Descriptive Statistics Flashcards
Mode
Most frequent score
Strengths of using the mode
- not affected by outliers
- helpful for discrete numbers eg average fam has 2 children not 1.89
- giving the modal group is the only way of giving the average of data in categories eg average pet choice
Weakness of the mode
X There can be no modes if every value is different or multiple modes; this is especially likely in small data sets. This means in some cases, the mode does not give an exact average value.
X The mode does not include all of the values in its calculation, so it is not as
sensitive as the mean measure of central tendency.
Median
Middle value after ordering is ascending order
Strengths of the median
- not affected by outliers
- easy to calc
Weakness of the median
X The median score does not include all of the values in its calculation, so it is not as sensitive as the mean measure of central tendency.
X If there are an even number of data points, unlike the mode, the “typical” value will be a number that is not one of the recorded values.
Mean
Average
Strength of the mean
All raw data points are represented so it’s the most sensitive measure of central tendency
Weaknesses of mean
Due to sensitivity it can be distorted y outliers (extremely low or high values)
Range strengths
Easy to calc esp considering the alt which is standard dev
Weaknesses of the range
Extremely low scores distort the value
The range does not shoe if the scores are clustered around the mean or equally spread out
Standard deviation
Summaries the spread of value so bigger the sd the greater the spread of scores low sd means more consistent
Strengths of sd
Includes all values in its calc making it more sensitive to the range
Provides info regarding spread of scores
Weaknesses of sd
Extreme scores can distort
Sd harder to calc than the range
