central tendency deviation score interquartile range mean median mode outlier range standard deviation sum of squares variability variance | an average calculated for interval- or ratio-level data by summing all the values in a data set and dividing by the number of cases; abbreviated M. a measure of variability for interval- or ratio-level data; the mean of the squared deviation scores. the score that occurs with the greatest frequency. a measure of variability for interval- or ratio-level data; the distance from the lowest score to the highest score. an extreme (unusual) score that falls far away from the rest of the scores in a set of data. a measure of how far a score falls from the mean, calculated by subtracting the mean from the score. a measure of variability for interval- or ratio-level data; the square root of the variance; a measure of the average distance that scores fall from the mean. squaring a set of scores and then adding together the squared scores; abbreviated SS. how much variety (spread or dispersion) there is in a set of scores. a value used to summarize a set of scores; also known as the average. a measure of variability for interval- or ratio-level data; the distance covered by the middle 50% of scores; abbreviated IQR. an average calculated by finding the score associated with the middle case, the case that separates the top half of scores from the bottom half; abbreviated Mdn; can be calculated for ordinal-, interval-, or ratio-level data. |