Internal Validity
This threat to internal validity occurs when participants take the same test or measure multiple times during a study and the repeated testing may change how they score on the test.
What is threat due to testing?
This type of threat to external validity is humorously implied as “even the rats were white males” under the lab setting of scientific research.
A: What is interaction of causal relationship with units?
This is missing in a one-group pre-test/post-test design.
What is a control group?
A validity that is strengthened by random sampling.
What is external validity?
Threat that occurs in an independent groups design when participants in one level of the independent variable are systematically different from participants those at the other level.
What is selection?
A threat that occurs when it is unclear whether a change in the treatment group is caused by the treatment or an event that affects everyone or almost everyone in the group.
What is threat due to history?
Yes, I accept that the youth job-training program increases the likelihood of being employed immediately after graduation. But what does it do to adaptivejob skills such as punctuality or the ability to follow orders?
What is Interaction of Causal Relationship with outcomes?
A study design in which there are two or more interventions that are crossed to examine each possible combination.
What is a factorial design?
A validity that is strenthened by random assignment.
What is internal validity?
A threat to internal validity that occurs when an observed change in an experimental group could have occurred more or less spontaneously over time.
What is threat of maturation?
This is a problem when researchers try to make causal inferences, but they can’t be sure which variable occurred first.
What is Ambiguous temporal precedence?
An advanced breast cancer patient asks whether a newly developed treatment that improves survival in general would improve her survival in particular, given her pathology, her clinical stage, and her prior treatments
What is external validity
This is the specific way in which a construct of interest is measured or manipulated as a variable in the study.
What is the operational definition?
An indication of how well a variable was measured or manipulated in a study
What is construct validity?
A threat to internal validity that occurs when a measuring instrument changes from previous uses.
What is instrumentation?
Researchers are evaluating an 3-wk intervention to reduce stress in families immediately after the death of a loved one. They measure stress before and after the intervention and find that their stress goes down over time. Researchers claim that the intervention reduced family members’ stress, but actually it’s normal for people who are stressed during a crisis to return back to calmer state after some time.
What is regression to the mean?
Population validity and ecological validity are types of this kind of validity.
What is external validity?
A study that is similar to an experiment, but the researchers don’t have full experimental control.
What is a quasi-experiment?
A variable, that depending on its level, changes the relationship between the intervention and the outcome.
What is a moderator?
Researchers are doing a study on self esteem. They give participants a treatment that involves pointing out all their weaknesses, then pointing out all their strengths and talking about how their strengths will help them succeed past their limitations. Researchers found that people's self esteem goes up, and conclude that the treatment helped them. BUT lots of participants dropped out.
What is threat due to attrition?
In a within-groups design, a threat to internal validity in which exposure to one condition changes participants responses to a later condition.
What is order effect?
Authors of a study claim that a mindfulness-based stress reduction intervention reduced stress in cancer patients. However, the final sample included 98% white women with breast cancer. A reviewer might identify this threat to external validity based on their claim
What is the threat of Interaction of the causal relationship with units.
By ensuring equal distribution of potential confounding variables across groups, this helps attribute observed effects to the intervention.
What is randomization?
Highly selected samples, lack of diversity in participant characteristics, and artificial settings or conditions that don't reflect the real world.
What are threats to external validity
The three things that are necessary to make a causal claim.
What are covariance, temporal precedence, and internal validity?