211 Unit #3 Sampling

Question 1

Bias is a problem because it:

Select one:

a. Increases sample size
b. Decreases generalizability
c. Increases effect size
d. Decreases normality

Answer 1

b. Decreases generalizability

Question 2

Which of the following statements are true?

Select one:

a. No matter which sampling method is used, sampling error will always exist due to chance alone
b. Sampling error can be reduced by recruiting a larger sample
c. Sampling error can be reduced by obtaining a random sample
d. All of the above

Answer 2

d. All of the above

Question 3

When setting up a plan to recruit a sample, researchers develop inclusion and exclusion criteria to increase the ______________ of the sample.

Select one:

a. Homogeneity
b. Efficiency
c. Reliability
d. Median

Answer 3

a. Homogeneity

Question 4

Researchers use the desired power of a study to calculate

Select one:

a. Generalizability
b. Alpha
c. Reliability
d. Sample size

Answer 4

d. Sample size

Question 5

Are effect size and sample size related?

Select one:

a. No, effect size depends only on inclusion and exclusion criteria
b. Yes, If the effect size is small, a smaller sample size is needed to find a difference between variables if one exists
c. No, sample size depends only on alpha
d. Yes, if the effect size is small, a larger sample size is needed to find a difference between variables if one exists

Answer 5

d. Yes, if the effect size is small, a larger sample size is needed to find a difference between variables if one exists

Question 6

Individuals who provide data in research study are often referred to as the:

Select one:

a. population.
b. data points.
c. coding plan.
d. sample.

Answer 6

d. sample.

Question 7

A study was conducted to determine whether head flattening in preterm infants was prevented by placing their heads on a water pillow. The first 50 preterm infants admitted to a newborn intensive care unit during a specific year were assigned to either a usual care group or a treatment group. What type of sampling strategy is represented by this research plan?

Select one:

a. Quota
b. Random
c. Purposive
d. Stratified

Answer 7

c. Purposive

Question 8

What is the major benefit of nonprobability sampling, as compared with probability sampling?

Select one:

a. It does not affect generalizability.
b. Informed consent must be obtained.
c. The necessary sample sizes are easier to obtain.
d. Sample sizes are too small for most methods of statistical analysis

Answer 8

c. The necessary sample sizes are easier to obtain.

Question 9

Which factor or condition of a sample meets the criterion for representativeness?

Select one:

a. The sample is drawn randomly from the general population without the use of specific criteria.
b. The characteristics of the sample closely resemble the characteristics of the larger target population.
c. The sample includes the same percentage of men and women as well as members of different ethnic groups as does the general population.
d. The subjects selected for the sample have agreed to express the specific opinions or beliefs representative of their ethnic or cultural group.

Answer 9

b. The characteristics of the sample closely resemble the characteristics of the larger target population

Question 10

What type of sampling strategy is represented when every fourth postsecondary student who registers for a specific course is selected into the treatment group?

Select one:

a. Cluster sampling
b. Systematic random sampling
c. Simple random sampling
d. Stratified random sampling

Answer 10

b. Systematic random sampling

Question 11

Describe non-probability sampling

Answer 11

the sample is selected based on non-random criteria, and not every member of the population has a chance of being included

Question 12

What are the 4 types of non-probability sampling

Answer 12

convenience sampling, quota sampling, purposive sampling, and network sampling

Question 13

What is convenience sampling and an example

Answer 13

using the most readily accessible persons ie. first 30 volunteers

Question 14

What is quota sampling and an example

Answer 14

systematically ensures that proportional segments of the population are included in the sample ie. if ur population is 45% female and 55% male ur sample needs to reflect those numbers

Question 15

Describe purposive sampling

Answer 15

subjects are selected because they are identified as knowledgable regarding the subject under investigation

Question 16

describe network sampling

Answer 16

selected within a network to locate subjects difficult to obtain

Question 17

Describe probability sampling

Answer 17

randomized sample where every element of the population has an equal chance for selection

Question 18

_____ increases generalizability

Answer 18

probability sampling

Question 19

_____ decreases generalizability

Answer 19

non-probability sampling

Question 20

4 types of probability sampling

Answer 20

simple random sampling, stratified random sampling, cluster random sampling, systematic random sampling

Question 21

describe simple random sampling

Answer 21

controlled process; each random selection is independent of the next selection

Question 22

In simple random sampling representation _____ as the sample size ______

Answer 22

increases; increases

Question 23

describe stratified random sampling

Answer 23

division of a population into smaller sub-groups known as strata based on members shared attributes

Question 24

Describe cluster random sampling

Answer 24

random sampling of clusters from large t small clusters of individuals who meet the criteria

Question 25

describe systematic random sampling and an example

Answer 25

subjects are randomly selected at fixed intervals that are predetermined ie. lucas can give a survey to every fourth customer in line at a movie theatre

Question 26

because of _____ and _______ samples are seldom truly representative of the population from which they are drawn

Answer 26

error; bias

Question 27

error is _______

Answer 27

due to chance

Question 28

describe bias

Answer 28

systematic errors that are introduced by the researcher that fail to account for factors that may influence the outcome of the study

Question 29

larger sample size = ______

Answer 29

greater power

Question 30

describe effect size

Answer 30

the magnitude of the difference between the outcomes obtained from an intervention