Term
| Internal Validity: A History Effect |
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Definition
1. History effect threatens internal validity when events occur between the pretest and posttest of a research study that could affect participants in such as way as to impact the dependent variable (cited by Cottrell & McKenzie, 2005, p.164).
2.In order to address this situation, a researcher can use a control group that does not have access to information that can affect the dependent variable. |
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Term
| Internal Validity: Testing |
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Definition
1. Having a pretest and posttest can affect research by giving the participants a "test-wise" perspective, allowing them to do better on the posttest due to already taking the pretest.
2. To help prevent this, using a control group that does not receive any pretesting can help eliminate this threat. |
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Term
| Internal Validity: Selection Maturation Effect |
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Definition
1.This comes about when using intact experimental groups that may vary in maturation level.
2. In order to prevent this threat, using a prescreening method to compare and contrast the participants' knowledge can help eliminate the threat. |
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Term
| Internal Validity: Hawthorne Effect |
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Definition
1. This is when the participants' attitudes toward being involved in a study affect their behavior.
2. To help protect against this threat, the researcher can provide the control group in the experiment with a special treatment that is comparable but not exact same as the experimental group. This prevents impact on the dependent variable. |
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Term
| Internal Validity: Location Effect |
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Definition
1. This happens when the locations of the experiments and interventions have changed, which may have an effect on the experiment as a whole.
2. In order to help control for a location effect is to make the locations consistent for all who are participating in the experiment. |
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Term
| External Validity: Selection Treatment Interaction |
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Definition
1.This concerns the ability of a researcher to generalize the results of a study beyond the groups involved in the study.
2.Generalization can be harmful to an expansive group. Continuing to recognize the differences help eliminate this threat. |
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Term
| External Validity: Setting Treatment Interaction |
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Definition
1. Concerns the extent to which the experimental study was conducted can be duplicated in other settings.
2. Keeping the locations consistent, or also recognizing the differences in the locations help recognize this threat in experiments. |
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Term
| How can you increase external validity? |
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Definition
1. Consider what groups can legitimately generalize to and which you cannot generalize.
2.Making sure one can duplicate setting and historical aspects of the study can also help increase external validity. |
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Term
| What is one way you can increase internal validity within a study? |
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Definition
1. Randomly select subjects from a population
2.This allows for the ability to eliminate variance amongst the relationship of the independent and dependent variable. |
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Term
| What is one experimental design that only gives one treatment to one group? |
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Definition
1. One-Shot Case Study Design
2.This type of experiment has no randomization, no control group, and no pretesting. This allows room also for threats to the internal validity. |
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