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.
- E-mail
- See
electronic mail.
- empirical
- Based on observed data. For example, a relationship between
variables is empirically established if it has been observed to
occur.
- empiricism
- System of knowing that is based solely on observation of the
events.
- enumerative data
- Synonymous with
nominal data.
- 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.
- ethology
- The study of organisms in their natural environment.
-
evaluative biases of language
- 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
- See
ex-post-facto fallacy.
- ex-post-facto study
- See
ex-post-facto design.
- exact replication
- Repeating a study by using exactly the same procedure used
in the original study. See also
replication.
- experiment
- 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 group.
- 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
- See
experimental level of constraint.
- experimental variance
- Variability among the group means in a research study.
- experimentation
- 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 manipulation 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 bias.
- exploratory research
- Low-constraint research designed to investigate feasibility
and to generate, rather than test, hypotheses.
- 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 generalizeable.
- extraneous variable
- Any variable other than the independent variable that might
affect the dependent measure. Extraneous variables are potential
sources of 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.