Deck 5: Sampling and Probability

Question 1

Dr.Baker designed an experimental study to assess potential differences between science students and art students on a math reasoning abilities test.Dr.Baker found a mean difference in math performance between science and art students.On average, art students performed higher on the math reasoning test compared to the science students.Dr.Baker's results were supported in two other studies performed in university settings.Dr.Baker concluded that, given that the results of her study have been replicated at other universities, her findings were reliable.Dr.Baker also hopes that other researchers will perform the study using other samples including participants from the community.Dr.Baker is concerned about replicating her study across various settings and using additional samples because she wishes to:

A) improve the generalizability of her results.
B) support her null hypothesis.
C) improve her descriptive statistics.
D) calculate a probability.

Answer 1

improve the generalizability of her results.

Question 2

The extent to which research findings from one sample or context can be applied to other samples or contexts is called:

A) replication.
B) generalizability.
C) sampling.
D) probability.

Answer 2

generalizability.

Question 3

_____ sampling is the method most likely to lead to a representative sample.

A) Random
B) Convenience
C) Self-selected
D) Volunteer

Answer 3

Random

Question 4

External validity is _____ by the use of volunteer samples.

A) weakened
B) strengthened
C) divided in half
D) doubled

Question 5

A researcher interested in the concept of preparedness sets up a booth at a local mall.Her idea is to compare men and women in terms of what they carry on their person, and to evaluate what types of events or issues they are prepared to handle based on what they are carrying with them.She hangs a sign on her booth that reads, "Research study underway; stop here to participate." Everyone who willingly participates in her study is part of a:

A) convenience sample.
B) random sample.
C) volunteer sample.
D) random assignment.

Question 6

True _____ is difficult and sometimes impossible to attain.

A) random assignment
B) cluster sampling
C) convenience sampling
D) random sampling

Question 7

A researcher interested in the concept of preparedness sets up a booth at a local mall.Her idea is to compare men and women in terms of what they carry on their person, and to evaluate what types of events or issues they are prepared to handle based on what they are carrying with them.She has chosen a mall setting because people are readily available.In this sense, people at the mall are a:

A) convenience sample.
B) random sample.
C) selected sample.
D) random assignment.

Question 8

When one considers whether the results of a laboratory study will actually hold up as true when applied to the world outside of the laboratory, one is considering the _____ of the findings.

A) globalization
B) external validity
C) reliability
D) expected relative-frequency probability

Question 9

A _____ sample is a type of convenience sample.

A) random
B) volunteer
C) replication
D) population

Question 10

Students who post responses on ratemyprofessor.com are what type of sample?

A) cluster
B) random
C) convenience
D) volunteer

Question 11

A researcher has conducted a study on logical reasoning using a sample of college freshmen and is concerned that the results of the study may not accurately depict the logical reasoning of college seniors.The researcher's concern can be described as a concern about the _____ of the study results.

A) replication
B) accuracy
C) generalizability
D) design

Question 12

A researcher is interested in comparing reaction time differences between men and women.He obtains a sample of 45 students from a psychology student research database.Participants take part in the study, the data are later analyzed, and the researcher concludes that women have faster reaction times compared to men.What is a potential limitation of the study's conclusion?

A) generalizability
B) plagiarism
C) random sampling
D) random selection

Question 13

Successful replication of research builds a case for the generalizability of findings.In order for replications to build that strong case, it is important that they occur in:

A) similar situations with similar participants so as to encourage the same findings.
B) inconsistent contexts using different measures from the original study.
C) a new context or with samples that have different characteristics.
D) designs with experimental and control groups that used random sampling.

Question 14

A researcher is interested in comparing reaction time differences between men and women.He obtains a sample of 45 students from a psychology student research database.Participants take part in the study, the data are later analyzed, and the researcher concludes that women have faster reaction times compared to men.What type of sampling strategy was used in this study?

A) true
B) population
C) convenience
D) random

Question 15

Random sampling is the method most likely to lead to a _____ sample.

A) biased
B) convenience
C) self-selected
D) representative

Question 16

A random numbers table or online generator is often used by researchers to create random selection or assignment because:

A) use of tables and computers increases the quality of the scientific investigation.
B) they guarantee equal assignment of participants across levels of the independent variable.
C) in general, people are poor at judging randomness and therefore must use a machine to generate random sequences.
D) their use ensures less bias in the research observations.

Question 17

_____ sampling or _____ sampling is a type of convenience sampling.

A) Random; volunteer
B) Random; self-selective
C) Volunteer; self-selective
D) Volunteer; research

Question 18

Why are true random samples rarely used?

A) Researchers rarely have access to the entire population.
B) Convenience sampling is easier and just as effective in producing a sample that can be generalized to the population of interest.
C) Random sampling methods are not effective in producing a sample that can generalized to the population of interest.
D) Researchers, like most people, have misconceptions of randomness.

Question 19

A sample in which every member of the population has an equal chance of being selected for inclusion in the study is a _____ sample.

A) convenience
B) representative
C) volunteer
D) random

Question 20

As part of their work in a research methods class, a group of psychology students devised a survey to assess the relation between stress and health.Each member of the class administered the survey to 10 friends, and the data were then pooled.What method of sampling was used?

A) random
B) convenience
C) representative
D) population

Question 21

Jessica Simpson, the famous pop star who has served as a spokesman for the anti-acne skin care product Proactiv, is an example of _____.While her claims are very impressive and persuasive, a well-designed study would provide more convincing evidence in support of this acne cure.

A) random selection
B) replication
C) a testimonial
D) personal probability

Question 22

Which of these is an example of randomly assigning participants to conditions in a study?

A) Susie places the first six people to show up for her study in the experimental group and the next six people in the control group.
B) Every time a participant shows up for his study, Mark flips a coin to determine which condition to put the participant in.He predetermined that heads is the control group and tails is the experimental group.
C) Clarice has identified her population of interest as all students attending the local county high school.She then proceeds to randomly choose high school students for her study by having a random number generator generate possible high school ID numbers.
D) Devon gives his problem-solving task to a group of first graders in the classroom for which he is a student teacher.

Question 23

A duplication of scientific results in a different context or with a different sample is:

A) an illusory correlation.
B) plagiarism.
C) replication.
D) generalizability.

Question 24

The statement "There's a 75 percent chance that I will pass my history class" best illustrates which concept?

A) subjective probability
B) expected-relative frequency probability
C) hypothesis testing
D) Type I error

Question 25

The saying "a watched pot never boils" claims an association between the temperature at which water boils and spectator presence.This is an example of a(n):

A) false assumption.
B) expected relative-outcome probability.
C) confirmation bias.
D) illusory correlation.

Question 26

In a set of clinical trials, a pharmaceutical company wishes to assess the effectiveness of its newly developed drug for depression by comparing its performance to the leading drug currently on the market and to a placebo control.What research technique or techniques would be possible and appropriate?

A) random assignment but not random selection
B) random selection but not random assignment
C) both random selection and random assignment
D) neither random selection nor random assignment

Question 27

The expected outcome if an experiment is repeated many, many times is the:

A) underlying probability.
B) reliable outcome.
C) expected relative-frequency probability.
D) expected outcome.

Question 28

Confirmation bias predicts that people will be most cynical about:

A) studies containing Type I errors.
B) studies containing Type II errors.
C) research findings that they do not like.
D) research findings that they like.

Question 29

If Dr.Bui uses random assignment in her research, then she can make the reasonable assumption that:

A) her experimental and control groups have similar characteristics prior to receiving the experimental treatment.
B) any observed differences between her experimental and control groups are statistically significant.
C) her findings can be generalized to populations she has not yet studied.
D) the participants in her study are extremely similar to the people in the larger populations from which they were selected.

Question 30

A tendency to pay attention to evidence that confirms one's a priori belief is called:

A) an illusory correlation.
B) personal probability.
C) a Type I error.
D) confirmation bias.

Question 31

Marco insists that women are poorer drivers than men.To back up his claim he describes two incidents: one in which his girlfriend sideswiped a car and a second in which his mother failed to react in time to avoid hitting a squirrel on the highway.Marco's attention to this positive evidence for his belief reflects:

A) generalizability.
B) an illusory correlation.
C) a confirmation bias.
D) personal probability.

Question 32

Random selection is _____ used, but random assignment is _____ used.

A) always; rarely
B) frequently; rarely
C) rarely; frequently
D) rarely; always

Question 33

As a woman, Jenny has noticed that males always use the middle armrests on airplanes.While those armrests are shared by two seats, she never seems to get to use them if she is in a center seat between two males.Jenny can remember several cases where this has happened to her.Her selective memory for these cases is an example of:

A) representativeness.
B) confirmation bias.
C) an illusory correlation.
D) personal probability.

Question 34

A random-digit generator is MOST likely to be used for which type of strategy?

A) convenience sampling
B) volunteer sampling
C) random assignment
D) hypothesis testing

Question 35

Meredith is a nurse in the obstetrics ward of a hospital.She tells her friend that at her hospital more babies are born when there is a full moon.The hospital's records show no such relationship, however.Meredith's belief is an example of:

A) generalizability
B) an illusory correlation.
C) a Type I error.
D) a Type II error.

Question 36

Volunteer samples are:

A) preferred to random samples.
B) not preferred to random samples.
C) provide similar results to random samples.
D) allow for greater generalizability than random samples.

Question 37

When his boss asked him the likelihood that he would be able to produce the annual report by next Friday, Joshua told him that he was 90 percent likely to complete it by the deadline.Joshua's estimate is:

A) a personal probability.
B) the expected relative-frequency probability.
C) an expected outcome.
D) generalizable.

Question 38

Random assignment differs from random selection because:

A) random assignment deals with how participants for a study are chosen to begin with, whereas random selection deals with how participants in a sample are assigned to levels of the independent variable.
B) random assignment deals with how participants in a sample are assigned to levels of the independent variable, whereas random selection deals with how participants for a study are chosen to begin with.
C) random assignment is rarely achieved, but random selection is almost always achieved.
D) random assignment must be performed by the experimenter who is carrying out the study, but random selection can be carried out at the analysis stage.

Question 39

Sandra wishes to study the effects of a mother's cocaine use during pregnancy on cognitive indicators during the first month of her infant's life.What research technique or techniques would be possible and appropriate?

A) random assignment but not random selection
B) random selection but not random assignment
C) both random selection and random assignment
D) neither random selection nor random assignment

Question 40

In an in-class demonstration of a classic experiment on the effects of smiling on happiness, an instructor had students sitting on the left side of the classroom read a series of cartoons while frowning and had students sitting on the right side of the classroom read the same series of cartoons while smiling.In this example, the instructor failed to:

A) obtain a small sample size.
B) randomly assign participants to conditions of the study.
C) recruit a convenience sample.
D) calculate the subjective probability of group membership.

Question 41

In a study of the effects of humor on memory, Schmidt (1994) had participants read either humorous sentences or non-humorous sentences, and then he later tested participants' memory for the sentences.The control group in this experiment was:

A) the group of participants assigned non-humorous sentences.
B) the group of participants assigned humorous sentences.
C) a third group of participants who were not asked to read any sentences.
D) irrelevant because there was no control group in this experiment.

Question 42

Brent tosses a quarter 4 times and 3 times it comes up heads.The percentage of heads is:

A) 0.75%.
B) 7.5%.
C) 75%.
D) 50%.

Question 43

A(n) _____ refers to each time a procedure is carried out.

A) success
B) failure
C) trial
D) outcome

Question 44

What is the correct formula for calculating a probability?

A) divide number of trials by number of errors
B) divide number of successes by number of trials and multiply by one hundred
C) divide number of trials by number of errors and multiply by one hundred
D) divide number of successes by number of trials

Question 45

A(n) _____ refers to the result of a(n) _____.

A) success; failure
B) failure; trial
C) trial; outcome
D) outcome; trial

Question 46

In a standard deck of playing cards, there is a total of 52 cards, 12 of which are face cards, such as queens, kings, and jacks.What is the formula for the expected relative-frequency probability of drawing a single face card from the deck of cards?

A) 3/52
B) 12/52
C) (12 - 3)/52
D) 52/12

Question 47

When the outcome of one trial does not depend, in any way, on the outcome of previous trials, the events are said to be _____.

A) dependent
B) independent
C) confirmatory
D) confounding

Question 48

Percentage is simply the _____ multiplied by 100.

A) proportion
B) number of successes
C) number of failures
D) number of trials

Question 49

All of the recent children born into Jessica's family have been males, so there is a lot of pressure for her and her husband Matt to have the first granddaughter.In fact, everyone is sure that their first child will be a girl, because the family is due to have one! Unfortunately for their families, this logic is false because:

A) the birth of a girl occurs only under the law of large numbers.
B) the sex of their child is independent of that of any previous children born.
C) the probability of a girl is less than that of a boy being born.
D) an illusory correlation exists between gender and family expectations.

Question 50

Whereas _____ are not good at generating random numbers because of consideration of previous events, _____ have no memory for previous events and can therefore be unbiased.

A) researchers; students
B) computers; random numbers tables
C) humans; computers
D) students; researchers

Question 51

Without many trials, one cannot determine true probabilities of events.However, over the long run, and numerous trials, the expected relative-frequency probability of events is very clear and predictable.This is known as the:

A) independence of trials.
B) law of large numbers.
C) long-run probability calculation.
D) objective probability.

Question 52

A trial refers to each time a procedure is:

A) a success.
B) a failure.
C) carried out.
D) expected to succeed.

Question 53

A(n) _____ refers to the outcome for which one is trying to determine the probability.

A) success
B) failure
C) trial
D) outcome

Question 54

Janice tosses a quarter 10 times and finds that 4 of the 10 times the quarter comes up heads and 6 of the 10 times the quarter comes up tails.What should Janice conclude?

A) The quarter is an unfair quarter.
B) The expected relative frequency probability of getting heads when tossing a quarter is 4/10.
C) It is more probable to get heads than it is to get tails when tossing a quarter.
D) In the long-term the expected relative frequency would be 5/5, but with only 10 trials a different pattern has emerged.

Question 55

Brent tosses a quarter 4 times and 3 times it comes up heads.The proportion of heads is:

A) 0.75.
B) 1.00.
C) 0.50.
D) 0.25.

Question 56

_____ refers to the occurrence of events over the long run, and _____ refers to the calculation of the number of successes divided by the number of trials.

A) Proportion; percentage
B) Percentage; proportion
C) Probability; percentage
D) Probability; proportion

Question 57

Which of these are independent events?

A) chance of winning three hands of poker in a row
B) drawing two cards from a deck of cards without placing either back in the deck
C) opinions of two friends on the latest summer blockbuster
D) sexual satisfaction of spouses who are married to each other

Question 58

Two events are said to be independent events when:

A) the probability of one event is influenced by the occurrence of the other event.
B) you do not have knowledge about the occurrence of either event.
C) the probability of one event is determined by the occurrence of the other event.
D) the probability of one event is not influenced by the occurrence of the other event.

Question 59

Brent tosses a quarter 4 times and 3 times it comes up heads.The probability of heads is:

A) 0.75.
B) 1.00.
C) 0.25.
D) 0.50.

Question 60

A researcher is interested in the eventual divorce rates of people who live together before they get married compared to those who do not cohabitate before marriage.The researcher is particularly interested in the couples who cohabitate to see if that leads to higher divorce rates.In a sense, the couples who do not cohabitate are serving as the _____ group.

A) independent
B) null
C) experimental
D) control

Question 61

A statement that postulates that two populations are NOT different from one another is a(n) _____ hypothesis.

A) null
B) research
C) illusory
D) control

Question 62

Jenny hypothesized that older adults would score higher on emotional intelligence measures compared to younger adults in her study.If the results are in support of Jenny's hypothesis, she would:

A) commit Type II error.
B) reject the null hypothesis.
C) fail to reject the null hypothesis.
D) commit a Type I error.

Question 63

A(n) _____ is a level of the _____ that receives a manipulation.

A) experimental group; independent variable
B) independent variable; experimental group
C) control group; independent variable
D) independent variable; control group

Question 64

A statement that postulates that there is no difference between populations is a:

A) negative statement.
B) null hypothesis.
C) research hypothesis.
D) positive statement.

Question 65

On April 16, 2007, BBC News reported the results of a study done by Dr.David Lewis of Mindlab International in the United Kingdom.Dr.Lewis found that eating dark chocolate had longer lasting excitatory effects on the body than did kissing a romantic partner.From his statement, it is evident that Dr.Lewis:

A) rejected the null hypothesis.
B) committed a Type I error.
C) failed to reject the null hypothesis.
D) committed a Type II error.

Question 66

A researcher is interested in the eventual divorce rates of people who live together before they get married compared to those who do not cohabitate before marriage.The researcher is particularly interested in the couples who cohabitate to see if that leads to higher divorce rates.In a sense, the couples who cohabitate are serving as the _____ group.

A) independent
B) null
C) experimental
D) control

Question 67

A(n) _____ is a level of the _____ that does not receive a manipulation.

A) experimental group; independent variable
B) independent variable; experimental group
C) control group; independent variable
D) independent variable; control group

Question 68

Dr.Baker designed an experimental study to assess potential differences between science students and art students on a math reasoning abilities test.Dr.Baker found a mean difference in math performance between science and art students.On average, science students performed higher on the math reasoning test compared to the art students.Dr.Baker's findings support which hypothesis?

A) research
B) null
C) statistical
D) experimental

Question 69

A researcher is interested in the eventual divorce rates of people who live together before they get married compared to those who do not cohabitate before marriage.Any difference found between these groups would be of interest to the researcher, as well as to the popular media.Which statement is an appropriate research hypothesis for this research?

A) There is no difference in divorce rates between those who cohabitate and those who do not.
B) There is a difference in divorce rates between those who cohabitate and those who do not.
C) People who cohabitate before marriage have a divorce rate twice as high as those who do not.
D) People who do not cohabitate before marriage have a divorce rate twice as high as those who cohabitate.

Question 70

On April 16, 2007, the BBC News reported the results of a study done by Dr.David Lewis of Mindlab International in the United Kingdom.Dr.Lewis found that eating dark chocolate had longer lasting excitatory effects on the body than did kissing a romantic partner.This is the first study to show such large effects of chocolate.If this study cannot be replicated, it implies that the researchers made a _____ error.

A) Type II
B) research design
C) statistical analysis
D) Type I

Question 71

Ethan once heard that wearing colorful socks helped release your positive energy toward others.Being the scientist that he is, he decided to put the claim to the test by running a well-designed study.He had 18 people wear colorful socks and another 18 people wear white socks.After carefully designing, collecting, and analyzing his data, he found no differences between the groups that he studied.What conclusion should he make?

A) Fail to reject the null hypothesis and conclude that colorful socks do not help release your positive energy toward others.
B) Fail to reject the null hypothesis and conclude that the effect of colorful socks is not measureable.
C) Fail to reject the null hypothesis and conclude that, based on this study, he did not observe an effect for colorful socks.
D) Reject the null hypothesis and conclude that colorful socks may benefit positive energy.

Question 72

A researcher is interested in the eventual divorce rates of people who live together before they get married compared to those who do not cohabitate before marriage.Any difference found between these groups would be of interest to the researcher, as well as to the popular media.Which statement is an appropriate null hypothesis for this research?

A) There is no difference in divorce rates between those who cohabitate and those who do not.
B) There is a difference in divorce rates between those who cohabitate and those who do not.
C) People who cohabitate before marriage have a divorce rate twice as high as those who do not.
D) People who do not cohabitate before marriage have a divorce rate twice as high as those who cohabitate.

Question 73

In a study of the effects of humor on memory, Schmidt (1994) had participants read either humorous sentences or non-humorous sentences and later tested participants' memory for the sentences.Identify the research hypothesis for this study.

A) There is no difference in memory for humorous and non-humorous sentences.
B) Humorous sentences are better remembered than non-humorous sentences.
C) Participants remember, on average, 3.5 sentences.
D) Participants have poor memory for all of the sentences.

Question 74

In a study of the effects of humor on memory, Schmidt (1994) had participants read either humorous sentences or non-humorous sentences and then later tested participants' memory for the sentences.Identify the null hypothesis this study.

A) There is no difference in memory for humorous and non-humorous sentences.
B) Humorous sentences are better remembered than non-humorous sentences.
C) Participants remember, on average, 3.5 sentences.
D) Participants have poor memory for all of the sentences.

Question 75

A statement that postulates that two populations are different from one another is a(n) _____ hypothesis.

A) null
B) research
C) illusory
D) control

Question 76

If a researcher rejects the null hypothesis when the null hypothesis is in fact true, the researcher has:

A) made a Type II error.
B) made a Type I error.
C) made an illusory correlation.
D) fallen prey to the confirmation bias.

Question 77

Ethan once heard that wearing colorful socks helped release your positive energy toward others.Being the scientist that he is, he decided to put the claim to the test by running a well-designed study.He had 18 people wear colorful socks and another 18 people wear white socks.After carefully designing, collecting, and analyzing his data, he found no differences between the groups that he studied.Which of these represents failing to reject the null hypothesis, something he should NOT do?

A) Fail to reject the null hypothesis and conclude that colorful socks do not help release your positive energy toward others.
B) Fail to reject the null hypothesis and conclude that the effect of colorful socks is not measureable.
C) Fail to reject the null hypothesis and conclude that, based on this study, he did not observe an effect for colorful socks.
D) Reject the null hypothesis and conclude that colorful socks may benefit positive energy.

Question 78

A researcher's decision regarding whether to reject the null hypothesis is based on:

A) the researcher's a priori theory regarding expected group differences.
B) independent confirmation by researchers in other laboratories.
C) the probability that group differences would be observed if there was no effect of the independent variable.
D) whether the results of the study have been replicated at least once.

Question 79

In a study of the effects of humor on memory, Schmidt (1994) had participants read either humorous sentences or non-humorous sentences and then later tested participants' memory for the sentences.The experimental group in this experiment was:

A) the group of participants assigned non-humorous sentences.
B) the group of participants assigned humorous sentences.
C) a third group of participants who were not asked to read any sentences.
D) irrelevant because there was no experimental group in this experiment.

Question 80

A placebo group is an example of a type of a(n) _____ group.

A) experimental
B) research
C) control
D) dependent