A Statistics Refresher Flashcards
(19 cards)
Correlation
an expression of the degree and direction of correspondence between two things
Evidence-based practice
Methods, protocols, techniques, and procedures, used by professionals, that have a basis in clinical and research findings
Histogram
A graph with vertical lines drawn at the true limits of each test score (or class interval), forming a series of contiguous rectangles
Mean
a measure of central tendency and a statistic at the ratio level of measurement
mode
a measure of central tendency that is nominal in nature
median
a measure of central tendency that takes into account the order of scores and is ordinal in nature
Nominal
classification or categorization based on one or more distinguishing characteristics, where all things measured must be placed into mutually exclusive and exhaustive categories
ordinal
categories with a clear and uncontroversial order
Measurements in which people are ranked
interval
meaningful distances between numbers
ratio scales
true zero point, which indicates the absence of the thing being measured
Pearson r
a widely used statistic for obtaining an index of the relationship between two variables when that relationship is linear and when the two correlated variables are continuous
Normal distribution
a distribution with the greatest frequency of scores occurring near the arithmetic mean
Positive Skew
When relatively few of the scores fall at the high end of the distribution
Negative Skew
Relatively few scores in a distribution fall at the low end
Scatterplot
bivariate distribution
a graphic representation of correlation accomplished by the simple graphing of the coordinate points for values of the X-variable and the Y-variable
Standard deviation
A measure of variability equal to the square root of the averaged squared deviations about the mean; a measure of variability equal to the square root of the variance
Variance
A measure of variability equal to the arithmetic mean of the squares of the differences between the scores in a distribution and their mean
T scores
standard score calculated using a scale with a mean set at 50 and a standard deviation set at 10
Z scores
A standard score derived by calculating the difference between a particular raw score and the mean and then dividing by the standard deviation; a z score expresses a score in terms of the number of standard deviation units that the raw score is below or above the mean of the distribution
