Statistics
Collection of methods for planning experiments, obtaining data, organizing, summarizing, presenting, analyzing, interpreting, and drawing conclusions based on data.
Population
the set of all individuals of interest in a particular study
Sample
a set of individuals selected from a population, usually intended to represent the population in a research study
Variable
a characteristic or condition that changes or has different values for different individuals
Data
(plural) measurements or observations
Data Set
a collection of measurements or obsevations
Datum
a single measurement or observation (commonly called a score or raw score)
Parameter
a value, usually a numerical value that describes a population
Statistic
A numerical measurement describing some characteristic of a sample
Sampling Error
the discrepancy or amount of error that exists between a sample statistics and the corresponding population parameter
Correlational Method
two variables are observed to determine whether there is a relationship between them
Experimental Method
a research technique in which an investigator deliberately manipulates selected events or circumstances and then measures the effects of those manipulations on subsequent behavior
Independent Variable
the experimental factor that is manipulated; the variable whose effect is being studied
Dependent Variable
(statistics) a variable in a logical or mathematical expression whose value depends in the independent variable
Variable
a symbol (like x or y) that is used in mathematical or logical expressions to represent a variable quantity
Constant
continually recurring or continuing without interruption
Placebo
an inert (neutral) substance given to the control group in an experiment
Confounding Variable
Type of extraneous variable that is not controlled for; a confounding variable regularly fluctuates with the independent variable and affects the dependent variable