
Table
a display of data in a matrix format

graph
a representation of data by spatial relationships in a diagram

frequency distribution
a graph that shows the number of scores that fall into specific bins,or divisions of the variable

histogram
a frequency distribution in which the frequencies are represented by contiguous bars

frequency polygon
a frequency distribution in which the frequencies are connected by straight lines

normal curve
a bell shaped cure described by a certain mathemeatical function

skewed
a distribution that is not symmetrical

cumulative frequency distribution
a frequency distribution that shows the number of scores that fall at or below a certain score

scattergram
a graph showing the responses of a number of individuals on two variables; visual display of correlational data

median split
a division of the subjects in a study into two groups of equal size on the basis of one of the variables

line graph
a graphical representation using lines to show relationships between quantitative variables

bar graph
graphical representation of categorical data in which the heights of separated bars, or columns, show the relationships between variables

timeseries graph
a graph in which the abscissa (xaxis) represents time

error bars
in a graph, vertical lines that indicate plus or minus one standard deviation of the data or, less frequently, the standard error of the mean

boxandwhisker plot
a typeof graph based on median and percentiles rather than mean and standard deviation

data reduction
the process of transcribing data from individual data sheets to a summary form

coding guide
a record that specifies the variables of a study, the columns they occupy in the data file, and their possible values

invalid data
data points that fall outside the defined range for that variable of data

missing data
empty cells in a data matrix

outliers
dat points that are highly improbable, although not impossible

missing data code
a symbol, such as an asterisk, that is entered ina cell that has no data

validity
an indication of accuracy in terms of the extent to which a research conclusion corresponds with reality

internal validity
extent to which a study probides evidence of a causeeffect relationship between the independent and dependent variables

