Chapter 9 Selecting the Sample & Setting (Quantitative))

Question 1

Population

Answer 1

A well-defined group whose members possess specific attributes

Question 2

Target Population

Answer 2

The group being studied
-Eligibility criteria

Question 3

Inclusion Criteria

Answer 3

The key features of the target population that the investigators will use to answer their research question

Question 4

Exclusion Criteria

Answer 4

Features of the potential study participants who meet the inclusion criteria but present with additional characteristics that could interfere with the success of the study or increase their risk for an unfavorable outcome

Question 5

Sample

Answer 5

Small subset of a population

Question 6

Select Sample

Answer 6

Representative of the population

Question 7

Sampling

Answer 7

Process of selecting individuals for a study

Question 8

Probability Sampling

Answer 8

“Random Sampling”

Question 9

Simple Random Sample

Answer 9

Every subject has an equal & independent chance of being chosen

Question 10

Cons of Simple Random Sampling

Answer 10

Can be time-consuming

More pricey

Difficult, or impossible, to obtain an accurate or complete sampling frame of every element in accessible population

Question 11

Stratified Random Sampling

Answer 11

Selecting a sample to identify subgroups in the population that are represented in the sample

Question 12

Advantages of Stratified Random Sampling

Answer 12

Achieves greater degrees of representation w/in population

Question 13

Cluster (Multistage) Sampling

Answer 13

Groups, not individuals, are randomly selected

Used for convenience in:
o large populations
o populations spread over large geographic area

Question 14

Systematic Sampling

Answer 14

Individuals or elements of the
population are selected from a list by
taking every kth individual

Each member does not have an
independent chance of inclusion

Considered random sampling if list is
randomly ordered 1st

Data collected conveniently and
efficiently

Question 15

Non-probability Sampling

Answer 15

“Non-random Sampling”

Chance plays no role in
determination of sample

Limits ability to make
generalizations about findings

Many nursing research studies use
non-probability sampling because of
difficulties in obtaining random
access to populations

Question 16

Convenience Sampling

Answer 16

Collection of data from subjects that are readily available or easily accessible to the researcher

Question 17

Advantages of Convenience Sampling

Answer 17

Easy to carry out
Cost-efficient

Question 18

Disadvantages of Convenience Sampling

Answer 18

Potential for bias
Limited ability for results to be generalized

Question 19

Snowball (network) Sampling

Answer 19

Useful when list of individuals who share particular characteristic cannot be obtained

Researchers ask subjects to help them get in touch w/other potential subjects

Question 20

Quota Sampling

Answer 20

Identifies the strata of the population based on specific characteristics

Quota is computed proportionally or
disproportionally to the population under study

Question 21

Purposive Sampling

Answer 21

Researcher “handpicks” or selects certain cases thought to be best representatives to be included
in the study

Commonly used in qualitative research

Question 22

How do you determine sample size for quantitative study?

Answer 22

Have a large enough sample size to be representative of the population but, not too large not to gain sufficient information

Question 23

What are quantitative studies determined by?

Answer 23

Power Analysis

Question 24

Power Analysis

Answer 24

The calculation used to estimate the smallest sample size needed for an experiment, given a required significance level, statistical power, and effect size

Question 25

What occurs if the sample size is too small?

Answer 25

Results in insufficient power to determine differences among groups

Question 26

What are qualitative studies determined by?

Answer 26

Data Saturation

Question 27

Data Saturation

Answer 27

The point in a research process where enough data has been collected to draw necessary conclusions, and any further data collection will not produce value-added insights

Question 28

External Validity

Answer 28

Extent to which study results can be generalized from the study sample to other subjects, populations, measuring instruments, & settings

Question 29

Threats to External Validity

Answer 29

Interaction of Sample & Treatment: Samples confined to certain types of subjects Interaction of setting and treatment: Bias when members of different settings agree to participate Interaction of history and treatment: Concerns about ability to generalize results to different periods of time in the past or future

Question 30

Natural Setting

Answer 30

Uncontrolled, real-life situation

Question 31

Partially-Controlled Setting

Answer 31

Manipulated or modified in some way

Question 32

Highly Controlled Setting

Answer 32

Artificial environment for sole purpose of doing research. Decreases effects of outside influences.

Question 33

Quantitative Data Collection

Answer 33

Numerical Formulated into tables or counts Analyzed without extreme effort Data collection involves use of instruments

Question 34

Surverys

Answer 34

Self-admin May be mailed or conducted face-to-face

Question 35

Questionnaires

Answer 35

Closed-ended Open-ended

Question 36

Psychometric Assessment

Answer 36

Evaluates the measure's measurement properties

Question 37

Reliability

Answer 37

Extent to which scores are free from measurement error

Question 38

Test-Retest Reliability

Answer 38

Admin a measure to the same people on 2 occasions

Question 39

Interrater Reliability

Answer 39

Having 2 or more observers independently apply the measure w/ same people to determine consistency

Question 40

Internal Consistency Reliability

Answer 40

Extent that the items measure the same trait across items on scales

Question 41

Reliability Coefficient Scale

Answer 41

Range from .00 to 1.00 with .80 or higher is acceptable

Question 42

Chodos randomly assigned 50 men and 50 women smokers (who had responded to an online recruitment notice) to a smoking cessation intervention or to a control group. Probability or Non-probability

Answer 42

Non-Probability The sample was a quota sample; men & women responded to a notice and were not selected at random

Question 43

Solomons studied circadian rhythms in a sample of 45 pregnant women consecutively admitted to a hospital in the first 6 months of 2016 because of severe preeclampsia. Probability or Non-Probability?

Answer 43

Non-Probability The sample was a consecutive sample of patients meeting eligibility criteria; they were not selected at random

Question 44

Kane randomly sampled 250 nurses from urban areas and 250 from nonurban areas from a roster of licensed nurses in Florida to study their attitudes toward evidence-based practice Probability or Non-pProbability?

Answer 44

Probability

Question 45

Marshall randomly selected 250 students from a large university to study their use of drugs and alcohol. Probability or Non-Probability?

Answer 45

Probability The sample was a simple random sample of students, presumably students were selected at random.

Question 46

Rocco administered her self-efficacy scale to 50 patients twice, 1 week apart. The coefficient between the two sets of scores was .82. Reliability or Validity?

Answer 46

Reliability

Question 47

Rogers examined the relationship between scores on a self-report insomnia scale and sleep efficiency indexes as measured by an Actiwatch wristband. Reliability or Validity?

Answer 47

Validity Rogers was assessing criterion validity by using the Actiwatch wristband

Question 48

Pfortmiller assessed the degree to which the 12 items on his resilience scale measured a unitary attribute; he calculated a coefficient of .91. Reliability or Validity?

Answer 48

Reliability Pfortmiller was assessing the internal consistency reliability of his scale.

Question 49

Blalock compared scores on her Breastfeeding Anxiety Scale for two groups: women in their first pregnancy and women who were lactation consultants. Reliability or Validity?

Answer 49

Validity Blalock was using the known-groups technique to assess the construct validity of her scale.

Question 50

Casey randomly assigned 152 elders recruited from 5 nursing homes

Question 51

Rocco administered her self-efficacy scale to 50 patients