Chapter 10

Which of the following statements describes a population? A) All traumatic brain injury clients hospitalized in an intensive care unit during January 2012 B) Four hundred nurses selected from a membership list of American Nurses' Association (ANA) members C) Selected members of families of clients undergoing surgery D) A sample of clients diagnosed with COPD and who currently smoke

Ans: A Feedback: All traumatic brain injury clients hospitalized in an intensive care unit during January 2012 denotes a population. A population is the entire group of interest. The other answers denote only samples or segments of a population.

The sampling design that would be especially likely to yield a representative sample is which of the following? A) Consecutive B) Convenience C) Purposive D) Quota

Ans: A Feedback: Consecutive sampling involves taking all of the people from an accessible population who meet the eligibility criteria over a specific time interval, or for a specified sample size. Convenience sampling uses the most readily available or convenient group of people. In purposive sampling, participants are hand-picked to be included in the sample based on the researcher's knowledge about the population. Quota sampling divides the population into homogeneous strata (subpopulations) to ensure representation of the subgroups in the sample; within each stratum, people are sampled by convenience.

Which of the following is the most widely used data collection method by nurse researchers? A) Records B) Self-reports C) Observation D) Biophysiologic measures

Ans: B Feedback: Data collection methods vary in terms of structure, quantifiability, and objectivity. The three principal data collection methods for nurse researchers are self-report, observations, and biophysiologic measures. Self-reports, which involve directly questioning study participants, are the most widely used method of collecting data for nursing studies.

If a target population contains 10,600 elements and the researcher seeks a systematic random sample of 50, the sampling interval would be which of the following? A) 116 B) 600 C) 212 D) 53

Ans: C Feedback: To obtain the sampling interval, the size of the population is divided by the size of the desired sample.

When is a small sample size appropriate for a research study? A) Many uncontrolled variables are present. B) The population is very homogenous. C) Large differences are expected in members of the population on the variable of interest. D) The population must be divided into subgroups.

Ans: C Feedback: When expected differences are large, a large sample is not needed to reveal group differences statistically; but when small differences are predicted, large samples are necessary. In general, however, a larger sample size leads to less bias and greater reliability.

The nurse researcher is conducting a study on a nonpharmacologic nursing intervention for the treatment of pain. Which data collection instrument would provide the most sensitive measurement of pain? A) Differential scale B) Physiologic measures C) Likert scale D) Visual analog scale

Ans: D Feedback: A visual analog scale would provide the most sensitive measurement of pain, because it measures subjective experiences. Physiologic measures and the Likert scale do not effectively measure subjective experiences such as pain. There is no ìdifferential scale.î

A person who marked ìstrongly agreeî to all or most items on a Likert scale would best be described as which of the following? A) Socially desirable respondent B) Biased participant C) Nay-sayer D) Yea-sayer

Ans: D Feedback: Acquiescence response set bias is a tendency to agree with statements regardless of their content; such responders are known as ìyea-sayers.î People who have the opposite tendencyóto disagree with statements independently of the question contentóare known as nay-sayers and are much less common. Social desirability response set bias is a tendency to misrepresent attitudes or traits by giving answers that are consistent with prevailing social views. A yea-sayer is a type of biased participant.

Which group represents a convenience sample? A) The patients with a diagnosis of URI seen in the clinic on one afternoon in February B) One hundred male BSN nurses recruited by the original study subjects who are currently in leadership roles C) Middle-class Caucasian females chosen as representatives of the accessible population D) Twenty male subjects and twenty female subjects chosen for a study on gender differences

Ans: A Feedback: Convenience sampling entails selecting the most conveniently available people as participants. A nurse who distributes questionnaires about vitamin use to 100 elders at a senior citizens center is sampling by convenience, for example. The problem with convenience sampling is that people who are readily available might be atypical of the population, and so the price of convenience is the risk of bias. Convenience sampling is the weakest form of sampling, but it is also the most commonly used sampling method in many disciplines. In this case, the best example of a convenience sample is ìthe patients with a diagnosis of URI seen in the clinic on one afternoon in February,î because the sample includes only those patients who happen to be at the clinic during a short time period. The other answers indicate other sampling designs, including quota and purposive sampling.

Which of the following types of sample is considered to be the weakest for quantitative studies? A) Convenience B) Quota C) Purposive D) Systematic

Ans: A Feedback: Convenience sampling uses the most readily available or convenient group of people. The problem with convenience sampling is that people who are readily available might be atypical of the population, and so the price of convenience is the risk of bias. Convenience sampling is the weakest form of sampling, but it is also the most commonly used sampling method in many disciplines. In purposive sampling, participants are hand-picked to be included in the sample based on the researcher's knowledge about the population. Quota sampling divides the population into homogeneous strata (subpopulations) to ensure representation of the subgroups in the sample; within each stratum, people are sampled by convenience. Systematic sampling is the selection of every kth case from a list.

Questionnaires have the advantage of which of the following? A) Offering the possibility of anonymity B) Having high response rates C) Reducing the possibility of response set biases D) Being suitable for all types of study participants

Ans: A Feedback: Questionnaires are less costly than interviews and offer the possibility of anonymity, but interviews yield higher response rates (which reduce the risk for bias), are suitable for a wider variety of people, and provide richer data than questionnaires. Interviews are usually preferable to questionnaires because the quality of the data tends to be higher. Researchers using structured self-reports must decide whether to use interviews or self-administered questionnaires.

When an observer is not concealed, the findings may be biased because of which of the following? A) Reactivity B) Ethical problems C) Lack of mobility D) Acquiescence response set bias

Ans: A Feedback: Researchers do not always tell people they are being observed, because awareness of being observed may cause people to behave atypically. A behavioral distortion due to the known presence of an observer is called reactivity. It is not an ethical problem or lack of mobility. Acquiescence response set bias is a tendency to agree with statements regardless of their content by some people (yea-sayers). The opposite tendencyóto disagree with statements independently of the question contentóis less common.

Which of the following results from a sample size that is too small? A) Low power to detect a difference in the outcomes of the two groups B) Lack of control over extraneous variables C) Limits to random sampling D) A weak questionnaire survey tool

Ans: A Feedback: Sampling involves selecting a portion of the population to represent the population. A low power to detect a difference in the outcomes of the two group results from a sample size that is too small. The other answers are not effects of having a sample size that is too small.

The social desirability response set bias is least likely to be a problem on scales incorporated into which of the following? A) Mailed anonymous questionnaires B) Face-to-face interviews C) Telephone interviews D) All options are equally susceptible

Ans: A Feedback: Social desirability response set biasóa tendency to misrepresent attitudes or traits by giving answers that are consistent with prevailing social viewsówould be least likely to be a problem with mailed anonymous questionnaires, as the anonymity would likely cause people to be less concerned about what others thought of their answers.

Which of the following are advantages of using biophysiologic measures in nursing studies? Select all that apply. A) They are relatively accurate and precise B) They effectively measure subjective experiences such as pain and fatigue C) They are objective, requiring minimal inference D) They are typically cost effective because they are available for clinical purposes

Ans: A, C, D Feedback: Nurse researchers have used biophysiologic measures for a wide variety of purposes, and these measures have many advantages. They are relatively accurate and precise, objective, not easily distorted by patients, and valid. However, they cannot effectively measure subjective experiences such as pain and fatigue; a visual analog scale would be more appropriate for that.

A survey question asks subjects to respond to the following statement: "The overall hospital experience that I received during my hospital stay considered my needs as an individual."They were asked to identify, on a five-point scale, the degree to which they agreed or disagreed with the statement. This is an example of which scale? A) Social scale B) Likert scale C) Visual analog scale D) Differential scale

Ans: B Feedback: A Likert scale consists of several declarative statements (items) that express a viewpoint on a topic. Respondents are asked to indicate how much they agree or disagree with the statement. This is an example of a Likert scale. Visual analog scales measure subjective experiences. There are no ìsocialî or ìdifferentialî scales mentioned in this chapter.

Which of the following are advantages to biophysiologic measures? A) Biophysiologic measurements are subjective and accurate. B) Patients cannot distort the measurements and have objective measures. C) Biophysiologic measurements are self-reported. D) Biophysiologic measurements effectively indicate pain levels.

Ans: B Feedback: An advantage of biophysiologic measures is that patients cannot distort the measurements and they include objective measures. Biophysiologic measures include both in vivo and in vitro measures. Biophysiologic measures are accurate, precise, and objective. They are not self-reported and cannot effectively indicate pain levels.

A major advantage of closed-ended questions is that they do which of the following? A) Are easy to construct B) Are analyzed in a straightforward manner C) Encourage in-depth responses D) Are not subject to response biases

Ans: B Feedback: Good closed-ended questions are more difficult to construct than open-ended ones but easier to analyze. Closed-ended questions are also more efficient: people can complete more closed-ended questions than open-ended ones in a given amount of time. People may be unwilling to compose lengthy written responses to open-ended questions in questionnaires. A major drawback of closed-ended questions is that researchers might omit some potentially important responses. Closed-ended questions also can be superficial. Open-ended questions allow for richer information if the respondents are verbally expressive and cooperative. Finally, some respondents object to choosing from alternatives that do not reflect their opinions precisely.

Which sampling method would be most practical and provide the most reliable data to study the medication errors by registered nurses who work in city, county, and federal prisons? A) Purposive sampling B) Stratified random sampling C) Quota sampling D) Simple random sampling

Ans: B Feedback: In stratified random sampling, the population is first divided into two or more strata, from which elements are randomly selected. The aim of stratified sampling is to enhance representativeness; as a type of probability sampling, it is more reliable than nonprobability sampling. This case would be ideal for stratified random sampling, as the population is readily divided into the strata of city, county, and federal prisons. Purposive sampling is based on the belief that researchers' knowledge about the population can be used to hand-pick sample members. Quota sampling occurs when researchers identify population strata and figure out how many people are needed from each stratum. Simple random sampling is the most basic probability sampling.

Sampling may be defined as which of the following? A) Selection of an accessible population for a study B) Selection of a subset of a population to represent the entire population C) Assignment of study participants to treatment groups D) Technique for ensuring that every element in the population has an equal chance of being included in the study

Ans: B Feedback: Sampling is the process of selecting elements from a population, which is an entire aggregate of cases. An element is the basic unit of a populationóusually humans in nursing research. Eligibility criteria (including both inclusion criteria and exclusion criteria) are used to define population characteristics. Researchers usually sample from an accessible population; a broader target population is the group to which they would like to generalize their results. A key criterion in assessing a sample in a quantitative study is its represent ativeness-the extent to which the sample is similar to the population and avoids bias.

Which of the following is a probability sampling method? A) Convenience sampling B) Systematic sampling C) Consecutive sampling D) Quota sampling

Ans: B Feedback: Systematic sampling is the selection of every kth case from a list and is an example of a probability sampling method. Convenience sampling uses the most readily available or convenient group of people. Quota sampling divides the population into homogeneous strata (subpopulations) to ensure representation of the subgroups in the sample; within each stratum, people are sampled by convenience. Consecutive sampling involves taking all of the people from an accessible population who meet the eligibility criteria over a specific time interval, or for a specified sample size.

A self-report method used to measure subjective experiences such as pain and fatigue is which of the following? A) Observation B) In vivo measurements C) Visual analog scales D) Likert scales

Ans: C Feedback: A visual analog scale (VAS) is used to measure subjective experiences (e.g., pain, fatigue) along a 100 mm line designating a bipolar continuum. Observational methods are techniques for acquiring data through the direct observation of phenomena. Data may also be derived from biophysiologic measures, which include in vivo measurements (those performed within or on living organisms) and in vitro measurements (those performed outside the organism's body, such as blood tests). Biophysiologic measures have the advantage of being objective, accurate, and precise. Likert scales (or summated rating scales) present respondents with a series of items worded favorably or unfavorably toward a phenomenon; responses indicating level of agreement or disagreement with each statement are scored and summed into a composite score.

A researcher used a systematic sampling plan. The sample size was 200. The sampling interval was 250. The first element drawn was 196. The second element would be: A) 396 B) 45 C) 446 D) 646

Ans: C Feedback: By dividing the population size by the desired sample size, the researcher establishes the sampling interval, which is the standard distance between the selected elements: 196 (first element) + 250 (sample interval) = 446 (second element). 396, 450, and 646 are incorrect responses.

Interviews are usually preferable to questionnaires because of which of the following? A) They are less expensive B) They yield data that are easier to analyze C) The quality of the data tends to be higher D) They require less training of research personnel

Ans: C Feedback: Interviews are usually preferable to questionnaires because the quality of the data tends to be higher. Researchers using structured self-reports must decide whether to use interviews or self-administered questionnaires. Questionnaires are less costly than interviews and offer the possibility of anonymity, but interviews yield higher response rates, are suitable for a wider variety of people, and provide richer data than questionnaires.

On a 20-item Likert scale with five response categories, the range of possible scores is which of the following? A) 0 to 100 B) 20 to 80 C) 20 to 100 D) 0 to 50

Ans: C Feedback: Likert scales (or summated rating scales) present respondents with a series of items worded favorably or unfavorably toward a phenomenon; responses indicating level of agreement or disagreement with each statement are scored and summed into a composite score. 20 items x a score of 1 per item is 20 as the minimum score and 20 items x a score of 5 per item are 100 as the maximum score.

Strata are incorporated into the design of which of the following sampling approaches? A) Systematic B) Purposive C) Quota D) Consecutive

Ans: C Feedback: Quota sampling divides the population into homogeneous strata (subpopulations) to ensure representation of the subgroups in the sample; within each stratum, people are sampled by convenience. Consecutive sampling involves taking all of the people from an accessible population who meet the eligibility criteria over a specific time interval, or for a specified sample size. In purposive sampling, participants are hand-picked to be included in the sample based on the researcher's knowledge about the population. Systematic sampling is the selection of every kth case from a list.

Which procedure describes a probability sampling method? A) Identification of community organizations and churches in an urban setting and recruiting participants B) Identification of individuals demonstrating the variable(s) of interest to the researcher and recruiting participants C) Identification of the accessible population and selecting study participants based upon the researcher's belief that the participant is representative of the accessible population D) Identification of a sampling frame for an accessible population, writing element names on paper, placing the written names in a bowl, and drawing a select number of names from the bowl

Ans: D Feedback: Identification of a sampling frame for an accessible population, writing element names on paper, placing the written names in a bowl, and drawing a select number of names from the bowl describes a probability sampling method. This is because probability sampling involves random selection of elements from a population, which is achieved in this case by drawing names from a bowl. The other answers do not include random selection.

On a five-point Likert scale, a person who strongly agreed with a statement would be scored as which of the following? A) 1 B) 3 C) 5 D) Cannot be determined

Ans: D Feedback: Likert scales (or summated rating scales) present respondents with a series of items worded favorably or unfavorably toward a phenomenon; responses indicating level of agreement or disagreement with each statement are scored and summed into a composite score. The term needs to be indicated for each number in order to determine which number represents strongly agree or disagree.

Which of the following is an advantage of observation as a method of data collection in a study? A) Subjects may be anxious because they are being observed. B) Respondents can remain anonymous. C) It is less time consuming than a questionnaire. D) It directly captures an event and behaviors.

Ans: D Feedback: Observation directly captures an event and behaviors. Observational methods can be used to gather such information as the conditions of individuals, verbal communication, nonverbal communication, activities, and environmental conditions. Subject anxiety is not an advantage but a disadvantage of observation and may be eliminated by concealment. Respondents are not anonymous when observed, and observation is not less time consuming than a questionnaire.

Bias in a sample for a quantitative study refers to which of the following? A) Lack of heterogeneity in the population on the attribute of interest B) Sample selection using nonprobability-type sampling methods C) The margin of error in the data obtained from samples D) Systematic over- or underrepresentation of a key attribute vis-a-vis the population

Ans: D Feedback: Sampling bias is the systematic overrepresentation or underrepresentation of some segment of the population. Nonprobability sampling (in which elements are selected by nonrandom methods) includes convenience, quota, consecutive, and purposive sampling. A key criterion in assessing a sample in a quantitative study is its representativenessóthe extent to which the sample is similar to the population and avoids bias.

Which statement regarding sampling error and sampling bias is accurate? A) Sampling bias may be defined as the difference between data obtained from a simple random sample and the data that would be obtained if an entire population were measured. B) Sampling bias occurs by chance. C) Sampling error and sampling bias are synonymous. D) Sampling error may be contained in sample data even when the most careful random sampling procedure has been used to obtain the sample.

Ans: D Feedback: Sampling error may be contained in sample data even when the most careful random sampling procedure has been used to obtain the sample. There is no guarantee of a representative sample, but random selection does guarantee that differences between the sample and the population (sampling error) are purely a function of chance rather than of sampling bias. Sampling bias does not occur by chance and is not synonymous with sampling error. Sampling error, not sampling bias, is defined as the difference between data obtained from a simple random sample and the data that would be obtained if an entire population were measured.