Unit 1 - Descriptive Statistics Flashcards
What are the measures of central tendency?
Mean, Median, Mode.
How is the mean calculated?
Add all numbers together, divide by number of participants.
How is the median calculated?
Middle number, put numbers into order ranging from lowest to highest, choose middle.
How is the mode calculated?
Most occurring.
What is a strength of the mean?
Accurate average, and takes into account all the scores.
What is a weakness of the mean?
Outlier scores can skew the mean to not reflect most participants.
What is a strength of the median?
Not affected by outlier scores, so results will not be skewed.
What is a weakness of the median?
Does not take into account all scores.
What is a strength of the mode?
Can be used for non-numerical data.
What is a weakness of the mode?
Impossible to calculate if all data is different, or the may be more than one mode.
What are the measures of dispersion?
Range, Variance, Standard Deviation.
How is the range calculated?
Largest score minus smallest score.
How is the variance calculated?
For each condition, calculate the mean. Within each, subtract each participant’s score from the mean for that condition (‘d’ difference). Then square each ‘d’ score (d^2). Then add all d2 scores together to get Ed2, then subtract by n-1.
How is standard deviation calculated?
Square root of variance.
What is a strength of range?
Quick and easy to calculate.