Exam 6: Key Principles of Quantitative Designs

A research assistant takes a survey of local high school students who participate in after-school sports about whether they have suffered a concussion in the last 90 days. This is an example of which method of controlling extraneous variables?

A researcher is studying absorption rates of natural and synthetic vitamins. The researcher has three groups of randomly assigned subjects: one group that will receive the natural vitamin, one group that will receive the synthetic vitamin, and a control group that will receive a placebo. Which type of quantitative design is the researcher using?

A longitudinal design can often determine cause and effect more accurately than a cross-sectional design.

A researcher wants to see if increased screen time is associated with vision changes over time in self-reported "heavy" gamers. Which of the following experimental designs will yield the most useful data for the researcher?

Describe two threats to internal validity that are particularly problematic in longitudinal studies.

Which type of variable confuses the effect of the independent variable on the dependent variable?

A study designed to investigate an increase in traffic accidents at five major intersections finds that road signs near all of the intersections were changed during the month before the increase in accidents was observed. Which of the following experimental designs was used to obtain the findings?

A researcher would use between-groups design to compare the blood pressure of patients before and after completion of a music therapy program.

Randomization is one way researchers can control for extraneous variables.

Participants in trials of an experimental intervention are asked to track their daily food and liquid intake during the length of the trial period. Which of the following statements would best explain why the participants report higher-than-average water intake and lower-than-average intake of juices and sodas when compared with the general population?

Following extensive research and examination of multiple patients, an oncologist makes the assertion that environmental contamination is the most probable cause of elevated cancer rates observed in the population of a specific area. Which of the following statements best describes why the oncologist states the findings as a probability rather than a certainty?

An epidemiological research study about influenza that obtains data regarding the transmission and development of the illness based on patient medical histories would be considered what type of study?

A researcher who uses a double-blind experimental design is most likely trying to reduce which threat to external validity?

A researcher is designing an experiment to see whether UV light therapy or the use of an oral supplement is more effective for the treatment of vitamin D deficiency in older adults in residential care facilities. Explain whether the researcher is more likely to use random assignment or random sampling to form the test groups and provide the reasoning behind the choice.

Which of the following would most accurately determine causality?

Allowing study participants to choose which study group they are a part of protects human rights and contributes to the internal validity of the study.

Which factor would most likely distort the relationship between the independent and dependent variables, producing biased results?

A researcher is studying the effect of hearing loss on self-esteem in adolescents in grades 6 through 12. Which threat to internal validity is most likely to impact the study?

Describe the relationship between construct validity and external validity.

Informing prospective study participants that random assignment will be used to place subjects in the control and experimental groups jeopardizes the ethics of the study by creating selection bias.