descriptive statistics: measures of dispersion Flashcards
research methods
1
Q
What are the measures of dispersion?
A
Range
Standard deviation
Percentages
2
Q
What is the range?
A
The difference between the highest and lowest score
3
Q
What are the advantages of the range?
A
- quick and easy to work out
- takes into account the full spread of data
4
Q
What are the disadvantage of the range?
A
- can be affected by extreme sores
- only look at highest and worst number, not all data
5
Q
What is standard deviation?
A
Th measure of spread of scores from the mean. It is calculated by considering the distance of each score from the mean. The larger the standard deviation, the larger the spread of scores from the mean.
6
Q
What are the advantages of standard deviation?
A
- more sensitive than the range as all scores are used to calculate it
- describes spread of scores with precision
7
Q
What are the disadvantages of standard deviation?
A
- complicated to calculate
- less meaningful if the data aren’t normally distributed
8
Q
How do you work out percentages for increases and decreases?
A
Increase- (new number-original number) ÷ original number x100
Decrease- (original number-new number) ÷ original number 100
