Glossary Items Starting with "E"
- ecological validity
- Experiments achieve ecological validity when they reproduce accurately real-life situations, thus allowing easy generalization of their findings. See external validity.
- effect size
- An index of the size of the statistical difference between
groups that is expressed in standard deviation units.
- effective range
- Characteristic of any dependent measure; the range
over which the dependent measure accurately reflects the level of the dependent variable.
- electronic mail
- A mechanism for sending messages via
the Internet to anyone that has an electronic mail address.
- See electronic mail.
- Based on observed data.
For example, a relationship between variables is empirically established if it has been observed to occur.
- System of knowing that is based solely on observation of the events.
- enumerative data
- Synonymous with
- equal intervals
- A characteristic of the abstract number system
in which the differences between units are the same anywhere on the scale.
- equipment subsection
- See apparatus subsection.
- error bar
- An addition made to
either histograms or frequency polygons that indicates the size of the
standard error of the mean.
- error term
- Generic term used in many different
statistics; it provides a basis for comparing observed differences between groups. The error term is usually based on a measure of the variability of scores within each group.
- error variance
- A function of the variability of scores within groups.
- ethical checks
- A series of questions that a researcher must ask about the research and the specific procedures included to safeguard participants.
- evaluative biases of language
has a tendency to blend description and evaluation, which can distort the
perceptions of objective behavior.
- ex-post-facto design
- Nonexperimental research design in which the current situation of the participant is observed and related to previous events. Because there are no manipulations of variables,
confounding variables cannot be controlled and alternative hypotheses cannot be ruled out. Therefore, it is a weak design and causal inferences cannot be drawn from it.
- ex-post-facto fallacy
- Error in reasoning
in which one assumes that the observed relationship between current events and some historical events represents a causal relationship.
- ex-post-facto reasoning
- ex-post-facto study
- See ex-post-facto
- exact replication
- Repeating a study by using exactly the same procedure used in the original study. See also
- High-constraint research procedure in which participants
are randomly assigned to two or more conditions and compared on a dependent
measure. Experimental designs provide adequate control over virtually all possible confounding variables.
- experimental analysis of behavior
- Procedures for the controlled study of single individuals or small groups, which are based on B. F. Skinner's operant conditioning concepts.
- experimental design
- In experimental design, participants are assigned to groups or conditions without bias,
such as with random assignment, and all appropriate control procedures are used.
- experimental group
- Group of participants assigned to one or more conditions
defined by a specified level of the independent variable. Contrasted with a control
- experimental level of constraint
- Research in which two or more groups or conditions
are compared on at least one dependent measure. Experimental research provides adequate controls for most confounding variables and, therefore, allows the researcher to draw causal inferences.
- experimental research
experimental level of constraint.
- experimental variance
- Variability among the group means in a research study.
- Process by which a researcher studies the relationship between independent and dependent variables by systematically manipulating the independent
variable and observing the effects of the independent variable on the dependent variable.
- experimenter bias
- Any effect that the expectations of the researcher might have on the measurement and recording of the dependent variable. Uncontrolled experimenter bias threatens the validity of research.
- experimenter effects
- Any behavior of a researcher that might affect the behavior of participants or the measurement of dependent
variables. Experimenter expectancies can create powerful experimenter effects.
- experimenter expectancies
- Expectations of the researcher about the relationship between the variables being studied. Experimenter expectancies may affect the accuracy of the observations, especially
when judgments are required.
- experimenter reactivity
- Any action by the researcher other than the manipulation of the independent variable that tends to influence
participants' responses. A type of experimenter
- exploratory research
research designed to investigate feasibility and to generate, rather than
- external validity
- Extent to which the results of a study accurately indicate the true nature of a relationship between variables. If a study has external validity, the results are said to be
- extraneous variable
- Any variable other than the independent variable that might affect the dependent measure. Extraneous variables are potentially confounding and must be controlled.
- extraneous variance
- Variability in scores on the dependent measure that can be accounted for by the effects of extraneous variables.