the extent to which a test measures or predicts what it is supposed to
Numerical data based on measurements of a participant's response that can be directly observed and verified by the researcher.
the small group of participants, out of the total number available, that a researcher studies
An association between two or more variables.
A research design in which the researcher collects quantitative data based on pre-existing criteria or variables.
The system of moral principles and rules that becomes standards for professional conduct
the method used to explore cause and effect with manipulation or one or more factors (independent variables) and using random assignment
-- A variable that confuses the association between the independent and dependent variables and thus needs to be restricted either within the research design or through statistic procedures
the experimental factor that is manipulated; the variable whose effect is being studied
all the cases in a group, from which samples may be drawn for a study
the group that does not receive the experimental treatment.
approximate distribution of scores expected when a sample is taken from a large population, drawn as a frequency polygon that often takes the form of a bell-shaped curve, called the normal curve
The middle number in a set of numbers that are listed in order
the outcome factor; the variable that may change in response to manipulations of the independent variable
the ability of a test to give the same results under similar conditions
a procedure to inform participants about the true nature of an experiment after its completion
not having to do with numbers
a computed measure of how much scores vary around the mean score
an average of n numbers computed by adding some function of the numbers and dividing by some function of n
the difference between the highest and lowest scores in a distribution
an assumption about behavior that is tested through scientific research
Numerical data determined by the research participants that the researcher cannot directly verify and therefore cannot be certain of its accuracy.