Module 9

Which of the following refers to the technique the researchers use to estimate the minimum sample they need for their study? A. Screening B. Stratification C. Weighting D. Power analysis

D. Power analysis Feedback:In quantitative studies, researchers often use a power analysis to estimate sample size needs, which is a strategy for avoiding problems with statistical conclusion validity. The other terms are not relevant to sample size estimation.

In Johnston et. al. (2018) study, what was the specific sampling approach used (convenience sampling, quota sampling, simple random sampling, stratified random sampling)? A. Stratified random sampling B. Simple random sampling C. Probability sampling D. Since the sampling approach used wasn't specified, we could assume that convenience sampling was used.

D. Since the sampling approach used wasn't specified, we could assume that convenience sampling was used.

A researcher is studying nurses' attitudes toward evidence-based practice. The researcher created three sampling frames one for nurses with years of experience of ten years or more, a second sampling frame for nurses with five to less than ten years of experience and a third sampling frame for nurses who have less than 5 years of experience. The researcher used a random number generator to select 50 participants from each sampling frame. What type of sampling did the researcher use? A. Systematic sampling B. Simple random sampling C. Cluster sampling D. Stratified random sampling

D. Stratified random sampling

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

A. Convenience

The findings of Johnston et. al. (2018) study are generalizable to----- A. Infants and toddlers in the pediatric ICU B. All infants and toddlers C. All pediatric patients D. All PICU patients

A. Infants and toddlers in the pediatric ICU

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

A. Low power to detect difference in outcomes of the two groups.

In Johnston et. al. (2018) study, which of the following characteristics of the child sample were provided by the authors? (Select all that apply.) A. Mean PRISM score B. Mean age C. Gender D. Diagnostic category E. Types of medications administered

A. Mean PRISM score B. Mean age D. Diagnostic category

In Johnston et. al. (2018) study, what were the sample's exclusion criteria? (Select all that apply.) A. Not expected to survive B. Child's parents able to speak English or French C. Receiving paralytic agents D. Aged birth through 3 years E. Currently in children's protective services

A. Not expected to survive C. Receiving paralytic agents E. Currently in children's protective services

In Johnston et. al. (2018) study, who was the study population? A. All infants and toddlers B. All pediatric patients C. PICU patients D. Infants and toddlers in the PICU

D. Infants and toddlers in the PICU

Strengths of the Johnston et. al. (2018) study, sampling plan includes (Select All That Apply) A. The sample size was estimated based on power analysis B. The sample size sufficiently large to support statistical conclusion validity C. The researchers used a convenience sample to select the study participants D. The researchers used probability sampling in selecting the study participants E. Random assignment was used F. The sampling approach used is one that enhances the external validity of the study

A. The sample size was estimated based on power analysis B. The sample size sufficiently large to support statistical conclusion validity Feedback: Random assignment: Refers to assigning subjects at random to an experimental group or a control group. Is a signature of an experimental design (RCT). If subjects are not randomly assigned to intervention groups, then the design is not a true experiment. Random sampling: Refers to a method of selecting people for a study Random sampling is not a signature of an experimental design. Most RCTs do not involve random sampling.

Which of the following statements about sampling is correct? A. There is less risk of sampling bias with homogeneous populations than with heterogeneous populations B. The most basic units of a population are referred to as strata C. Strata is a means of equating the accessible population with the target population D. Samples that are not representative jeopardize the study's statistical conclusion validity

A. There is less risk of sampling bias with homogeneous populations than with heterogeneous populations Feedback:When a population is homogeneous with regard to characteristics that are important to the study question, there is a lower risk that the sample will be biased—that is, that it will not adequately represent the population. The most basic unit of a population is called an element, not a stratum. Strata have no role in equating accessible and target populations. Samples that are biased jeopardize external and construct validity but not statistical conclusion validity.

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

B) Selection of a subset of a population to represent the entire population

Which of the following is the definition of sampling in research studies? A. Identifying a set of criteria for selecting study participants B. Selecting a subset of the population to represent the entire population C. Determining who could participate in a study D. Ensuring that every element in the population has an equal chance of being included in the study

B. Selecting a subset of the population to represent the entire population Feedback: Sampling is the process of selecting a portion of an entire population. Eligibility criteria are used to define population characteristics and to identify people who could participate in a study. Some sampling strategies ensure that every element in the population has a chance to be sampled, but most strategies used by nurse researchers do not.

A nurse researcher is studying emergency room visits by parents of infants who were born preterm. After preparing a sampling frame, the researcher used a random number generator to select the study participants. What type of sampling did the researcher use? A. Stratified random sampling B. Simple random sampling C. Nonprobability sampling D. Convenience sampling

B. Simple random sampling Feedback:In this example, the researcher consecutively recruited every person who met the study eligibility criteria over a 12-month period. This is not an example of quota, convenience, or snowball sampling.

Which method of probability sampling is most likely to yield a representative sample? A. Convenience sampling B. Stratified random sampling C. Simple random sampling D. Random assignment

B. Stratified random sampling Feedback:Consecutive samples are least likely to result in biased samples because all eligible people over a certain period are invited to participate. Quota sampling is an improvement over convenience sampling in terms of yielding a representative sample, but sampling bias still remains a potential problem. Purposive sampling is seldom representative of the population because subjective judgment is used to select participants.

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

B. Systemic sampling

Which of the following is considered the key criterion for evaluating sample quality in quantitative research studies? A. How ethically sound is the recruitment strategy is B. How suitable the sample is to key stakeholders C. How representativeness it is of the population D. How easy it is to recruit sample members

C. How representativeness it is of the population Feedback:A key consideration in assessing the quality of a sample in a quantitative study is its representativeness of the population; another is the size of the sample. Ease of recruitment, suitability, and ethical appropriateness are relevant factors in a sampling strategy, but they do not contribute to the quality of the sample itself.

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

C. Quota

A nurse researcher is studying the relationship between gender and stress level after cardiac surgery at a local hospital where males having cardiac surgery constitute 55% of cardiac surgery patients. The study sample constituted of 20% males and 80% females. This situation might lead to: A. History threat B. Mortality threat C. Sampling bias D. Maturation threat E. Enhanced external validity

C. Sampling bias Feedback: Sampling bias refers to the systematic over- or underrepresentation of a population segment on a characteristic relevant to the research question. In this case, it appears that men will be systematically underrepresented, and a person's gender might play a role in medication compliance. The situation described would not lead to revisions of the eligibility criteria or the definition of the target population. The use of multistage sampling is irrelevant to the circumstances in this example.

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

D) Systematic over or underrepresentation of a key attribute

A nurse researcher studying stress levels among nursing students during exams recruits study participants by placing a recruitment poster at the entrance to the classroom. Which sampling approach did the researcher use in this study? A. Consecutive sampling B. Snowball sampling C. Quota sampling D. Convenience sampling

D. Convenience sampling Feedback:In this example, the researcher used the most conveniently available people as study participants. The use of a recruitment poster meant that only people who entered the healthcare center, took notice of the poster, and then volunteered for the study would become participants. This is not an example of quota, snowball, or consecutive sampling.

True or False "In Johnston et. al. (2018) study, the sample size was based on pilot data from one PICU site."

True

Yes or No In Johnston et. al. (2018) study, was the sample size calculated based on power analysis?

Yes