Stats Quiz Questions

A researcher measures the time (in seconds) it takes a sample of 26 participants to respond to a stimulus presented on a computer screen. The standard deviation for response times is 6. In this example, what is the value for SS? a. 36 b. 150 c. 900 d. There is not enough information to answer this question

900

A researcher finds that the mean difference in productivity between employees working the morning shift (n = 16) and the night shift (n = 10) is 5.0 units, and the estimated standard error for the difference is 2.7 units. If the null hypothesis states that there is no difference in productivity, then is this result significant at a .05 level of significance? a. Yes, this result is significant b. No, this result is not significant c. There is not enough information to answer this question

No, this result is not significant

All other things being equal, as the sample size increases, what happens to the critical value for a related samples t test (or for any t test, for that matter)? a. The critical value increases b. The critical value decreases c. The critical value does not change d. It depends on the value of the test statistic

The critical value decreases

State whether the first area is bigger, the second area is bigger, or the two areas are equal: the area to the left of z = 0.80, or the area to the right of z = -0.80. a. The first area is bigger b. The second area is bigger c. The two areas are the same

The two areas are the same

Which of the following is an example of a situation in which a quasi-independent variable is used? a. random assignment can be used to assign participants to the levels of the variable b. a research design is used that meets all three criteria for demonstrating cause-and-effect c. a variable is measured that is inherent to the participant and so random assignment cannot be used d. all of the above

a variable is measured that is inherent to the participant and so random assignment cannot be used

A key objective of the literature review is to: a. describe how scientists develop questions b. develop new ideas that can be converted into a hypothesis c. use appropriate statistical software to analysis large data sets d. primarily review research that has not yet been published

develop new ideas that can be converted into a hypothesis

Which of the following research designs is used to determine the causes of behavior that help to explain why the behavior occurs? a. nonexperimental b. quasi-experimental c. experimental d. none of the above

experimental

You observe a happy couple holding hands and smiling as they walk by you. You conclude that holding hands promotes a happy relationship. What type of reasoning did you use in this example? a. deductive reasoning b. inductive reasoning c. infallible reasoning d. absolute reasoning

inductive reasoning

Science is ________ way of knowing about the world. a. one b. the only c. the best d. all of the above

one

You read about a study testing whether night shift workers sleep the recommended 8 hours per day. Assuming that the population variance of sleep (per day) is unknown, what type of t test is appropriate for this study? a. one-sample t test b. two-independent-sample t test c. related-samples t test

one-sample t test

A researcher selects two samples of 64 participants each. In the first sample the population mean was 10 and the population variance was 16. In this second sample, the population mean was 25 and the population variance was 9. Which sample will be associated with a larger standard error of the mean? a. sample 1 b. sample 2 c. None, both samples will have the same value for standard error

sample 1

Which of the following is an example of a distribution with NO variability? a. scores: 3, 5, 4, 4, 5, and 3 b. scores: 3, 3, 3, 3, 33, and 3 c. scores: 1, 2, 3, 4, 5, and 6 d. scores: 5, 5, 5, 5, 5, and 5

scores: 5, 5, 5, 5, 5, and 5

A co-worker tells an employee to close up at exactly midnight because that's when the store always closes. Which method of knowing is illustrated in this example? a. intuition b. tenacity c. empiricism d. Science

tenacity

A researcher records how long in seconds it takes a group of participants to recall a word list with low and high levels of distraction. What is the operational definition for memory in this example? a. the word list b. the operational definition is not given c. level of distraction (low, high) d. the time is takes to recall the word list

the time is takes to recall the word list

A researcher obtains z = 1.45 for a one-sample z test. What is the decision for this test at a .05 level of significance? a. to reject the null hypothesis b. to retain the null hypothesis c. It depends on whether the test is one-tailed or two-tailed

to retain the null hypothesis

A researcher conducts a study measuring differences in brain activity among rats placed on either a continuous or intermittent reward schedule. Assuming that the population variance in unknown, what type of t test is appropriate for this study? a. one-sample t test b. two-independent sample t test

two-independent sample t test

Every institution that receives federal funding for human participant research must have established the ________ to review the ethics of all research projects. a. USMC b. IRB c. APA d. IACUC

IRB

What is the z score for scores in the bottom 10%? a. 1.28 b. 2.32 c. -2.32 d. -1.28

-1.28

In psychology and across many other disciplines in the behavioral sciences, which style of communication is most often used? a. APA b. AMA c. APS d. USMC

APA

A researcher obtains z = 1.80 for a one-sample z test. What is the decision for this test at a .05 level of significance? a. to reject the null hypothesis b. to retain the null hypothesis c. It depends on whether the test is one-tailed or two-tailed

It depends on whether the test is one-tailed or two-tailed

The sample variance is an unbiased estimator of the population variance when we divide SS by df. a. True b. False

True

A researcher records the following data for the number of dreams recalled during a night of sleep for 10 college students: 3, 2, 4, 4, 3, 1, 1, 0, 2, and 0. Is the mean equal to the median in this example? a. Yes b. No; the median is larger than the mean c. No; the mean is larger than the median d. There is not enough information to answer this question

Yes

Which of the following lists the scales of measurement in order from least to most informative? a. nominal, ordinal, interval, ratio b. nominal interval, ordinal, ratio c. ratio, interval, ordinal, nominal d. ordinal, nominal interval, ratio

a. nominal, ordinal, interval, ratio

A ________ is a co-researcher or actor who pretends to be a participant in a research study for the purposes of scientific investigation. a. BFF b. placebo c. confederate d. participant

confederate

Suppose you select a sample of three people from a population of four (A, B, C, D). Which of the following samples is possible using the experimental sampling strategy? a. persons A, C, and A b. persons A, D, and D c. persons B, C, and D d. persons B, A, and B

persons B, C, and D

Based on the effect size conventions, d = 0.18 is a: a. small effect size b. medium effect size c. large effect size

small effect size

Which of the following is an example of a construct? a. age in years b. college class enrollment c. social desirability d. time in seconds

social desirability

Cohen's d is a measure of proportion of variance. a. True b. False

False

What is the central limit theorem? a. It explains that sample means will vary minimally from the population mean b. It explains that a sampling distribution of possible sample means is approximately normally distributed, regardless of the shape of the distribution in the population c. It explains that if we select a sample at random, then on average we can expect the sample mean to equal the population mean d. all of the above

It explains that a sampling distribution of possible sample means is approximately normally distributed, regardless of the shape of the distribution in the population

A null finding is a decision to retain a null hypothesis that is correct. a. True b. False

True

A one-sample t test will be t = 0 when the mean difference is equal to 0. a. True b. False

True

Which of the following is an example of citation bias? a. a researcher does not cite any references in an article b. a researcher cites the full reference of an article after skimming only the abstract of that article c. a researcher cites references for articles that both support and contradict her own viewpoint d. a researcher cites only evidence that supports her view and fails to cite conflicting evidence in her research paper

a researcher cites only evidence that supports her view and fails to cite conflicting evidence in her research paper

The aims of ethical standards in behavioral research are to: a. protect the researcher from liability for their part in a research study b. ensure that all human participants are informed and protected from harm c. ensure that only studies with absolutely no risk to participants are conducted d. make sure that ethical behavior is the sole responsibility of ethics committees

ensure that all human participants are informed and protected from harm

The mean of the sampling distribution of sample means is: a. equal to the population mean b. equal to the population variance c. both A and B d. none of the above

equal to the population mean

A key difference between a t statistic and a z statistic is that the standard error is ________ to compute a t statistic. a. removed b. replaced c. estimated d. placed in the numerator

estimated

Factors that threaten ____ validity will vary systematically with the independent variable. a. internal b. external c. both a and b

internal

The distribution of personal income for U.S. citizens is positively skewed. If the median annual income is $44,000, this implies that the mean annual income is: a. smaller b. larger c. the same d. There is not enough information to answer this question

larger

The variance and standard deviation can never be: a. zero b. negative c. smaller than the mean d. larger than the mean

negative

An education counselor records the number of high school graduates enrolling in community colleges, four-year colleges, and universities. What scale of measurement is the type of college? a. ordinal b. ratio c. interval d. nominal

nominal

The ethical conflict in research arises from researchers' desires to achieve ______ regardless of the ______ required to achieve those results. a. means; outcomes b. data; consent c. outcomes; means d. consent; data

outcomes; means

All other things being equal, the value in the numerator is computed the same for sample variance and population variance. a. True b. False

True

As sample size increases, the power to detect an effect increases. a. True b. False

True

Estimates of proportion of variance, eta-squared and omega-squared, are computed the same for all t tests. a. True b. False

True

Which of the following is an advantage for selecting related samples compared to selecting independent samples in behavioral research? a. selecting related samples can be more practical b. selecting related samples minimizes standard error c. selecting related samples increases power d. all of the above

all of the above

Which of the following is an example of an environmental factor that should be controlled for to strengthen the internal validity of a study? a. the time of day that a study is conducted b. how participants are treated by the researcher in each group c. the location in which a study is conducted d. all of the above

all of the above

In hypothesis testing, a researcher's decision: a. is based on a probability b. depends on the level of significance for a hypothesis test c. can be to retain or reject the null hypothesis d. all of the above.

all of the above.

Which of the following "3 Cs" of an effective literature review explains that you should ask questions, know your sources, and remain objective during a literature review? a. be clever b. be considerate c. be critical d. be comprehensive

be critical

________ is an ethical principle listed in the Belmont Report that states that it is the researchers responsibility to minimize the potential risks and maximize the potential benefits associated with conducting a research study. a. justice b. respect for persons c. all of the above d. beneficence

beneficence

The APA code of ethics extends the ethical principles outlined in the Belmont Report to include which additional principles? a. fidelity and responsibility, and integrity b. beneficence and justice c. respect for persons and fidelity d. justice and integrity

beneficence and justice

Which of the following is a way in which a theory can be tested? a. the predictions of a theory can be tested b. the limitations of a theory can be tested c. both a and b d. none of the above; a theory cannot be tested because it is supported by scientific observations

both a and b

Researchers establish control by: a. manipulating the levels of a variable b. holding other variables constant c. observing quasi-independent variables d. both a and b

d. both a and b

Citing an original article that was described in your paper ensures that the person with priority for the discovery is given: a. proper credit b. a monetary reward c. undue credit d. secondary credit

proper credit

State the critical value(s) for a t test using a .05 level of significance in the lower tail only: t(24). a. ±1.711 b. -1.711 c. ±2.064 d. -2.064

-1.711

What is the typical level of significance for a hypothesis test in behavioral research? a. .05 b. .10 c. 1.00 d. .95

.05

Which measure of effect size is most commonly reported with a t test? a. eta-squared b. omega-squared c. Cohen's d d. the t statistic

Cohen's d

A researcher reads an article that reports a significant result. While reading this article, the researcher identifies a hypothesis to explain the findings reported in that article. Which step of the scientific method is described in this example? a. analyze and evaluate data b. conduct the study c. communicate the results d. identify a problem

Identify a problem

A researcher reports that the size of an effect in some population is d = 0.88. Which of the following is an appropriate interpretation for d? a. The effect observed in the population was significant b. Mean scores were significant by 0.88 points in the sample c. Mean scores were significant by 0.88 points in the population d. Mean scores shifted 0.88 standard deviations in the population

Mean scores shifted 0.88 standard deviations in the population

A researcher records the following data for the time (in seconds) it takes five rats to cross an electrical grid to obtain reinforcement on the other side: 12, 9, 13, 4, and 12. Is the mean equal to the mode in this example? a. Yes b. No; the mode is larger than the mean c. No; the mean is larger than the mode d. There is not enough information to answer this question

No; the mode is larger than the mean

Two normal distributions are observed. The first distribution has a mean of 12 and a standard deviation of 2. The second distribution has a mean of 0 and a standard deviation of 2. For which distribution will the z score for the mean be larger? a. The first z distribution b. The second distribution c. None, the z score will be the same

None, the z score will be the same

Two researchers (A and B) compute a one-sample t test. For both tests, the mean difference between the sample and value stated in the null hypothesis is 5, but the standard error is smaller for Researcher A. Which test is more likely to result in a decision to reject the null hypothesis? a. Researcher A b. Researcher B c. The likelihood is the same for both researchers

Researcher A

Two researchers (A and B) compute a two-independent sample t test. For both tests, the mean difference between the two groups is 10, but the standard error is smaller for Researcher A. Which test is more likely to result in a decision to reject the null hypothesis? a. Researcher A b. Researcher B c. The likelihood is the same for both researchers

Researcher A

Two researchers (A and B) compute a two-independent sample t test. For both tests, the standard error is the same, but the mean difference between the groups is larger for Researcher A. Which test is more likely to result in a decision to reject the null hypothesis? a. Researcher A b. Researcher B c. The likelihood is the same for both researchers

Researcher A

Two researchers (A and B) compute a one-sample t test. For both tests, the standard error is the same, but the mean difference between the sample and value stated in the null hypothesis is smaller for Researcher A. Which test is more likely to result in a decision to reject the null hypothesis? a. Researcher A b. Researcher B c. The likelihood is the same for both researchers

Researcher B

A researcher measures deviant behavior in a sample of 12 children from abusive homes (Sample A). Another researcher measures the same behavior in a sample of 18 children from abusive homes (Sample B). Which sample is associated with larger degrees of freedom? a. Sample A b. Sample B c. Each sample has the same degrees of freedom

Sample B

A sampling distribution is a distribution of all sample means that could be obtained in samples of a given size from the same population. a. True b. False

True

If d = 0.28, then we conclude that mean scores in some population have shifted 0.28 standard deviations above the mean. a. True b. False

True

A preexisting variable with levels to which participants are not randomly assigned that differentiates the groups or conditions being compared in a research study, is called: a. an experimental variable b. a hypothetical variable c. a construct d. a quasi-independent variable

a quasi-independent variable

Which of the following is an example of abstracting? a. a researcher cites only evidence that supports her view and fails to cite conflicting evidence in her research paper b. a researcher cites the full reference of an article after skimming only the abstract of that article c. a researcher cites all references for articles in which she read the full-text and the abstract of those articles d. a researcher reads the full-text, but not the abstract of each article that he cites in his research paper

a researcher cites the full reference of an article after skimming only the abstract of that article

A researcher compares the amount of debt (in dollars) that undergraduate students incur to earn a four-year degree. College debt is on what scale of measurement? a. ratio b. ordinal c. interval d. nominal

a. ratio

Which of the following is a commonly used database for searching scientific articles in the behavioral sciences? a. PubMed b. PsycInfo c. PsycArticles d.all of the above

all of the above

The probability of committing a Type I error is stated by ________; the probability for committing a Type II error is stated by ________. a. beta; alpha b. alpha; beta c. a p value; a p value d. the null; the power

alpha; beta

You believe that if you don't read your textbook you will fail your research methods class because your professor said so. Which method of knowing is illustrated in this example? a. intuition b. authority c. empiricism d. rationalism

authority

A researcher measures attraction among dating college students. Which of the following is an appropriate operational definition for attraction? a. the appeal of a persons' physical appearance b.the duration of a conversation (in min) between two people c. the closeness or love felt for another person d. all of the above are appropriate

b. the duration of a conversation (in min) between two people

The test statistic for a related samples t test makes tests concerning a single sample of: a. raw scores b. difference scores c. participant scores d. original data

difference scores

Researcher A measures social class as whether a person fits into the lower class, middle class, or upper class of a society; Researcher B measures social class in terms of a persons' wealth in dollars. Researcher A measured social class as a ________ variable; Researcher B measured social class as a ________ variable. a. continuous; discrete b. discrete; continuous c. continuous; continuous d. discrete; discrete

discrete; continuous

An audience member knows that a magic trick is an illusion because he saw how the trick was done. Which method of knowing is illustrated in this example? a. tenacity b. authority c. empiricism d. rationalism

empiricism

The related samples design can ________ the power to detect an effect by making the standard error ________. a. increase; smaller b. increase; larger c. decrease; smaller d. decrease; minimal

increase; smaller

Peer-reviewed journals have a readership and your idea must appeal to those who read that journal if you are to publish your ideas. This suggestion appeals to which of the following questions regarding your research idea? a. is my idea novel? b. is my idea scientific? c. is my idea interesting? d. is my idea valid?

is my idea interesting?

One problem that arises because of the publication bias is that: a. authors often fail to cite all sources described in their paper b. the results reported in the peer-reviewed literature cannot be trusted c. it is possible that a reported effect is overstated d. editors preferential published negative results in favor of positive results

it is possible that a reported effect is overstated

The criteria for a decision regarding the value stated in a null hypothesis is set by the: a. level of significance b. p value c. probability of being correct d. both a and b

level of significance

Which of the following is an example of a discrete variable? a. number of students in class b. square footage of a classroom c. class duration in minutes d. height of a projector in feet

number of students in class

Respect for persons is an ethical principle listed in the Belmont Report that states that: a. it is the researchers responsibility to minimize the potential risks and maximize the potential benefits associated with conducting a research study b. the potential for an individual to participate in a research study is to be determined solely by the researcher c. participants in a research study must be autonomous agents capable of making informed decisions concerning whether to participate in research d. all participants should be treated fairly and equitably in terms of receiving the benefits and bearing the risks in research

participants in a research study must be autonomous agents capable of making informed decisions concerning whether to participate in research

Recording whom students study with describes ________ types of data; whereas recording the number of hours spent studying per week describes ________ types of data. a.continuous; discrete b. quantitative; qualitative c. discrete; continuous d. qualitative; quantitative

qualitative; quantitative

Researcher A measures study habits by recording the types of courses that students study for the most; Researcher B measures study habits as the time in minutes spent studying per week. Researcher A measured study habits as a ________ variable; Researcher B measured study habits as a ________ variable. a. quantitative; qualitative b. qualitative; qualitative c. quantitative; quantitative d. qualitative; quantitative

qualitative; quantitative

A change or shift in a participant's performance toward a level or score that is closer to or more typical of his or her true potential or mean ability on some measure, after previously scoring unusually high or low on the same measure, is called: a. history effect b. testing effect c. maturation d. regression toward the mean

regression toward the mean

A researcher asks participants to estimate the height (in inches) of a statue that was in a waiting area. The researcher records the following estimates: 40, 46, 30, 50, and 34. If the researcher removes the estimate of 40 (say, due to an experimenter error), then the value of the mean will: a. increase b. decrease c. remain the same d. become negative

remain the same

Researchers measure data in a ________ to learn more about individuals in the larger _______ of interest. a. sample; population b. statistic; inference c. population; sample d. inference; statistic

sample; population

________ is the acquisition of knowledge through observation, evaluation, interpretation, and theoretical explanation a. science b. empiricism c. authority d. statistics

science

The ________ refers to a set of systematic techniques used to acquire, modify and integrate knowledge concerning observable and measurable phenomena. a. hypothesis b. population c. scientific method d. operational definition

scientific method

Scores far from the mean are located in the ________ of a normal distribution. a. body b.tails c. most sensitive areas d. most uncertain areas

tails

________ is a published document that recommends three principles for the ethical conduct of research with human participants: respect for persons, beneficence, and justice. a. the Belmont Report b. the Bill of Rights c. the constitution d. the Nuremberg Code

the Belmont Report

Which document contains ten directives aimed to protect human participants from unnecessary harm? a. the constitution b. the Bill of Rights c. the Belmont Report d. the Nuremberg Code

the Nuremberg Code

Which is an appropriate operational definition for hunger? a. the duration of time (in hours) since a previous meal b. both a and b c. a physical state of energy deprivation signaled by the body

the duration of time (in hours) since a previous meal

The generalizability of outcomes in a research design directly relates to: a. the certainty of truth b. the internal validity of the study c. the external validity of the study d. the extent to which the study demonstrated cause-and-effect

the external validity of the study

The level of control in a research design directly relates to: a. the certainty of truth b. the internal validity of the study c. the external validity of the study d. the level of responsiveness in a study

the internal validity of the study

In the 1940's penicillin became widely available as an effective treatment for syphilis. What did the researchers in the Tuskegee syphilis study do in response to this new treatment? a. they conducted their own study that showed that penicillin was not an effective treatment for syphilis b. they terminated the study and had all participants treated c. they denied the men access to penicillin and continued the study d. they allowed participants to choose whether or not to seek treatment

they denied the men access to penicillin and continued the study

Which of the following statements about the nonexperimental research design is true? a. using a nonexperimental research design we can show that changes in a dependent variable are caused by an independent variable b. using a nonexperimental research design the behaviors or variables of interest are observed without an intervention or manipulation from the researcher c. using a nonexperimental research design the study is structured like an experiment, except that the conditions and experiences of participants are not under the full control of the researcher d. using a nonexperimental design we can manipulate a preexisting variable that differentiates the groups or conditions being compared in a research study

using a nonexperimental research design the behaviors or variables of interest are observed without an intervention or manipulation from the researcher

The sum of the differences of scores from their mean is: a. minimal b. zero c. negative d. negligible

zero

A researcher records the strength of a conditioned response among 12 rats in the presence and absence of conditioned cues. If she computes a related samples t test at a .05 level of significance (two-tailed test), then what are the critical values for this test? a. ±2.201 b. ±2.179 c. ±1.796 d. ±1.782

±2.201