Measure of central tendency when distribution is normal and data is at least at an interval level of measurement.
Measure of variability when distribution is normal and data is at least at an interval level of measurement.
Measure of central tendency when distribution is skewed and unimodal and/or data is at an ordinal level of measurement.
Measure of variability when distribution is skewed and unimodal.
Measure of variability to report when one calculates a mean.
Measure of variability found by squaring a standard deviation.
Approximate percentage of scores found within the range of one standard deviation of a mean
34% + 34% = 68%
Approximate percentage of scores found within the range of two standard deviations from the mean
Examples of measures of central tendency
Mean, median mode
Examples of measures of variability
Range, interquartile range, standard deviation, variance
Middle-most score in an ordered distribution of scores
P.25 to P.75
Lowest to highest score
Mean of a population
Examples of descriptive statistics
measures of central tendency and measures of variability; graphs; tables
Examples of inferential statistics
t; F, Chi-Square
Statistically significant results
Unlikely NOT to be replicated; probability of failing to replicate being less than 5 in 100.
Percentage of scores falling below a given score.
Most frequently occurring score or category. Stem
Stem and leaf display
Exploratory descriptive data analysis procedure developed by John Tukey to impose order on a set of scores without 9as is the case with a grouped frequency distribution) losing the identity of the individual scores).