vocab 3 Flashcards
A measure of variability derived by calculating the difference between the individual raw scores and the mean (ignoring + or - sign), adding up those difference scores, and then dividing by the number scores. It is the average of all difference scores from the mean. It is the average that all raw scores deviate from the mean.
average deviation
An indication of how much variance is shared by the x- and the y- variables.
Coefficient of Determination:
: A scale used to measure a continuous variable.
Continuous Scale
A number that provides us with an index of the strength of the
relationship between two things.
Correlation Coefficient:
: Expression of the degree and direction of correspondence between two
things.
Correlation
An “eyeball gauge” of how curved a graph is.
Curvilinearity:
Scale used to measure a Discrete Variable
Discrete Scale:
A set of raw scores arrayed for studying or viewing.
Distribution:
A statistic used to express the strength of the relationship or the magnitude of the differences in data; in a meta-analysis, this statistic is typically a correlation
coefficient.
Effect Size:
The collective influence of all the factors on a test score or measurement beyond
those specifically measured by the test or measurement.
Error:
A professional practice that is based on clinical and research
findings.
Evidence Based Practice:
All scores are listed alongside the number of times each score
occurred, may be a table or a graph.
. Frequency Distribution:
Data expressed by a continuous line connecting the points where test
scores or intervals (x) meet frequencies (y).
Frequency Polygon:
Test score intervals replace the actual test scores.
Grouped Frequency Distribution:
Graph
Histogram:
The distance between Q1 and Q3
Interquartile Range:
Have features of both Nominal and Ordinal scales, but also contain equal
intervals between numbers.
Interval Scales:
The steepness of a distribution at its center.
. Kurtosis:
One that retains a direct numerical relationship to the original raw
score.
Linear Transformation:
A statistic that indicates the average or midmost score
between the extreme scores in a distribution.
Measure of Central Tendency:
The act of assigning numbers or symbols to characteristics of things.
Measurement:
These include the range, the interquartile range, the semi-
interquartile range, the average deviation, the standard deviation, and the variance.
Measures of Variability:
A family of techniques used to statistically combine information across
studies to produce single estimates of the data under study
Meta-Analysis:
When relatively few scores fall at the low end of the distribution.
Negative Distribution:
The simplest form of measurement, involves classification or categorization based on one or more distinguishing characteristics.
Nominal Scales
May be required when data under consideration are not normally distributed yet comparisons with normal distributions need to be made.
Nonlinear Transformation:
Stretching the skewed curve into the shape of a normal curve and creating a corresponding scale of standard scores (Normalized Standard Score Scale).
Normalizing a Distribution:
Have the same features as Nominal scales, but also permits rank ordering on some characteristics.
Ordinal Scales:
Relatively flat
Platykurtic
Somewhere in the middle
Mesokurtic
Relatively peaked
Leptokurtic
When relatively few scores fall at the high end of the distribution.
Positive Skew:
In addition to the features in the three pervious scales, _______ also
have a true point zero.
Ratio Scales:
An unmodified accounting of performance, usually a number.
Raw Score:
The set of numbers or symbols whose properties model empirical properties of the
objects to which the numbers are assigned.
Scale:
The interquartile range divided by 2
Semi-Interquartile Range:
The nature and extent to which symmetry is absent.
Skewness:
An index of correlation that may be the statistic of choice when the
sample size is small and both sets of measurements are ordinal.
Spearman’s Rho:
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.
Standard Deviation:
: Raw score that has been converted from one scale to another.
Standard Score
Named for Thorndike, a standard score calculated using a scale with a mean set
at 50 and a standard deviation set at 10, used by the developers of the MMPI.
T-Score:
An indication of how scores in a distribution are scattered or dispersed.
Variability:
The arithmetic mean of the squares of the difference between the scores in a
distribution and their mean.
Variance:
A standard score derived by calculating the difference between a particular raw
score and the mean and then dividing by the standard deviation; a ______ expresses a score in terms of standard deviation units that the raw score is below or above the mean of the distribution. A ______ is a standard deviation scale with a mean of zero and a standard deviation of 1.
Z-Score:
