chapter 13 choosing a sample

Question 1

1st step in planning a study is finding the _______ population

Answer 1

target

Question 2

Target population must be Identified, which can be stated as the _______ population

Answer 2

accessible

Question 3

target population&raquo_space; _______

Answer 3

accessible population

Question 4

When the differences between the target and accessible population are too great, i.e., geographic differences like climate or socioeconmic characteristics, it may be necessary to get more _______ target population

Answer 4

restricted population

Question 5

SELECTION CRITERIA: 2 types. Inclusion criteria and ______ criteria

Answer 5

exclusion

Question 6

once we identified a target population, we have to plan for subject _______ , inviting individuals to participate.

Answer 6

recruitment

Question 7

the ______ sample of people may be less than predicted/requested

Answer 7

FINAL

Question 8

t/f, A flow chart that details how participants pass through various stages of a study should be included in a research report. This is an example of “reporting subject participation”.

Answer 8

t

Question 9

Sample size is directly related to ________ of the study

Answer 9

POWER

Question 10

With a small sample, power tends to be low and a study may not succeed in demonstrating the desired effects. t/f

Answer 10

t

Question 11

larger sample = probably more POWER of a study, true or false

Answer 11

true

Question 12

Probability samples are created through a process of ______ sampling/selection.

Answer 12

random

Question 13

random selection/sampling

Answer 13

every unit in the population has an equal chance, or probability of being chosen

Question 14

nonprobability samples

Answer 14

made by non random methods, usually used more in clinical research

Question 15

sample values

Answer 15

statistics

Question 16

population values

Answer 16

parameters

Question 17

difference between sample values and population values

Answer 17

sampling error, sampling variation

Question 18

the essence of random sampling is that these sampling differences are due to ______ and are not a function of any human bias, conscious or unconscious.

Answer 18

chance

Question 19

Random selection/sampling gives the greatest possibility of a samples validity, t/f

Answer 19

t

Question 20

sampling bias: conscious vs unconscious

Answer 20

conscious: the people selected for a sample overrepresent or underrepresent certain population attributes that are related to the phenomenom of the study
unconscious: u pick people who look handicap for a handicap study

Question 21

Probability sampling :

Answer 21

every member of a population has an equal opp, or probability, of being selected

Question 22

a truly RANDOM SAMPLE is unbiased in that each selection is independent and no one member of the population has any more chance of being chosen than any other member, t/f

Answer 22

t

Question 23

There are many different types of sampling, examples?

Answer 23

Probability methods
simple, systematic, stratified random, cluster, disproportional
non probability methods
convenience, quota, purposive, snowball

Question 24

Non probability sampling methods examples

Answer 24

1. Convenience Sampling - use of available participants e.g.,
   college students or community volunteers who respond to the flyers;
   Most frequently used sampling method
2. Purposive Sampling – used when specific expertise /
   experience of participants is needed
   ▪ often used in qualitative studies
3. Quota Sampling – incorporate a stratification but lack of a
   randomization
4. Snowball Sampling – used when it is difficulty to find subjects
   ▪ to recruit via communication of “word-of-mouth”

Question 25

Convenience Sampling NP

Answer 25

use of available participants e.g.,
college students or community volunteers who respond to the flyers;
Most frequently used sampling method

Question 26

Purposive Sampling NP

Answer 26

used when specific expertise /
experience of participants is needed
▪ often used in qualitative studies

Question 27

Quota Sampling NP –

Answer 27

incorporate a stratification but lack of a
randomization

Question 28

Snowball Sampling NP

Answer 28

– used when it is difficulty to find subjects
▪ to recruit via communication of “word-of-mouth”

Question 29

simple random P

Answer 29

each member has an equal chances of being selected

Question 30

systematic sampling P

Answer 30

Systematic sampling is a probability sampling method where researchers select members of the population at a regular interval – for example, by selecting every 15th person on a list of the population. If the population is in a random order, this can imitate the benefits of simple random sampling

Question 31

stratified random sampling P

Answer 31

a population divides into strata or subsets, and then the random sample is taken from each stratum in proportion to its size. For example, if the entire population is 60% female and 40% male, then the sample would be 60% female and 40% male.

Question 32

cluster sampling P

Answer 32

researchers divide a population into smaller groups known as clusters. They then randomly select among these clusters to form a sample. Cluster sampling is a method of probability sampling that is often used to study large populations, particularly those that are widely geographically dispersed

Question 33

Disproportional sampling P

Answer 33

a form of stratified random sampling, a sampling technique where the sample size for each group, or stratum, is not proportional to the size of that group in the overall population. Instead, the sample size for each group is based on specific research needs. These strata are oversampled to provide stronger representation, and weights are used to adjust data to correct this