Descriptive statistics Flashcards
Name 3 measures of central tendency
Mean
Median
Mode
What is a strength and limitation of using the mean?
Strength:all scores are taken into account so therefore more representative of the data
Limitation: it can be skewed by extreme scores
What is a strength and limitation of using the median?
Strength: not skewed by extreme scores
Limitation: doesn’t take into account all scores
What is a strength and limitation of using the mode?
Strength: only measure that can be used on all types of data
Limitation: may be several modes
When do you use the mode, mean and median?
Mode: when data is categorical (people in a group rather than individual scores
Mean: no extreme scores
Median: 1 or more extreme scores
What is meant by a normal distribution?
Mean, mode and median are roughly the same
What is meant by a positive skew?
The mean is higher than the mode
What is meant by a negative skew?
The mean is lower than the mode
What are the 2 measures of dispertion?
Range
Standard deviation
Why is it better to use standard deviation rather than the range?
It takes into account all of the scores, not just the highest and lowest
What does high standard deviation say about the scores?
The greater the variation or spread of scores from the mean
What does low standard deviation tell us about the scores?
There is little variation in the scores- they all cluster around the mean
