Question 1

When a change in the dependent variable could be due to the researcher's hypothesis or the participant's hypothesis, __________ is a threat to internal validity.

Accepted Answer

Demand characteristics refer to the cues or clues present in the research design that unintentionally communicate to participants what the researcher expects to find or how they should behave. This can lead to changes in the dependent variable that are not due to the independent variable but rather to the participants' attempts to please the researcher or meet their expectations. Therefore, demand characteristics threaten internal validity when changes in the dependent variable could be due to the researcher's or the participant's hypothesis. Diffusion of treatments refers to participants in one group being influenced by the treatment received by participants in another group, which is a threat to internal validity in experimental designs. Instrumentation refers to changes in the measurement instrument or procedure that lead to changes in the dependent variable, which is a threat to internal validity in both experimental and non-experimental designs. Placebo effect refers to improvements in the dependent variable due to receiving a treatment that has no active ingredients or effects, which is a threat to internal validity in experimental designs that involve a placebo group. However, placebo effect is not related to the researcher's or the participant's hypothesis.

Question 2

Let us pretend that the U.S.Department of Agriculture does regular surveys on mature Americans to see what concerns they have with foodborne illnesses.You hear on the news one night that mature Americans are now 50 times more likely to worry about Mad Cow disease than they were five years ago.You happen to remember that there was an outbreak of Mad Cow disease last year at around the same time the data were collected).It is possible that the increase in concern over Mad Cow disease is partially due to the recent outbreak.This is an example of __________ being a threat to internal validity.

Accepted Answer

History refers to external events that may occur during the study that could affect the outcome. The outbreak of Mad Cow disease is an external event and may have influenced the responses of mature Americans in the survey, making it a threat to internal validity.

Question 3

In a __________ study, the participant has no knowledge of which group he or she has been assigned to, although the researcher knows.

Accepted Answer

In a single blind study, the participant is not aware of which group they have been assigned to, but the researcher knows. This helps to reduce bias and increase the validity of the results. The other options listed (double blind, dual blind, and mono blind) are not commonly used or recognized terms in research methodology.

Question 4

In a ___________ study, neither the participant nor the researcher knows which group a particular participants has been assigned.

Accepted Answer

A double-blind study is one in which both the participant and the researcher are unaware of which group a particular participant has been assigned to. This helps to eliminate bias and increase the validity of the study.

Question 5

If you and a friend watched an episode of Family Guy separately and counted the number of violent acts, you are likely to get different counts.Which threat to internal validity explains these results?

Accepted Answer

The difference in counts could be due to differences in how each person is measuring or identifying a "violent act." This is an issue with instrumentation, or the consistency and accuracy of the measurement tool being used.

Question 6

When a change in the dependent variable could be due to the participant's expectation that change will occur, __________ is a threat to internal validity.

Accepted Answer

The placebo effect occurs when participants experience a change in dependent variable due to their expectation that change will occur, even if they did not receive an active treatment. This can be a threat to internal validity as it can make it difficult to determine if the treatment itself caused the change in the dependent variable.

Question 7

Which of the following statements regarding threats to internal validity is correct?

Accepted Answer

Threats to internal validity can be controlled for with research designs and techniques such as randomization, control groups, and counterbalancing. These techniques aim to minimize the effects of extraneous variables and increase the likelihood that any observed effects are due to the independent variable. While it is not possible to completely eliminate all threats to internal validity, researchers can take steps to reduce their impact.

Question 8

It happens occasionally that a student who is in one of our classes has previously taken the class from another instructor.The repeater students will comment that the class is so much easier with us as instructors.Now, we might want to believe that we are such great instructors that student learning the dependent variable) has drastically improved because of us the independent variable).However, which threat to internal validity better explains the increase in student learning?

Accepted Answer

Testing is the correct answer because it refers to the effect of taking a test on the scores of subsequent tests. In this context, students who have previously taken the class (and presumably its tests and assignments) may perform better the second time around not necessarily because of improved teaching methods, but because they are already familiar with the material and the types of questions they might be asked. This familiarity can lead to an increase in student learning outcomes that is actually due to prior exposure to the test material rather than the instructional quality.

Question 9

Many colleges and universities offer a freshman seminar class to prepare students for college life.Colleges put a great deal of money into these classes and want to know if the freshman seminar classes the independent variable) have an influence on the students' attitudes and behaviors the dependent variable).This is commonly measured by conducting a survey at the end of the first year about information covered in the classes.Which of the following threats to internal validity could influence survey results?

Accepted Answer

Maturation refers to the processes within participants that may change over time, such as growing older, gaining more experience, or changing attitudes and behaviors simply because they are in college, not necessarily because of the freshman seminar classes. This natural development can influence survey results, making it difficult to attribute changes solely to the seminar classes.

Question 10

Think of a research experiment designed to test which diet is best at helping people lose weight-Atkins, Jenny Craig, or Weight Watchers.The results could show that the average weight lost on Atkins was 6 pounds per week and on Jenny Craig and Weight Watchers was 2 pounds per week.It is important to ask yourself if participants are dropping out of a study in a manner that might influence the results to determine if __________ is a threat to internal validity.

Accepted Answer

The answer of Think of a research experiment designed to...

Question 11

You have just learned of survey results conducted by your university on the drinking behaviors of the college campus.Wondering about the results, you ask yourself the following questions: how were participants selected, were participants selected depending on if they lived on- or off-campus, were all the participants in a sorority or fraternity, were non-traditional age students included in the survey, and were men and women equally sampled? These types of questions indicate that you are concerned about what threat to internal validity?

Accepted Answer

The questions about how participants were selected and whether certain subgroups were over or underrepresented suggest concern about the threat of selection bias, which can reduce internal validity. Selection bias occurs when the process of selecting participants results in a sample that is not representative of the population being studied, leading to inaccurate or biased results.

Question 12

Which of the following statements accurately describes the use of double blind studies?

Accepted Answer

Double blind studies are preferred because they reduce the threats to internal validity by minimizing experimenter bias and participant bias. The researcher can still have access to participant data without compromising the blinding aspect of the study. Single blind studies do not eliminate experimenter bias as the researcher is aware of which group the participant belongs to.

Question 13

When a change in the dependent variable could be due to participants' familiarity with the test, __________ is a threat to internal validity.

Accepted Answer

Testing is a threat to internal validity when participants' familiarity with the test may affect the results of the dependent variable. This is the case when participants take the same test multiple times, and their previous exposure to the test may affect their performance on subsequent administrations.

Question 14

Think about the American Idol example in the Are You Equipped? section at the beginning of the chapter.By the judges giving their expert opinions on contestants' performances, they are communicating to the audience how we should vote.Thus, __________ is a threat to internal validity.

Accepted Answer

The judges' expert opinions may create a demand characteristic in the audience, causing them to alter their voting behavior based on the judges' feedback, which threatens the internal validity of the voting process.

Question 15

When a change in the dependent variable could be due to changes in how the dependent variable was measured, _________ is a threat to internal validity.

Accepted Answer

Instrumentation refers to changes in how a dependent variable is measured over the course of a study, which can threaten its internal validity as it is unclear whether any changes in the variable are due to the treatment or due to changes in measurement. Attrition refers to participants dropping out of a study, testing refers to repeated measurement of the same variable influencing results, and diffusion of treatment refers to the spread of a treatment or intervention to participants who were not intended to receive it.

Question 16

The authors of your textbook discussed a study on teaching practices in which their two classes where communicating with one another and influenced the results of the study.In this scenario, which of the following was a threat to internal validity?

Accepted Answer

The diffusion of treatment is a threat to internal validity in this scenario because the two classes were communicating with one another and potentially sharing information about the teaching practices being studied. This means that the treatments may have diffused between groups and influenced the results, making it difficult to determine the true effects of the teaching practices being studied. Attrition refers to participants dropping out of a study, testing refers to participants being affected by taking the same test multiple times, and instrumentation refers to changes in the measurement tool used in a study. While these factors may also be threats to internal validity in other scenarios, they are not relevant to the study described in this question.

Question 17

When a change in the dependent variable could be due to participants in one group talking to participants in another group, __________ is a threat to internal validity.

Accepted Answer

Diffusion of treatment occurs when participants in one group talk to participants in another group and inadvertently share information or treatments. This can affect the dependent variable and is a threat to internal validity. Attrition is the loss of participants over time and can also be a threat to internal validity. Testing refers to the effect of taking a test multiple times, and instrumentation refers to the potential for changes in the measurement instruments to impact the dependent variable. While both attrition and instrumentation can be threats to internal validity, they are not directly related to participants in different groups interacting with each other.

Question 18

Have you ever played a video game breaking the all-time high score only to find that you were never able to duplicate that performance? This is an example of _________, which is a threat to internal validity.

Accepted Answer

Regression to the mean occurs when extreme scores or values are more likely to move towards the average on subsequent attempts. In the scenario given, the initial high score was likely due to chance and not necessarily reflective of the individual's true ability. Therefore, on subsequent attempts, the individual is more likely to score closer to their true average performance. This is a threat to internal validity as it can affect the accuracy and validity of the results when studying a particular variable or phenomenon.

Question 19

In the Are You Equipped Now at the end of the chapter, the authors of the textbook identified ______ threats to internal validity?

Accepted Answer

The authors identified six threats to internal validity in the Are You Equipped Now section at the end of the chapter.

Question 20

Imagine a study where participants were given Jell-O shots to consume before participating in experiments where reaction time was measured.However, to the participants' surprise, the Jell-O shots were not made with alcohol.When the participants were debriefed and told that the Jell-O contained no alcohol, some participants refused to drive home until they had sobered up.The participants' responses indicate that __________ was a threat to internal validity.

Accepted Answer

The participants' reactions indicate that they expected the Jell-O shots to contain alcohol and experienced the placebo effect when they did not. This is a threat to internal validity as it can affect the accuracy of the results obtained from the experiments.

Quiz 9: Controls and Threats to Interval Validity