Deck 15: Sampling

Question 1

A researcher studying depression in relation to five predictor variables decides to include five more variables in a study because the literature reveals that they may also be involved in depression. Consequently, the researcher should do which of the following?

A)Use a larger sample size.
B)Set beta at a lower level.
C)Perform additional reliability and validity tests.
D)Change the design of the research from correlational to descriptive.

Answer 1

Use a larger sample size.

Question 2

Which of the following types of sampling is least common in qualitative research?

A)Convenience
B)Purposive
C)Snowball
D)Random

Answer 2

Random

Question 3

Convenience sampling + stratification = what?

A)Stratified random sampling
B)Quota sampling
C)Purposive sampling
D)Cluster sampling

Answer 3

Quota sampling

Question 4

A teacher is supposed to be randomly assigning students to experimental and control groups, for participation in a learning project mandated by the school district. The teacher has an alphabetized master list of the students, numbered 1 through 30. Which is the most logical way to randomly assign the students to group?

A)Put numbers 1 to 30 in a hat, draw them out one by one, and put them into alternating groups.
B)Place the first 15 subjects from the alphabetized list in one group and the last 15 in the other group.
C)Ignore numbers, and let the students choose their groups.
D)Put numbers 1 to 30 into a hat and draw one, placing it in the experimental group. Then find a student with similar gender, attributes, and abilities, and put that one into the control group. Then go back to the hat for the next experimental subject.

Question 5

A researcher wants to maximize the generalizability of a planned experimental study's results. What can the researcher do to achieve this goal, relative to sampling?

A)Select a sample larger than that recommended by power analysis.
B)Purposively select a sample that is extremely heterogeneous.
C)Use random assignment.
D)Use random sampling.

Question 6

A pollster wants to obtain a large sample of voters with the least amount of trouble. Each subject is asked to complete a pencil-paper questionnaire containing seven multiple-choice questions. Each person completing the survey receives a $1 off coupon for a regional coffee chain. The pollster decides to stand outside 20 different supermarkets for 4 hours each and ask patrons to participate in the research. Which method of sampling is this?

A)Network or snowball sampling
B)Purposive sampling
C)Convenience sampling
D)Cluster sampling

Question 7

"To be considered eligible for the study, subjects had to be older than 21 years of age, hold a valid state driver's license, and be able to fire a shotgun." What part of the study sample description is this?

A)Inclusion plan
B)Population element
C)Sampling criteria
D)Representativeness

Question 8

A researcher studies spending habits of teenagers in shopping malls. The researcher visits two local malls to solicit participants. From what kind of population has the researcher selected the sample?

A)The accessible population
B)The entire population
C)The target population
D)The hypothetical population

Question 9

A researcher is studying sleep habits of household cats that belong to families with small children. The families live in urban areas. In this study, what is/are the element(s)?

A)Small children
B)Household cats
C)Families
D)Sleep

Question 10

A researcher consented 75 subjects, but 15 dropped out of the study while it was still in progress. What was the sample attrition rate?

A)10%
B)15%
C)20%
D)75%

Question 11

How does effect size relate to instrument sensitivity?

A)If an instrument is sensitive, it will have a large effect size.
B)If an instrument is not very sensitive, it will take a large effect size for the instrument to detect a difference.
C)As an instrument is better calibrated and becomes more sensitive, it increases in effect size.
D)If an instrument is extremely sensitive, it will detect a difference even when none exists; because of this effect sizes must be large.

Question 12

A woman answers the telephone and hears, "Good morning. You have been selected randomly by our marketing department because of your recent purchase of McCarthy's Natural Yogurt, several organic raw vegetables, and two types of tofu. As a woman with interest in safe and healthy products, we are asking you to participate in a brief telephone survey." What is this?

A)Random sampling
B)Convenience sampling
C)Purposive sampling
D)Systematic sampling

Question 13

A researcher has already written a study proposal and performed a power analysis, which indicates that the sample size will have to be at least 36, in order to avoid Type II error. The researcher then decides to set the level of significance at p < 0.01 rather than p < 0.05 but wants to maintain power at 0.80. What will the researcher have to do in order to maintain sufficient power?

A)Increase the effect size.
B)Set beta at 0.60.
C)Use a different statistical test.
D)Increase the sample size.

Question 14

A researcher selects a sample in this way. The researcher paints numbers on 100 ping-pong balls and paints half of the balls blue and half of them green. The researcher puts the blue half onto a large tray and the green half onto another large tray. Then the researcher mixes each tray of balls and trains a dog to bring 10 balls from each tray to the researcher, gently and systematically, one at a time. What type of sample is this?

A)Snowball
B)Random
C)Stratified random
D)Systematic

Question 15

A sample is chosen for a study on average heights and weights of adult males in a major city. The researcher uses a convenience sampling method, enacting this by going door-to-door in a neighborhood in St. Paul, Minnesota. Unbeknownst to the researcher, this neighborhood is very rich in persons of Norwegian descent, who coincidentally are the tallest Caucasians on the planet. What type of sampling error is most likely to occur due to this sampling method?

A)Random variance
B)Refusal rate
C)Systematic bias
D)Type II error

Question 16

A researcher contacts seven large hospitals and makes arrangements to recruit 55 patients from each of their emergency rooms. If this is cluster sampling, how were the seven large hospitals chosen?

A)By size
B)By random selection
C)By availability
D)By researcher familiarity

Question 17

Five hundred persons were chosen to participate in a study, 270 women and 230 men, representative of the proportion of adult women and men in the population of Portland, Oregon. Patients were selected using a table of random numbers, from a master list of all patients who had been treated for congestive heart failure (CHF) in the previous 3 months at one of Portland's four main hospitals. This is an example of what type of sampling strategy?

A)Simple random sampling
B)Convenience sampling
C)Purposive sampling
D)Stratified random sampling

Question 18

A research study examined the partying styles of students in fraternities, in sororities, living in dorms, and living in private residences. Ten students from each group were included in the research. This is an example of which type of sampling strategy?

A)Quota sampling
B)Cluster sampling
C)Purposive sampling
D)Stratified random sampling

Question 19

Choose the nonprobability sampling method.

A)Cluster
B)Quota
C)Stratified random
D)Systematic

Question 20

A graduate student has a close friend who is recovering from colon cancer and has a permanent colostomy. For the master's thesis, the student decides to conduct qualitative research on adjustment to living with a permanent colostomy after colon cancer resection. The student asks the friend for help in recruiting participants for the research. The friend identifies a colon cancer support group to which the friend belongs and volunteers to bring a printout of the research study's purpose and general description to the next support group meeting. If the researcher acquires all of the study participants in this way, what is the method of sampling used?

A)Snowball sampling
B)Cluster sampling
C)Purposive sampling
D)Simple random sampling

Question 21

Why are broad sampling criteria preferable for descriptive nursing studies?

A)The accessible population is often limited in size.
B)They include the sample that is the most representative of the population at that site.
C)Broad sampling criteria are preferable for studies conducted in natural settings.
D)Broad sampling criteria eliminate more extraneous variables than do narrow sampling criteria.
E)Generalization is improved with broad sampling criteria.

Question 22

If the population is E, and assuming the researcher selects part of the population as a sample, what could be the sample?

A)A
B)B
C)C
D)D
E)E

Question 23

What are the true statements about inclusion and exclusion criteria?

A)Inclusion and exclusion criteria determine the demographics of the sample.
B)Inclusion and exclusion criteria are the opposites of one another.
C)Inclusion and exclusion criteria must be mutually exhaustive.
D)Inclusion and exclusion criteria must be mutually exclusive.
E)Inclusion and exclusion criteria must address the study purpose.

Question 24

What would represent a hypothetical population?

A)The average population of New Jersey
B)Babies born in taxicabs in New York City in the coming year
C)The 45 subjects whose performance supported the study hypothesis
D)The percentage of the subjects who score higher than 81 on the Test of Motor Capability
E)All of the high school students at Bountiful High School who earn their Eagle Scout rank in the academic year 2018-2019

Question 25

Large sample sizes are desirable in which types of research?

A)Correlational, using an existent database
B)Grounded theory
C)Phenomenology
D)Pilot interventional research
E)Multisite randomized clinical trials
F)Survey research
G)Model testing
H)Case study research

Question 26

A researcher consented 400 subjects, but 12 dropped out of the study before it was completed. The rest finished the study. What was the sample retention rate?

A)30%
B)38.8%
C)3%
D)97%

Question 27

Performing a power analysis allows the researcher to calculate the size needed to achieve an adequate sample. Why is it preferable to calculate this number in the design phase of a quantitative study?

A)Knowing the sample size allows the researcher to strategize how to best obtain adequate participation in the study.
B)Performing a power analysis increases the research's potential for publication.
C)Conducting a power analysis decreases the chance of Type I error.
D)Conducting a power analysis increases effect size.
E)The institutional review paperwork must include a maximum sample size.

Question 28

Why is a large refusal rate a barrier to widespread generalization?

A)If a study has a refusal rate higher than 30%, it is no longer considered research.b.If researchers cannot recruit subjects into their research studies, their credibility and ethics are under serious scrutiny.
C)The actual sample is not representative of the population. It is representative only of the elements of the population that chose to participate.
D)If many persons refuse to participate, they might refuse to participate in interventions that the study recommends.

Question 29

A hospital-based nurse researcher at Hospital A conducts experimental research on a rotating bed and its effect on prevention of pressure ulcers in hip fracture patients over 80 years of age with cognitive functional impairment. Because there are so few patients over 80 with fractured hips and cognitive functional impairment, and because the researcher anticipates problems with obtaining consent, a convenience sample is utilized and every patient who meets the criteria and consents is used in the study. The bed, although expensive, is found to be much more effective in preventing pressure ulcers in this population than is turning alone. The study is published. What are the implications of applying these findings, considering the researcher's use of a convenience sample?

A)The findings can be applied to similar patients who come to Hospital A, with the understanding that data collection will continue and represent a second study, since the research is not yet replicated.
B)The findings may be applicable to similar patients who come to Hospital B, but without replication, this use cannot be mandated in the research report.
C)The rotating bed should not be used outside of Hospital A at all until a replication study is conducted.
D)The study findings probably represent a Type I error. It is doubtful that use of a rotating bed could produce significant findings with a convenience sample.
E)The widespread use of the rotating bed has not been supported.
F)Generalization is appropriate only extremely cautiously and in the same site in which the study was conducted, with tracking of subsequent data.

Question 30

When grounded theory researchers recruit subjects who can provide relevant information to explain a cluster of interlocking ideas that is unclear to the researchers, what kind of sampling is used?

A)Theoretical sampling
B)Convenience sampling
C)Quota sampling
D)Network

Question 31

The population parameter for firefighters on Long Island is 79% male. The sample statistic for three fire stations is 73% male. Why wasn't the sample statistic the same as the population parameter?

A)Sampling error was present.
B)Random variation might have occurred.
C)Systematic variation might have occurred.
D)The sample was fairly small.
E)The sample was not perfectly representative.
F)The population parameter is inaccurate.

Question 32

If researchers are attempting to recruit subjects who are members of a group that is not mainstream and may be disdained, why is snowball sampling often used?

A)It is less time-consuming than other methods for hard-to-access populations.
B)It produces a sample that is more representative.
C)It increases recruitment success.
D)It produces a more diverse sample.
E)It increases generalizability.

Question 33

Using a table of random numbers, a sample of 400 subjects was selected from the list of the license numbers of all registered nurses in the state of Michigan. Each nurse was sent a letter requesting completion of an online survey on workplace bullying. This is an example of what type of sampling method?

A)Simple random sampling
B)Quota sampling
C)Convenience sampling
D)Purposive sampling

Question 34

If all of the tickets purchased in this week's state lottery is considered the population, the five winning tickets drawn on Saturday constitute the sample. If the lottery is not "fixed," why is this a probability sample?

A)Because according to the laws of probability, the group of five people who won is exactly representative of all of the persons who purchased tickets.
B)Because each ticket purchased has a chance of being included in the sample.
C)Because the tickets drawn have a high probability of being representative of all tickets purchased.
D)Because use of random sampling increases the probability that those persons whose tickets win will play the lottery again.
E)Because each ticket probably has an equal chance of being included in the winning group, whether or not random sampling is used.

Question 35

A researcher attempted to recruit all 150 of the patients seen in the emergency department in a 3-month period for diverticulitis, but only 120 consented to participate. What is the sample size?

A)150
B)120
C)30
D)80%

Question 36

Why are convenience samples used so frequently in nursing research?

A)More subjects consent if they can understand the sampling method.
B)Obtaining a true random sample of sufficient size may be impossible.
C)There is low risk of sampling bias.
D)There are limited subjects available.
E)Nonrandom sampling affects only generalizability, not study integrity.

Question 37

Choose the sampling design that is an example of a probability sampling method.

A)Purposive
B)Snowball
C)Stratified random
D)Quota

Question 38

Why would a researcher use an elimination criterion like "Must not have baseline liver function tests that are outside the normal range"?

A)Impaired liver function may have been identified by the researcher as an extraneous variable.
B)The intervention planned by the researcher could have an adverse effect on individuals with impaired liver function.
C)Liver function tests are possibly being measured in order to detect the independent variable's effect on the dependent variable.
D)The researcher is attempting to eliminate persons with all laboratory tests that are outside normal range.
E)The dependent variable may be abnormally elevated in persons who do not have normal liver function.

Question 39

A researcher attempted to recruit all 150 of the patients seen in the emergency department in a 3-month period for diverticulitis, but only 120 consented to participate. What is the refusal rate?

A)100%
B)80%
C)20%
D)0%

Question 40

A researcher e-mails links to an online survey about multi-tasking and overcommittedness both on and off the job, as they relate to quality of life, to a random selection of 20,000 RNs in all 50 states; this represents about 1% of the population of RNs. The return rate on the tool is 5%. The goal of this sampling method is to obtain a representative sample. Choose the correct statement(s) relative to the sample's representativeness.

A)Since the topic has to do with multi-tasking and overcommittedness, it is likely that the results will be skewed, since RNs who are vastly overcommitted will not complete the survey.
B)The sample is automatically representative if randomly selected names were used for the survey e-mailing.c.If the e-mailed subset of the population was randomly selected and the return meets the number required by power analysis, the return is representative.
D)Subjects whose perceived quality of life is either very high or very low may be more inclined to participate, since they have an interest in finding more out about this relationship.
E)If the 1000 subjects who return the survey constitute an insufficient number to demonstrate statistical significance, this means that the sample was not truly representative.
F)The sample is so huge, it would certainly be representative of the entire population.

Question 41

Why are convenience samples used so frequently in nursing research, when a random sample would allow for greater generalizability?

A)Convenience sampling allows researchers to select not only subsets but qualities associated with them.
B)Key informants are desired.
C)Random sampling is really not an issue, since little nursing research is replicated.
D)Potential subjects often are reluctant to consent for in-hospital research.
E)Nurses are limited to the populations they serve; many populations are small and difficult to access.

Question 42

Inclusion criteria differ from sample characteristics. Which of the following are plausible inclusion sampling criteria for a study conducted on an acute care ward of a major hospital?

A)Mean age 62, with range from 37 through 87
B)Twenty-four male, 12 female
C)Glasgow Coma Scale of at least 14
D)Twenty-one post-hip replacement, 15 post-knee replacement
E)Able to read and write English

Question 43

A study has a power level of 0.75. What does that mean?

A)Study interventions will be statistically significant 75% of the time.
B)The study has a 75% chance of detecting differences if they exist.
C)The study's sample has a 25% attrition rate, at worst.
D)There is a 25% chance of detecting a Type I error.
E)There is a 25% chance that the study will fail to reveal differences that actually exist.

Question 44

The researcher conducts a qualitative study that explores the feelings of nurses who care for victims of intentional burning. What sampling methods are most appropriate for this study?

A)Quota sampling
B)Purposive sampling
C)Cluster sampling
D)Stratified random sampling
E)Systematic sampling
F)Snowball sampling
G)Theoretical sampling

Question 45

Inclusion sampling criteria differ from sample characteristics. Which of the following are sample characteristics from a study conducted in a neurosurgical critical care unit of a major hospital?

A)Mean age 62, with range from 37 through 87
B)Diagnosed with neurologic impairment due to trauma or disease
C)Glasgow Coma Scale range 4 to 15
D)Twenty-one male, 19 female
E)Able to speak English or Spanish

Question 46

Why is subject selection in survey research considered nonrandom?

A)If monetary reward is offered as an inducement, subjects may participate only to get the reward. The sample may include fewer people who are well-off financially.
B)There is no direct contact with the subjects.
C)Follow-up reminders make recruitment long and drawn-out.
D)Inducements are essentially manipulative; potential subjects who resent manipulation refuse to return surveys.
E)Refusal rates average 50% or more, and this makes the sample nonrepresentative.

Question 47

Which of the following are true statements related to determination of minimum sample size?

A)In inferential quantitative research, power analysis drives sample size.
B)In pilot research, ability to address the purpose for the pilot drives sample size.
C)In descriptive research, availability of subjects drives sample size.
D)In both quantitative and qualitative research, available funding drives sample size.
E)In qualitative research, theoretical saturation drives sample size.