CH 10

Why Sample? what is the purpose of sampling

draw conclusions accurately about a population based on information from a sample

____ research is Sampling based on desire to have a representative sample ___ research is Sampling based on desire to obtain data representative of phenomenon of interest

quantitative qualitative

A nurse wishes to explore the attitudes of critical care nurses towards family presence during resuscitation. She selected for interview 10 nurses who favored family presence and 10 who did not. This is an example of which sampling method? A. Snowball Sampling B.Convenience C. Theoretical D. Purposive

D

A total of 20 nursing students are randomly selected from a random sample of five nursing programs in one state. Which of the following would be the largest of the groups? A. Accessible population B. Control group C. Sample D. Target population

D

In a study of nursing students' attitudes toward caring for patients with hypertension who are noncompliant with their medications, the researcher randomly selected a sample of nursing students from a list of all students enrolled in each of five nursing programs that had been randomly selected from one state. Because the sample was randomly selected, to which population can the findings be generalized? A. Nursing students in the programs that were randomly selected B.Nursing students in the state from which the programs were randomly selected C.Nursing students in the United States D. All nursing students

D

Which of the following would be the strongest method for assigning 50 subjects to treatment and control groups in an experimental study? A.Group subjects according to attending physician. B.List subjects alphabetically, divide the list in half, place the first 25 names in the treatment group and the last 25 in the control group. C.Assign each participant a number, place even numbered participants in the treatment group and the odd numbered in the control group. D.Assign each participant a number, place the numbers in a box, draw numbers from the box, alternating placement in either the treatment group or the control group.

D

concepts related to sampling: (define each one) -population -target population -accessible population -sample

-population: elements that eat specified criteria -target population: set encompasses every element in the world that met the sampling criteria -accessible population: portion of the target population that the investigator can reasonably reach -sample: elements from whom or about whom data are actually collected

The 2 concerns for sampling is: -representative sample: -sampling error: define them

-representative sample- one that looks like the target population in terms of important characteristics -sampling error-difference between data obtained from the sample and data that would be obtained if the entire population was included

nonprobability sampling: •Convenience sampling •Quota sampling •Purposive sampling •Snowball sampling •Theoretical sampling

1) nonporbability sampling- use of a non-random sampling approach 2) Convenience sampling-sample compromised of people accessible to the researcher (accidental sampling) 3) Quota sampling-strata 4)Purposive sampling- judgement 5)Snowball sampling- each participant is recommenced to add more participants 6) Theoretical sampling- selecting new participants based on emerging findings from previous data

How to Sample? Probability Sampling: •Random sampling •Simple random sampling •Stratified random sampling •Cluster sampling sampling •Systematic random sampling

1) probability sampling- use of random sampling approaches 2) Random sampling- equal opportunity 3) Simple random sampling- lists all participants then selects 4) Stratified random sampling- simple random but divided again 5) Cluster sampling sampling- multistage 6)Systematic random sampling

How many to sample? (Quantitative)

1. population 2.design 3.measurement 4.practical factors

(Qualitative)

1. small 2.nonrandom

In interpreting quantitative research results, the representatives of the sample is most closely tied to. A.Internal validity. B.External validity. C.Sample validity. D.Research validity.

A

Which of the following samples is least likely to be representative of the overall population? A. Convenience B. Quota C. Random D. Stratified Random

A

Which of the following types of studies would require the largest sample size? A. Correlational study B. Ethnography C. Grounded theory D. Phenomenology

A

A researcher has decided to conduct a satisfaction survey among all the patients who presented to the emergency department over a 2-month period of time. This is an example of A.Stratified random sampling B.Cluster Sampling C. Convenience Sampling D.Purposive Sampling

A

A total of 20 nursing students are randomly selected from a random sample of five nursing programs in one state. Which of the following would be the largest of the identified groups? A. Accessible Population B. Control Group C. Sample D. Target Population

A

SATA: A sample included 473 women: 106 had unplanned cesarean deliveries, 113 had planned cesarean deliveries, and 254 had vaginal deliveries. All of the women who had vaginal deliveries and the majority (79%) who had unplanned cesarean deliveries were recruited from childbirth education classes. The sample was predominantly white, and all subjects spoke English, had no major prenatal complications or underlying medical problems, and delivered healthy full-term infants. Which of the following represent sample characteristics? A. Type of delivery B. Predominantly White C. Spoke English D. Recruited from childbirth classes

A B C

A researcher who wished to study the impact of having a child with cystic fibrosis on family functioning contacts the local CF foundation for assistance in finding parents to interview. Parents of children with CF on the local chapter are the A. Target population B.Accessible population C.Sample D.Participants

B

A total of 20 nursing students are randomly selected from a random sample of five nursing programs in one state. This is an example of what type of sampling? A. Simple random B. Cluster C. Convenience D. Purposive

B

Which of the following studies would require the largest sample size? A.A study which the population is homogenous B. A study that involves multiple Variables C. A study measuring interval-level variables D. A study using cluster sampling

B

A researcher's decisions related to sampling affect which of the following? Choose all that apply. A. Internal consistency B. Internal Validity C. External Validity D. Choice of target population

B C

A nurse researcher who is interested in studying the career paths of deans in nursing programs approached six deans whom she knew had been active in the American Association of Colleges of Nursing and asked them to participate in her study. This sampling strategy reflects: A. Convenience Sampling B. Network Sampling C. Purposive Sampling D. Inappropriate Sampling

C

A power analysis determined that a sample size 196 would provide a power of 0.80 with anlpha less than 0.05. The study enrolled 202 subjects. Is the sample size adequate, and why? A. No, because the power achieved with a sample size of 196 is only 0.80. B.No, because the power achieved with a sample size of 196 is only 0.80. C.Yes, because the sample size was supported by a power analysis. D.Yes, because 202 subjects were included, way more than the minimum of 30.

C

A sample that Accurately reflects the characteristics of the population is known as A. Random Sample B. Purposive Sample C. Representative Sample D. Probability Sample

C

Determination of appropriate sample size in qualitative research is based on the principles of: A. Power analysis B. The rule of 30 C. Saturation and Redundancy D. Convenience and access

C

when is determination of an adequate sample size in qualitative research determined ?A. A power analysis indicates the power is 0.70 B.The sample size is large enough to identify differences in groups C. Saturation and redundancy of data are achieved D. A sample size of 30 is obtained

C

Whom to Sample? The investigator must make 2 different types of decisions- who should be considered for ____ in the same and who should be___ from the sample

included criteria excluded criteria

2 key elements in evaluating quantitative research are issues related to the ___ and ___ validity

internal external