In an experiment designed to investigate the effect of internet-based instruction in classroom setting, some instruction was missed because of a power failure at the school.
What is HISTORY THREAT?
100
One of the ways to reduce this bias is by using standard questionnaires and training all interviewers.
What is interviewer bias?
100
Confounding is more likely to occur in this type of study.
What is observational study?
100
This bias in a survey can occur when an individual for the sample can't be contacted or refuses to cooperate.
What is response bias?
100
You would expect this effect if the interviewers were aware of the disease status of the study subjects.
What is interviewer bias?
200
The performance of second graders in a learning experiment begins decreasing after 1 hour because of fatigue.
What is MATURATION THREAT?
200
This potential bias could have been introduced if you found out that those who interviewed cases took 30 minutes longer on average than those who interviewed controls.
What is information bias?
200
A confounding variable has this type of association with the outcome.
What is a causal association?
200
Tendency of people to give socially desirable answers is an example of this bias.
What is measurement bias?
200
An association between an exposure and an outcome that is induced, strengthened, or weakened by a third variable.
What is confounding?
300
Three investigators for an instructional experiment administered a post-test with different instructions as well as different procedures.
What is INTRUMENTATION THREAT?
300
The best way to prevent bias from loss to follow-up in a study is by maintaining this follow up rate.
What is higher than 80%?
300
This strategy is used to control for the confounding effect.
What is stratification?
300
In an experiment involving mathematical skill performance, subjects grouped because of poor pre-test math scores show considerably greater gain than the groups who scored average on the pre-test.
What is STATISTICAL REGRESSION?
300
In a physical activity experiment designed to determine the effect of various exercises, subjects who find the exercise tasks most difficult decide to stop participating.
What is ATTRITION?
400
The experimental group in a reading experiment consisted of a high-ability readers, while the comparison group was an average ability class.
What is SELECTION THREAT?
400
In case-control study, if both cases and controls have more or less equal difficulty in remembering past exposures accurately, it will lead to this.
What is nondifferential misclassification?
400
This occurs when the categories of the confounding variables are too broad or when the confounding variables remain unaccounted for.
What is residual confounding?
400
Selection bias does not occur in this type of study.
What is RCTs or prospective cohort studies?
400
Using blinded studies, for subjects and/or researchers helps in avoiding this.
What is differential misclassification of outcomes?
500
In an intervention experiment relating to diet and nutrition, participants in the experimental and comparison groups discuss different methods they learned about proper dieting.
What is CONTAMINATION THREAT?
500
This is a method to avoid potential bias when sampling in a survey.
What is the use of simple random sampling?
500
This is an extreme case of confounding where the confounding effect results in an inversion of the direction of the association.
What is qualitative confounding?
500
This type of confounding may lead to an underestimation of the true strength of association.
What is negative confounding?
500
In an experiment in which performance on an interpretation test is the dependent variable, an administered pre-test cues the subjects about the post-test.