Inquizitive 4

Kumail reads the headline "Half of Americans show road rage," and he wants to examine whether this frequency claim has strong external validity. What would have been the best sample for the study to attain external validity?

a cross section of American drivers representing all genders; urban, suburban, and rural populations; and all age groups

In any claim, using __________ can help improve __________ validity because it ensures that the variable(s) of interest are assessed well.

a reliable measure -------- construct

In any claim, using _______ can help improve ___________ validity because it allows for the generalization of results.

a representative sample --- external

A researcher had two separate groups of participants drink either one glass of red wine or no red wine, in order to find out whether drinking red wine can reduce the stress levels that participants record on a self-reported stress measure. Identify the independent variable in this example.

amount of red wine

In a frequency claim, using __________ can help improve __________ validity because the range of values is likely to include the true population value.

confidence intervals ------ statistical

Professor Nakum designs an experiment to test the effect of word familiarity on memory. She creates three lists with 30 words each: common, uncommon, and nonsense words. Participants study one of the lists for five minutes, solve math problems for five minutes, then write all the words they recall from the list. The participants' score is the number of words they correctly recalled. number of words on the lists

constant

Professor Nakum designs an experiment to test the effect of word familiarity on memory. She creates three lists with 30 words each: common, uncommon, and nonsense words. Participants study one of the lists for five minutes, solve math problems for five minutes, then write all the words they recall from the list. The participants' score is the number of words they correctly recalled. time allotted for solving math problems

constant

JoAnn is interested in the availability of mental health care for emergency room patients. She has a limited amount of time with each participant, as patients are rapidly moved in and out of the emergency room. She decides to use a shorter, less reliable measure of mental health care availability in favor of getting as many participants as possible, enabling her to reach people of many different backgrounds, illnesses, and injuries. In this example, JoAnn is sacrificing ______ validity to strengthen __________ validity.

construct ---- external

A variable is operationalized well.

construct validity

Paola reads a journalistic report with the headline "Most Americans say they support gender equality." She has several questions about the validities of the study covered in the article. Identify each of Paola's questions as addressing statistical, construct, or external validity. How well did the researcher measure the variable?

construct validity

A recent study investigated whether watching cat videos online causes viewers to have less stress. The study recruited a diverse sample of online participants and had them watch a video of kittens. The participants were then given a 5-item questionnaire about their current stress levels. Participants seemed to have less stress after watching the video, and a statistical test showed a strong effect. Which types of validity which were reasonably met?

construct, external, statistical

Professor Nakum designs an experiment to test the effect of word familiarity on memory. She creates three lists with 30 words each: common, uncommon, and nonsense words. Participants study one of the lists for five minutes, solve math problems for five minutes, then write all the words they recall from the list. The participants' score is the number of words they correctly recalled. number of words correctly recalled

dependent variable

The measured variable in an experiment is called the ____ ____ and the manipulated variable in an experiment is called the ______ _____

dependent variable --------- independent variable

To test a causal claim, scientists will often sacrifice ____ validity in exchange for maximizing ________ validity.

external ---- internal

Blessing is conducting an experiment on how children respond to different types of math problems. She gives some children problems with pictures and other children problems without pictures, and she plans to measure which group gets more problems right. Blessing wants to be certain that her manipulation of the types of problems is clear and is the cause of any differences between the groups. She also wants to ensure that her statistical conclusions will be accurate. Identify the validities as a lower priority in the context of this experiment.

external validity

Paola reads a journalistic report with the headline "Most Americans say they support gender equality." She has several questions about the validities of the study covered in the article. Identify each of Paola's questions as addressing statistical, construct, or external validity. How did the researcher choose the participants?

external validity

Paola reads a journalistic report with the headline "Most Americans say they support gender equality." She has several questions about the validities of the study covered in the article. Identify each of Paola's questions as addressing statistical, construct, or external validity. How well do the participants reflect the population of interest?

external validity

Results generalize to other people and situations.

external validity

A recent newspaper headline stated that 1 in 4 teens in the United States is concerned about climate change. You read the article and find that a study randomly surveyed a sample of teens from the Midwest via phone, and the researchers operationalized concern for climate change as "feeling afraid, angry, or guilty about climate change." What type of validity may be insufficient in this study?

external validity The researchers only sampled teens from the Midwest, which is likely not representative of the whole United States.

Monique has created an experiment to test whether napping during the day improves productivity in the evening. She has one group of participants take a half-hour nap, one group take an hour-long nap, and one group take no nap at all. She then asks all participants to evaluate their productivity by writing down the number of tasks they have accomplished. levels of the independent variable

half-hour nap, hour-long nap, and no nap

Monique has created an experiment to test whether napping during the day improves productivity in the evening. She has one group of participants take a half-hour nap, one group take an hour-long nap, and one group take no nap at all. She then asks all participants to evaluate their productivity by writing down the number of tasks they have accomplished. independent variable

how long participants nap

Aaron is conducting an experiment in which he randomly assigns athletes recovering from grade 1 muscle strains to two different forms of physical therapy, in order to see which therapy produces the shortest recovery time. In this example, type of physical therapy is the _________ variable. In this example, recovery time is the _______ variable. This study would likely result in a ______ claim.

independent --- dependent --- causal

Professor Nakum designs an experiment to test the effect of word familiarity on memory. She creates three lists with 30 words each: common, uncommon, and nonsense words. Participants study one of the lists for five minutes, solve math problems for five minutes, then write all the words they recall from the list. The participants' score is the number of words they correctly recalled. type of word list

independent variable

A recent study investigated whether watching cat videos online causes viewers to have less stress. The study recruited a diverse sample of online participants and had them watch a video of kittens. The participants were then given a 5-item questionnaire about their current stress levels. Participants seemed to have less stress after watching the video, and a statistical test showed a strong effect. Which types of validity were not established in this study?

internal

What type of validity is not prioritized when testing association or frequency claims, but is when testing causal claims?

internal Because neither association nor frequency claims attempt to say that one variable is the cause of change in another, they cannot be evaluated for internal validity.

Ayomide is reading a recent article with the headline "School lunches make kids overweight." The article cites a study comparing children at two schools. At the school with the lower obesity rate, only a few children eat school lunch. The other school has a greater percentage of obese children, and most of these children eat school lunch. The article doesn't mention that the school with the higher obesity rate is in an area where most people are below the poverty line, nor does it mention that poverty can be a major factor in obesity. What validity is threatened by the potential confound of poverty?

internal validity

when the variables were measured or manipulated well, and that they represent the concepts they're meant to represent.

internal validity

The point estimate

is the percentage that estimates a value in the population of interest. This is relevant to statistical validity because the point estimate ensures that results are numerically sound.

Monique has created an experiment to test whether napping during the day improves productivity in the evening. She has one group of participants take a half-hour nap, one group take an hour-long nap, and one group take no nap at all. She then asks all participants to evaluate their productivity by writing down the number of tasks they have accomplished. dependent variable

productivity

In a causal claim, using _____ can help improve ____________ validity because it helps control for potential differences between participant groups.

random assignment ----- internal

Solveig is testing whether a new experimental drug she designed can improve immune functioning. She recruits participants for a clinical trial and randomly assigns them to either a treatment group, in which they receive the drug, or a control group, in which they receive a placebo. After several weeks, she measures the differences between the two groups' immune functioning via blood test. Solveig announces that the treatment group had better immune functioning after the trial and claims that her drug was effective. Though the immune functioning between the two groups was different, that difference was not statistically significant. Assuming that Solveig's drug is effective, which type of validity might be insufficient in this study?

statistical Because the difference was not statistically significant, it's possible that the difference between the two groups may have occurred by chance, which is a serious issue with Solveig's study.

Paola reads a journalistic report with the headline "Most Americans say they support gender equality." She has several questions about the validities of the study covered in the article. Identify each of Paola's questions as addressing statistical, construct, or external validity. what is the confidence interval?

statistical validity

Paola reads a journalistic report with the headline "Most Americans say they support gender equality." She has several questions about the validities of the study covered in the article. Identify each of Paola's questions as addressing statistical, construct, or external validity. what is the point estimate

statistical validity

Results are accurate and reasonable and have been replicated.

statistical validity

A study has statistical validity

when the numbers and calculations reported by the research are reliable and can be repeated across multiple studies.

A study has external validity

when the results apply to different contexts and situations, and to the population researchers are interested in examining.

A study has construct validity

when the variables were measured or manipulated well, and that they represent the concepts they're meant to represent.

A study has internal validity

when there are no alternative explanations for the relationship between two variables.

Identify the false statements about the statistical validity of frequency claims.

- A point estimate gives us the exact value of the population of interest. - A confidence interval gives us information other than the margin of error of the estimate.

Identify the true statements about the statistical validity of frequency claims.

- A point estimate in a frequency claim is usually expressed as a percentage. - A confidence interval indicates the precision of a point estimate.

Identify the false statements about prioritizing validities.

- A study without external validity is not important or meaningful. - Researchers must satisfy every type of validity in every study they conduct.

Identify the true statements about prioritizing validities.

- Scientists weigh the pros and cons of different research choices to determine which validities to emphasize. - In experiments, internal validity is often the first priority.

Identify the true statements about the statistical validity of association claims.

- Studies that have been conducted more than once have better statistical validity. - A study that finds a 55% difference between groups demonstrates a stronger association than a study that finds a 10% difference between groups. - Confidence intervals reflect the precision of the estimated association.

Identify the false statement(s) about the statistical validity of association claims.

- Studies with larger samples have wider confidence intervals.

Which of the following would a researcher need to demonstrate in order to make the claim that exercise decreases stress? needs to demonstrate

- The amount of exercise goes up as stress goes down. - Exercise came before the measurement of stress. - There are no other explanations for why exercise is linked to stress.

Which of the following would a researcher need to demonstrate in order to make the claim that exercise decreases stress? dont need to demonstrate

- There are no stressed people who exercise. - The association between exercise and stress in the study generalizes to the whole population of interest.

Blessing is conducting an experiment on how children respond to different types of math problems. She gives some children problems with pictures and other children problems without pictures, and she plans to measure which group gets more problems right. Blessing wants to be certain that her manipulation of the types of problems is clear and is the cause of any differences between the groups. She also wants to ensure that her statistical conclusions will be accurate. Identify the validities as higher in the context of this experiment.

- statistical validity - construct validity - internal validity

Monique has created an experiment to test whether napping during the day improves productivity in the evening. She has one group of participants take a half-hour nap, one group take an hour-long nap, and one group take no nap at all. She then asks all participants to evaluate their productivity by writing down the number of tasks they have accomplished. levels of the dependent variable

0, 3, 5, or 7 tasks