Descriptive statistics Flashcards
What are measures of central tendency?
Any measure which calculates an average value within a data set
What is a strength of Mean?
uses all values
good for interval data
What is a limitation of mean?
Influenced by outliers so can be unrepresentative
What is a strength of Median?
Not affected by outliers
Good for ordinal data
What is a limitation of Median?
Does not use all data so not as sensitive as mean
What is a strength of Mode?
useful for nominal data
What is a limitation of Mode?
not useful when there are several modes
What are measures of dispersion?
Any measure that calculates the variation in a data set
What is a strength of Range?
Easy to calculate
What is a limitation of Range?
Affected by outliers
Does not use all data
How is Standard Deviation calculated?
1) Mean of all values
2) Subtract mean from each score
3) Square this number
4) Add these together
5) Divide this sum by the number of scores
6) Square root this number
What does a low SD mean?
Data more clustered close to the mean and so not very spread out
What does a high SD mean?
Data not close to mean and so is spread out
What is a strength of SD?
Precise measure with all values
What is a limitation of SD?
Difficult to calculate
Affected by outliers`
