experimental research
designed to establish a true cause-and-effect relationship
laboratory research
conducted in the tightly structured conditions of a lab
field research
conducted where people actually live, work, and play in the real world of classrooms, worksites, and communities
internal validity
the extent to which the observed effect the independent variable on the dependent variable are real and not caused by extraneous factors
external validity
involves the ability to generalize study results to other groups anf settings beyong those in the current study
threats to internal validity
any aspect of a study that causes one to question if the results are true and accurate
history effect
when events occur outside of a research study between pretest and posttest that could affect participants in such a way as to have an impact on the dependent variable
control group
in experimental research, a group of participants exactly like the treatment group in every way possible except they recieve no treatment
experimental group
the group recieving the treatment
maturation effect
changes seen in subjects are a rsult of the time that has elapsed since the study began and not any program effects
a measurement taken to obtain the status or level of a variable prior to initiating a study
learning techniques or strategies for taking a test that improve one’s test scores
testing effect
learning that results from taking a prestest causes one to do better on a posttest
selection bias
threat to validity that occurs when study participants are selected in a nonrandom manner
morality effect
to threat to validity from an attrition of study participants
Hawthorne effect
occurs when participants’ attitudes toward being involved in a study affects the way they behave
placebo effect
differences caused by participants’ expectations instead of any provided treatment
diffusion effect
occurs when the treatment being applied to one group spills over to or contaminates another group
location effect
occurs when there are differences in the location where interventions take place
implementation effect
a threat to internal validity that occurs when those respondsible for implementing the experimental treatment inadvertently introduce inequality or bias into the study
selection treatment interaction
external threat to validity that concerns the ability of a researcher to generalize the results of a study beyond the groups involved in the study due to the way the study groups were selected
study population
those in the population who are accessible to the researcher, who had the potential of being selected for the study, and to whom the results can be generalized
those individuals in the universe that are specified by time and place
setting treatment interaction
a threat that concerns the extent to which the enviromental conditions or setting under which an experiemental study was conducted can be duplicated in other settings
history treatment interaction
a threat to external validity that develops :when the researcher tries to generalize findings to past and future situations”
analysis of convariance
a statisicial technique that can be used to control for initial group differences