less useful results.

Question 39

✪ Discuss the precision of standard deviation versus range.

Answer 39

Most precise/sensitive measure of dispersion as uses all scores in calculation making it a more accurate measure of dispersion than the range, which only looks at the smallest and largest data.

Question 40

✪ Critically evaluate how extreme values affect the mean

Answer 40

Mean is highly influenced by extreme scores as it takes all data in to account.

Question 41

✪ Evaluate how the use of all scores in standard deviation calculation increases its accuracy

Answer 41

Standard deviation uses all scores in calculation making it a more accurate measure of dispersion than the range.

Question 42

✪ Explain what a high SD tells us about individual differences

Answer 42

The higher the SD the more the data is spread around the mean, less consistency and more individual differences.

Question 43

✪ Explain what a low SD tells us about consistency

Answer 43

The smaller the calculated number, the data is clustered around the mean so more consistency and less individual differences.

Question 44

✪ Critically evaluate the usefulness of range versus standard deviation

Answer 44

Range can be distorted by extreme (freak) scores, as it only takes in to account the highest and lowest scores, so an inaccurate range could be achieved. Standard deviation is less easily distorted by extreme values.

Question 45

✪ Discuss why SD is preferred for interval data.

Answer 45

Standard deviation is used for interval data as it uses all scores and is more precise than the range.

Question 46

✪ Discuss what the mean provides in relation to the DV

Answer 46

Provides a good indication of the average/typical score participants gain on the DV.

Question 47

✪ Explain why the context is important when interpreting mean scores.

Answer 47

Although generally the higher the mean that is gained then the greater the score/effect (although this is not always the case! Do double check in the scenario what a high score will mean).