16. Descriptive statistics

Cards (19)

What is mean
Adding up all scores and dividing by the total number
Mean- strengths
Includes all scores
More representative
Mean - limitations
Easily distorted
What is median
Middle value when scores are arranged lowest to highest - if there are 2 Middle numbers, add both and divide by 2
Median- strengths
Not affected by extreme scores
Easy to calculate
Median- limitations
Not as sensitive, not all scores are included
What is mode
Most frequently occurring score
Mode- strengths
Easy to calculate
Unaffected by extreme values
Mode- limitations
Not very useful if there are several modes
What is central tendency
Mean
Median
Mode
What are the measures of dispersion
Range
Standard deviation
What is the range
Subtracting large number from small and adding 1
Range- strength
Easy measure of dispersion
Shows how representative median is
Range - limitations
Only takes into account the 2 extreme values
Unrepresentative
What is standard deviation
Single value
Tells us how far scores deviate ( move away) from the mean
What does it mean if the standard deviation is high
The result are inconsistent
What does it mean if the deviation is low
The results are tightly clustered around
All participants anwsered fairly similar
Standard deviation- strength
More precise measure of dispersion as it includes all values
Standard deviation - limitaions
Affected by a single extreme value
Complicated to carry out

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