Question 1

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) Experimental design
B) Quasi-experimental design
C) Nonexperimental design
D) Meta-analysis

Accepted Answer

The researcher is using an experimental design because there are randomly assigned groups, including a control group, to test the effects of different treatments.

Question 2

Which of the following would most accurately determine causality?
A) An experiment in which researchers manipulate the dependent variable
B) An experiment in which researchers manipulate multiple independent variables
C) An experiment in which researchers study the variables in chronological order
D) An experiment in which researchers produce results that cannot be duplicated

Accepted Answer

C

Question 3

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?
A) The oncologist did not use the most reliable research techniques.
B) The oncologist knows it is possible that other factors contributed to elevated cancer rates.
C) More evidence is needed for the oncologist to state the findings as a certainty.
D) Follow-up studies by other oncologists are needed to validate the findings.

Accepted Answer

The oncologist acknowledges that other factors could have contributed to the elevated cancer rates, hence stating it as a probability rather than a certainty.

Question 4

Which type of variable confuses the effect of the independent variable on the dependent variable?
A) Control variables
B) Extraneous variables
C) Random variables
D) Within-group variables

Accepted Answer

Extraneous variables are those that are not of interest in the study but can affect the results by confounding the effect of the independent variable on the dependent variable.

Question 5

Which factor would most likely distort the relationship between the independent and dependent variables, producing biased results?
A) Use of random assignment
B) Manipulation of the independent variable
C) Use of between-groups design
D) Presence of an extraneous variable

Accepted Answer

The presence of an extraneous variable can introduce bias by affecting the dependent variable, thus distorting the relationship between the independent and dependent variables.

Question 6

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?
A) Effects of selection
B) Instrumentation
C) Testing
D) Maturation

Accepted Answer

Maturation is a threat to internal validity in this study because adolescents naturally undergo significant developmental changes that could affect self-esteem over time, independent of hearing loss.

Question 7

A researcher who uses a double-blind experimental design is most likely trying to reduce which threat to external validity?
A) Effects of selection
B) Experimenter reactivity
C) Treatment and setting interactions
D) Treatment and history interactions

Accepted Answer

A double-blind design is used to reduce experimenter reactivity, which is when the experimenter's expectations or behavior influence the outcome of the study.

Question 8

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?
A) Type II error
B) Hawthorne effect
C) Instrumentation error
D) Double-blind experimental design

Accepted Answer

The Hawthorne effect refers to the phenomenon where individuals modify their behavior in response to being observed or knowing they are part of a study, leading participants to report healthier behaviors such as higher water intake and lower consumption of juices and sodas.

Question 9

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?
A) Cross-sectional study
B) Retrospective design
C) Follow-up study
D) Trend study

Accepted Answer

A follow-up study, also known as a longitudinal study, tracks the same individuals over time, allowing the researcher to observe changes in vision associated with screen time in heavy gamers.

Question 10

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) Ex post facto design
B) Crossover design
C) Longitudinal design
D) Cross-sectional design

Accepted Answer

An ex post facto design is used to investigate the potential causes of an observed effect by examining existing conditions or events that have already occurred, such as the change in road signs before the increase in accidents.

Question 11

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) Random assignment
B) Bias selection
C) Random sampling
D) Manipulation control

Accepted Answer

Random sampling is used to select participants from a population in a way that each individual has an equal chance of being chosen, which helps control for extraneous variables by ensuring a representative sample.

Question 12

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) Cross-sectional
B) Cohort comparison
C) Retrospective
D) Longitudinal

Accepted Answer

A retrospective study looks back at events that have already occurred, such as analyzing patient medical histories to study the transmission and development of influenza.

Question 13

Randomization is one way researchers can control for extraneous variables.

Accepted Answer

Randomization helps ensure that extraneous variables are evenly distributed across treatment groups, reducing their potential impact on the outcome.

Question 14

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

Accepted Answer

A between-groups design compares different groups of participants, while a within-subjects design would be used to compare the same participants' blood pressure before and after the therapy.

Question 15

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.

Accepted Answer

Allowing participants to choose their study group can introduce selection bias, affecting the internal validity of the study, although it may align with ethical considerations regarding autonomy and human rights.

Question 16

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

Accepted Answer

Longitudinal designs track the same subjects over time, allowing researchers to observe changes and infer causal relationships, unlike cross-sectional designs which provide a snapshot at one point in time.

Question 17

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.

Accepted Answer

Informing participants about random assignment does not create selection bias; it is an ethical requirement to ensure informed consent. Selection bias occurs when the process of selecting participants leads to a non-representative sample, not from informing them about random assignment.

Question 18

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.

Accepted Answer

The answer of A researcher is designing an experiment to...

Question 19

Describe the relationship between construct validity and external validity.

Accepted Answer

The answer of Describe the relationship between construct validity and...

Question 20

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

Accepted Answer

The answer of Describe two threats to internal validity that...

Quiz 6: Key Principles of Quantitative Designs

Which of the following would most accurately determine causality?

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

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?

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

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?

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 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?

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?