P&B Chapter 12: Quant Research: Sampling, Data Collection, Measurement and Data Quality

Question 1

N =

Answer 1

N = Population: entire aggregation of cases in which the researcher is interested

Question 2

n =

Answer 2

n = sample: subset of population elements

Question 3

2 key considerations of representative quantitative sample

Answer 3

1) representativeness

2) size

Question 4

Quantitative sample size can be determined by _____ _______.

Answer 4

power analysis

Question 5

What specifies population criteria?

Answer 5

eligibility criteria
examples: TBI with at least 5 days inpatient rehab;
diagnosis of Diabetes;
participant of Rebuilding Together

**sometimes a population is also defined by characteristics that people must NOT possess (exclusion criteria)

Question 6

List at least 4 considerations for eligibility?

Answer 6

1) cost
2) practical constraints
3) people’s ability to participate
4) design considerations (remember designs from Quiz 1)

Question 7

Which type of sample? Probability or Non-Probability

* elements selected by non-random methods

Answer 7

non-probability

Question 8

Which type of sample? Probability or Non-Probability

*involves random sampling

Answer 8

probability

Question 9

Which type of sample? Probability or Non-Probability

*no way to establish probability that each element will be included in sample

Answer 9

non-probability

Question 10

Which type of sample? Probability or Non-Probability

*estimates probability that an element will be included in sample

Answer 10

probability

Question 11

4 types of non-probability sampling

Answer 11

1) Convenience sampling**
2) Quota sampling
3) Consecutive sampling
4) Purposive sampling

**Snowball sampling is a TYPE of convenience sampling (pg. 276 in the book lists convenience, quota, consecutive, & purposive as the 4 types though :) )

Question 12

Which type of non-probability sampling?

1) Convenience sampling
2) Quota sampling
3) Consecutive sampling
4) Purposive sampling
5) Snowball sampling
* network or chain sampling by referral

Answer 12

Snowball sampling

Question 13

Which type of non-probability sampling?

1) Convenience sampling
2) Quota sampling
3) Consecutive sampling
4) Purposive sampling
* recruiting all from accessible population over specified time and size

Answer 13

Consecutive sampling (can be selected retrospectively or prospectively)

Question 14

Which type of non-probability sampling?

1) Convenience sampling
2) Quota sampling
3) Consecutive sampling
4) Purposive sampling
* researcher uses knowledge about population to select sample

Answer 14

purposive sampling

Question 15

Which type of non-probability sampling?

1) Convenience sampling
2) Quota sampling
3) Consecutive sampling
4) Purposive sampling
* using those who are most available as participants

Answer 15

convenience sampling

pretty much the hallmark of non-probability sampling

Question 16

4 types of probability sampling

Answer 16

I. simple random sampling
II. stratified random sampling
III. multicluster sampling
IV. systematic sampling

Question 17

Which type of probability sampling?
I. simple random sampling
II. stratified random sampling
III. multicluster sampling
IV. systematic sampling
* selecting every \_\_\_th case from a list; sample interval

Answer 17

systematic sampling

Question 18

Which type of probability sampling?
I. simple random sampling
II. stratified random sampling
III. multicluster sampling
IV. systematic sampling
* selecting broad groups in stages than randomly selecting sample

Answer 18

multistage cluster sampling

ex: OT students in US, then create regions, then random selection

Question 19

Which type of probability sampling?
I. simple random sampling
II. stratified random sampling
III. multicluster sampling
IV. systematic sampling
*subdivide population into homogeneous subtests then randomly select sample; proportionate vs. disproportionate

Answer 19

stratified random sampling

need large population to start with so that you can random sample from that

Question 20

In Probability sampling, what error/bias is described?

*difference between population values and sample’s value

Answer 20

sampling error

Question 21

In Probability sampling, what error/bias is described?

*systematic over-representation or under-representing of population segment; based on population’s homogeneity

Answer 21

sampling bias

Question 22

Place the steps in sampling quantitative studies in order:
A. recruit the sample
B. identify the population
C. specify sampling plan (to include method of drawing sampling and power analysis)
D. specify eligibility criteria

Answer 22

1. B. identify the population
2. D. specify eligibility criteria
3. C. specify sampling plan (to include method of drawing sampling and power analysis)
4. A. recruit the sample

Question 23

“Researchers usually sample from an _______ population, but should identify the ______ population to which they want to generalize their results”

Answer 23

accessible, target

Question 24

Can you name one positive/strength of nonprobability sampling? What about one negative?

Answer 24

Positive: practical
Negative: strong potential for bias

Question 25

Can you name one positive/strength of probability sampling? What about one negative?

Answer 25

Positive: best method for obtaining a representative sample (if the sample isn't representative of the population, the study's external validity and construct validity are at risk) Negative: impractical/laborious

Question 26

What does this describe: it specifies in advance how participants are to be selected and how many participants to include

Answer 26

Sampling plan

Question 27

True or False - samples are sometimes selected in multiple stages

Answer 27

True (multistage sampling) - For example, in the first stage, large units are selected (nursing homes); then in a later stage, individual people are selected the first stage can involved deliberate selection of the study site (nursing homes) and then people within the nursing homes can be randomly selected = a way to combine probability/nonprobability sampling together

Question 28

True or False - "The probability of selecting a deviant sample size INCREASES as the size of the sample DECREASES"

Answer 28

False - the deviant sample size DECREASES as the sample size gets bigger and bigger (becomes more representative)

Question 29

True or False - "The LARGER the sample, the SMALLER the sampling error"

Answer 29

True

Question 30

Fill in the blank - "Power analysis builds on the concept of _______ _____, which expresses the strength of relationships among research variables"

Answer 30

effect size (so, if there is reason to believe that the IV and the DV will be strongly related, then a relatively small sample may be adequate to reveal the relationship statistically)

Question 31

True or False - "If the population is relatively HOMOGENEOUS, a small sample size may be adequate"

Answer 31

True

Question 32

When is attrition in a study most likely to occur (when people drop out of the study)?

Answer 32

1) if the time lag between data collection points is great 2) if the population is mobile 3) if the population is at risk of death or disability