Question 1

A study's sampling plan can compensate for a

Accepted Answer

A study's sampling plan can compensate for a design's shortcomings in controlling for threats to validity, such as lack of randomization to groups. Sampling decisions are affected by ethical considerations and link to almost every other element in a study to identify the time and resources needed.

Question 2

The general term for describing individual units of a sample is

Accepted Answer

The individual units of a population are referred to as elements. Informants are elements in a qualitative study and respondents are elements in survey research.

Question 3

A nurse research team conducting a study about perceptions of body changes after a stroke sought participants who (1) were female, (2) were over age 65, (3) could read and speak English, and (4) had no serious cognitive or linguistic deficit. In this case, a "cognitive or linguistic deficit" constitutes a(n)

Accepted Answer

Exclusion criteria identify characteristics that disqualify an individual (or other element) from being included in a study. Inclusion and qualifying criteria identify characteristics of those who will be sought as study participants.

Question 4

"All nursing students who smoke" is an example of a

Accepted Answer

Eligibility criteria designate the characteristics that are required for membership in the study population. In this study, nurses who smoke would be eligible for membership in the population. The subset of elements that actually participate in a study is the sample. A stratum of a population is a mutually exclusive segment of the population that is established on the basis of one or more characteristics.

Question 5

If a population was defined as "American men who have had coronary artery bypass surgery," one possible stratum would be

Accepted Answer

A stratum of a population is a mutually exclusive segment of the population that is established on the basis of one or more characteristics. In this case, the characteristics are "men under 50 who have had bypass surgery." Men who have never had surgery and women who have had surgery are populations.

Question 6

If a population was defined as "Russian immigrant children attending elementary school in Spokane," an element would be

Accepted Answer

The individual units of a population are referred to as elements. "Elementary school in Spokane" and "children who are Russian" are not individual units. "Elementary school in Spokane" and "elementary school children in Spokane who are Russian" would be inclusion criterion.

Question 7

Sampling bias refers to bias resulting from

Accepted Answer

Sampling bias refers to the systematic over-representation or under-representation of some segment of the population in terms of a characteristic that could affect the dependent variable. Inappropriate specification of eligibility criteria and a sample that is too small would affect validity.

Question 8

A researcher who is studying stress management techniques used by nursing students samples every twentieth student on an enrollment roster. This method of sampling is referred to as

Accepted Answer

Systematic random sampling is a variation of simple random sampling that can be used when the sampling frame has no meaningful underlying order or pattern of arrangement.In network sampling (sometimes called snowball sampling), initial sample members are asked to identify and refer or recruit others who meet the eligibility criteria into the study. Quota sampling can be thought of as stratified convenience sampling.

Question 9

A researcher who is studying grief among individuals who have divorced a gay/lesbian spouse obtains a sample by asking study participants if they know of anyone else who has divorced for this reason. This method of sampling is referred to as

Accepted Answer

Snowball sampling (network sampling) asks initial sample members to identify and refer or recruit others who meet the eligibility criteria into the study. A convenience sample (sometimes called an accidental sample) is comprised of elements that meet established eligibility criteria and are conveniently available to the researcher. In purposive sampling, the researcher uses personal knowledge of a population to consciously select (hand-pick) the elements that will constitute the study sample.

Question 10

A research team studied alcohol use among nursing students at private universities. The first sampling selected eight states, then randomly selected two universities in each state, and then randomly sampled students from each program. This sampling process is referred to as

Accepted Answer

Cluster sampling is a variation of random sampling that is used when the population of interest is geographically widely scattered and it would be difficult, if not impossible, to develop a sampling frame. In purposive sampling, the researcher uses personal knowledge of a population to consciously select. Systematic sampling is a variation of simple random sampling that can be used when the sampling frame has no meaningful underlying order.

Question 11

Which type of sample carries the greatest risk for sampling error?

Accepted Answer

Cluster sampling carries the greatest risk for sampling error because it is done in two or more stages. Stratified random and systematic sampling is done in one stage.

Question 12

Sampling error is smaller in

Accepted Answer

Sampling error is smaller in homogeneous samples because elements are very similar in characteristics. Random and small samples have greater potential for error in sampling.

Question 13

A pair of nurse researchers recruited participants for their qualitative study about resilience in elderly women who had never married by posting flyers about their study in area churches. This method of sampling is referred to as

Accepted Answer

Convenience sampling entails recruiting participants who are in the right place at the right time, which would be the case with recruiting from church members. In purposive sampling, the researcher uses personal knowledge of a population to consciously select. Referral sampling is when the researcher seeks participant referral from current participants.

Question 14

A researcher recruits study participants from students using the nursing library on weekends. The first 50 junior students and the first 50 senior students are asked to complete a survey. This method of sampling is referred to as

Accepted Answer

This is an example of quota sampling. Once 50 are obtained the data collection is complete. In purposive sampling, the researcher uses personal knowledge of a population to consciously select study elements. Stratified random sampling entails randomly sampling from identified population strata.

Question 15

A researcher randomly draws the names of 100 nurses from a list of all nurses who have been employed full-time for at least 5 years at the study hospital. This list of nurses constitutes

Accepted Answer

A sampling frame is a complete list of all of the elements in the population to be studied. An accessible population is that portion of a population that is available as a sample. Probability sampling is another term for random sampling.

Question 16

Which is true when estimating sample size needs for a quantitative study?

Accepted Answer

Ideal sample size usually is based on either the Central Limit Theorem or power analysis. The CLT (which has been proven mathematically) asserts that the mean of a randomly generated sample of 30 or more elements approximates the population mean for any characteristic (Hinkle et al., 2003). Sample size has a major effect on a study's statistical conclusion validity, or the believability of the study's statistical findings, but cannot compensate for weakness in design. Larger samples are needed in experimental research.

Question 17

The procedure that should be used to calculate needed sample size in a quantitative study is

Accepted Answer

Power analysis is a statistical process used in quantitative research for identifying the sample size needed to detect statistical significance, given a stated effect size. Stratification and weighting are incorrect. Stratification is a control strategy and weighting would be an analysis approach.

Question 18

The overriding criterion for sampling adequacy in a qualitative study is

Accepted Answer

The logic and power of a qualitative sample is determined by the quality of information per element, rather than by the number of elements (Morse, 1991). Representativeness and sample size may be considered, but are not the overriding criterion.

Question 19

In quantitative studies, a larger sample is needed when the

Accepted Answer

A larger sample is needed when the expected incidence of a phenomenon is expected to be small. When the difference between groups is expected to be large or the population is homogeneous, a smaller sample size is indicated.

Question 20

A team of qualitative nurse researchers makes an effort to include men and women of different ages and ethnic groups in their sample. This reflects

Accepted Answer

This example shows maximum variation sampling from gender, age, and ethnicity.Homogeneous sampling and typical case sampling refer to groups with similar elements.

Quiz 9: Research Samples