a) threatens internal validity when events occu between the oretest and posttest of a reasearch studythat could effect participants in such a way as to impact the dependent variable

b) the best way to control for history efffect is to use a control group that has no exposure to any environmental factors that may a play a part in skewing results.

a) occurs when changes are seen in subjects because of the time that has elapsed sinced the study began and that may be the result of any program effects.

b) using a control group would work for comparing the two groups since the control group would be expected to change naturally on its own

a) any diferences seen from baseline to posttest.

b) use a control group that does not recieve any pretesting will reduce threat to internal validity

a) thrat to validity that occurs when study participants are selected in a nonrandom manner

b)recruiting volunteers and then randomly assigning them to groups instead of allowing them to self-select a group, matching participants on selected characteristics and then randomly assigning them to groupsmay also reduce bias, or pretesting groups of measures of the dependent variable to make sure there are no pretreatment differences.

a) occurs when intact groups are used and the groups vary on their maturation levels

b) pretesting and/or prescreening groups on maturity levels is a way to avoid this threat to validity

a) occurs when participants are selected on the bias of their extremely high or low scores

b) follow a random sample addressing full range of scores

a) threat from an attirtion of study participants

b) oversampling and using large grou size is way to overcome small group size. To help with study participant dropu-outs using incentives to encourage them can help.

a) when a participants attitudes towards being involved in a study effect the way they behave

b) researcher may try to provide the control group with some type of special treatment that is comparable to the experimental group but would not have a direct impact on the dependent variable. Another way is to keep participants from knowing that they are taking partin a study or are being observed.

a) caused by the participants expectations rather than by any provided treatment.

b) reseracher can try to to make sure that both the control and experimental groups recieve the same information (or drug) so that both groups will have the same information. Another way is to give both groups s litle information as possible so as to reduce any expectations.

a) when the treatment applied to one group spills over or contaminates anotther group

b) if possible reserachers should try to keep the control group away from experimental group.

a) occurs when there are differences in the locations where interventions take place

b) make the locations the same for all participants. Researcher should do eerything possible to minimize locaion differences that could impact dependent variable.

a) the individual or individuals responsible for implementing the experimental treatment and the possibility that they may inadvertently introduce inequality or bias into the study

b) whenever possible have someone other than the program director (someone neutral) present the program. Another way is to have a neutral observer watch the presenter with specific instructions to look for ways in which the two groups are being treated differently.

a) concerns the ability of the researcher to generalize the results of the study beyond the groups involved in the study

b) boaden generalizations by using a "study population" instead of an intact group and/or use a larger study group

a) this threat concerns the extent to which the environmental conditions or setting under which an experimental study was conducted can be duplicated in other settings.

b) whatever is learend form one site should not genralized to another site.

a) when researher tries to genralize the findings to pas and future situations

b) make sure the resarcher is generalizing the most effective time frames.