05/21/2024 Readings Flashcards
Number or Category
Value
Condition of characteristic that can have different values (Stress level, age, gender, religion)
Variable
A particular person’s value on a variable
Score
Variable whose values are numbers (as opposed to a nominal variable); also called a quantitative variable
Numeric Variable
variable in which the numbers stand for approximately equal amounts of what is being measured (GPA)
Equal-Interval Variable
An equal interval variable is measured on a ratio scale if it has an absolute zero point, meaning that the value of zero on the variable indicates a complete absence of the variable
Ratio Scale
a variable in which the numbers stand only for relative ranking (students standing in class)
Rank-Order Variable
a variable with values that are categories (that is they are names rather than numbers); categorical variable
Nominal Variable
Types of underlying numerical information provided by a measure such as equal-interval, rank-order- and nominal (categorical)
Levels of Measurement
Variable that has specific values and that cannot have values between these specific values
Discrete Variable
Variable for which in theory there are an infinite number of values between any two values
Continuous Variable
Ordered listing of number of individuals having each of the different values for a particular variable
Frequency Table
Range of values in a grouped frequency table that are grouped together (If the ___ size is 10, one of the ____ might be from 10 to 19)
Interval
Frequency table in which the number of individuals (frequency) is given for each interval of values
Grouped Frequency Table
Bar-like graph of a frequency distribution in which the values are plotted along the horizontal axis and the height of each bar is the frequency of that value;
Histogram
Pattern of frequencies over the various values; what a frequency table, histogram, or frequency polygon describes
Frequency Distribution
Frequency Distribution with one value clearly having a larger frequency than any other
Unimodal Distribution
Frequency distribution with two approximately equal frequencies, each clearly larger than any of the others.
Bimodal Distribution
Frequency distribution with two or more high frequencies separated by a lower frequency; a bimodal distribution is the special case of two high frequencies.
Multimodal Distribution
Frequency distribution in which all values have approximately the same frequency
Rectangular Distribution
Distribution in which the pattern of frequencies on the left and right side are mirror images of each other
Symmetrical Distribution
Distribution in which the scores pile up on one side of the middle and are spread out on the other side; distribution that is not symmetrical
Skewed Distribution
Situation in which many scores pile up at the lowest end of a distribution (creating skewness to the right) because it is not possible to have any lower score
Floor Effect
situation in which many scores pile up at the high end of a distribution (creating skewness to the left) because it is not possible to have a higher score.
Ceiling Effect
specific, mathematically defined, bell-shaped frequency distribution that is symmetrical and unimodal; distributions observed in nature and in research commonly approximate it.
Normal Curve
extent to which a frequency distribution deviates from a normal curve in terms of whether its curve in the middle is more peaked or flat than the normal curve.
Kurtosis
Typical or most representative value of a group of scores
Central Tendency
Arithmetic average of a group of scores
Mean
Value with the greatest frequency in a distribution
Mode
middle score when all the scores in a distribution are arranged from lowest to highest
Median
Score with an extreme value (very high or very low) in relation to the other scores in the distribution
Outlier
Measure of how spread out a set of scores are; average of the squared deviations from the mean
Variance
Score minus the mean
Deviation Score
square of the difference between a score and the mean
Squared Deviation Score
total of each score’s squared difference from the mean
Sum of Squared Deviations
square root of the average of the squared deviations from the mean; the most common descriptive statistic for variation; approximately the average amount that scores in a distribution vary from the mean
Standard Deviation
sum of squared deviations (variance formula)
summation (X-M)^2; SS/N
