Chapter 4

Question 1

participant

Answer 1

When the unit of data is an individual, we refer to that individual as a participant

Question 2

______________ means the same thing as participant

Answer 2

Subject

Question 3

_________________ always use the term participant

Answer 3

Qualitative studies

Question 4

sample

Answer 4

is the collection of participants from whom data have been collected in a study

Question 5

population (or target population or universe)

Answer 5

is the group of individuals to whom we wish to generalize the results of our study

Question 6

Delimiting variables

Answer 6

the characteristics (e.g., gender, grade, subject matter) that define the population

Question 7

Survey population or Sampling frame

Answer 7

the list of actual individuals you will choose your sample from. While the population may be theoretical, the survey population must be finite

Question 8

Random Sampling

Answer 8

A technique in which each member of the survey population has an equal chance of appearing in the sample. Random sample will represent their populations if the sample size is large enough.

Question 9

Margin of Error

Answer 9

An interval within which the true population value lies. Typical values are 95% and 99% confidence intervals.

Question 10

Simple Random Sampling

Answer 10

Every member of the population is enumerated. The sample is randomly selected from this list.

Question 11

Systematic Sampling

Answer 11

Every nth element of the sampling frame is selected for inclusion in the sample.

Question 12

________________ can be biased if some characteristic of the sampling frame is related to the sampling cycle. So if you choose every 30th student, and class sizes are just over 30, you may always choose a student in the back of the class.

Answer 12

Systematic sampling

Question 13

Stratified Sampling

Answer 13

Certain characteristics (i.e., strata) of the population are identified for representation in the sample. Once the strata are identified, they are represented in the sample at the same percentage as they exist in the population (proportional stratified sample). The strata are filled through a random sampling procedure. It is also possible to represent strata in percentage different than they exist in the population (e.g., whites and blacks at 50% each; disproportional stratified sampling). This might be done when certain subgroups are to be compared in later analyses.

Question 14

Cluster Sampling

Answer 14

The sampling of naturally occurring groups (i.e., clusters) of participants. Participants can then be drawn randomly from the sampled clusters (e.g., students from within classrooms). This procedure works, but special statistical techniques (e.g., hierarchical linear modeling) must be used to analyze the data, since participants from within a cluster are more similar to each other than participants from different clusters.

Question 15

In non-probability sampling . . .

Answer 15

the probability of each individual in the survey population being included in the sample is not equal.

Question 16

________________ typically use non-probability sampling techniques

Answer 16

Qualitative studies

Question 17

Convenience Sampling

Answer 17

The sample is selected because of its easy availability. Typically, convenience samples will be biased.

Question 18

Quota Sampling

Answer 18

Basically, this is a stratified sampling approach in which the strata are filled with convenience samples rather than random samples.

Question 19

Purposive Sampling (or Judgment or Judgmental Sampling)

Answer 19

The research selects participants because they will be particularly informative about the topic under investigation.

Question 20

Criterion Sampling

Answer 20

Participants are selected on the basis of identified characteristics that will provide needed information

Question 21

Typical Case Sampling (Model Instance Sampling)

Answer 21

Participants are selected on the basis of being “typical” or “representative”

Question 22

Extreme Case Sampling

Answer 22

Participants are selected on the basis of being “unique” or an “outlier”

Question 23

Maximum Variation Sampling (Maximum Heterogeneity Sampling)

Answer 23

Participants are selected to represent both ends of a continuum under investigation

Question 24

Snowball Sampling (Network Sampling)

Answer 24

One begins with a few participants, and these participants nominate other participants, and these recommend still other participants. This creates an obvious lack of independence among the participants.

Question 25

Critical Case Sampling

Answer 25

Participants are chosen on the basis of a dramatic example of the phenomenon being studied

Question 26

Purposeful Random Sampling

Answer 26

A random sample of small size from the population is used as a purposeful sample

Question 27

Concurrent Sample

Answer 27

Two independent samples are taken concurrently: a random sample for the quantitative part of the study, and a purposeful sample for the qualitative part

Question 28

Multilevel Sampling

Answer 28

Samples are taken that are representative of different levels of aggregation that comprise the overall population (e.g., district, school, and classroom). This is sometimes called nested, because groups are contained within one another.

Question 29

Stratified Purposeful Sampling

Answer 29

Type I: First collecting a stratified probability sample, and then taking a purposeful subsample from this original stratified sample
Type II: First collecting a purposeful sample, and then stratifying this sample on a variable of interest, and finally taking a subset of the original sample using the stratification variable as part of the selection process

Question 30

volunteer sample

Answer 30

Volunteers differ in systematic ways from non-volunteers: They: are better educated, have higher SES, are more intelligent, have greater need for approval, are more sociable, are more unconventional, are less authoritarian, and less conforming

Question 31

Typically, in quantitative studies we look for > _____ subjects in descriptive studies, > _____ in correlational studies, and > _____ per group in experimental studies

Answer 31

50 subjects
30 in correlation studies
15 per group

Question 32

In _____________, we stop sampling when no new information is forthcoming from additional cases

Answer 32

purposeful sampling

Question 33

restriction of range

Answer 33

Lack of variability in response to quantitative items can result in the inability to detect relationship.