Numbers in a data set that are collected to represent research variables.
Descriptive data
A count of the instances that an event ocurs in a data set
Frequency
A calculated count dereived from dividing the frequency of an event in a given time period by all possible occurrences of the event during the same time period.
Rate
A new variable produced when data from other variables are combined using a simple formula.
Derived variable
A type of frequency distribution in which variables with different values are plotted as a graph on x-axes and y-axes, and the shape can be visualized.
Histogram
The avereage; a measure of central tendency.
Mean
A measure of central tendency that is the exact midpoint of the numbers of the data set
Median
A measure of central tendency that is the most frequently occurring value in the data set.
Mode
A measure of variability that is the distance between the two most extreme values in the data set.
Range
A emasure of variability that gives information about the spread of scores around the mean.
Variance
The most easily interpreted measure of variability of scores around the mean; represents the average amount of variation of data points about the mean.
Standard deviation
A calculation that produces a number that depicts the standard deviation relative to the mean. [CV=100(SD/X)]
Coefficient of variation (CV)
A measure of position that expresses the distance from the mean of a single score in standard terms.
Standardized scores
A bell shaped distribution in which the mean is set at zero and a standard deviation at one.
Standard normal distribution
A measure that depicts the strength and nature of the relationship between two variables.
Correlation analysis
A graphic presentation for nominal or ordinal data that represents the categories on the horizontal axis and frequency on the vertical axis.
Bar chart
A graphic presentation that plots means for a variable over a period of time.
Line graphs
A graphic presentation that marks the median of the values in the middle of the box and the 25th and 75th percentiles as the lower and upper edges of the box. It indicates the relative position of the data for each group and the spread of the data for comparison.
Box plot
A graphic presentation that indicates the nature of the relationship between two variables.