Deck 6: Selecting a Sample

Question 1

In sampling a phenomenon to investigate in a research study, quantitative researchers need to

A) select individuals for study who are familiar with the phenomenon.
B) study the entire population that represents instances of the phenomenon.
C) apply replication logic.
D) systematically select instances of the phenomenon for the sample.

Answer 1

systematically select instances of the phenomenon for the sample.

Question 2

Unlike quantitative researchers, qualitative researchers select their samples to

A) satisfy the requirements of grounded theory.
B) test theories about the phenomenon being studied.
C) accurately represent a defined population.
D) study cases that are information-rich with respect to their research questions.

Answer 2

study cases that are information-rich with respect to their research questions.

Question 3

The most important requirement for being able to generalize the results of a quantitative research study is to

A) minimize sample attrition and missing data.
B) formulate a theory and use it to interpret the study's findings.
C) define a population in advance of data collection and sample from it.
D) use measures for which population norms are available.

Answer 3

define a population in advance of data collection and sample from it.

Question 4

All the members of a set of persons to whom a researcher wishes to generalize the results of a study are referred to as

A) the defined population.
B) the accessible population.
C) the target population.
D) the sampling distribution.

Question 5

Another term corresponding to target population in quantitative research is

A) accessible population.
B) universe.
C) defined population.
D) cohort.

Question 6

For a study to have population validity,

A) the study must employ an experimental research design.
B) the sample must be randomly selected from the defined population.
C) the study must replicate a previous study involving the same population.
D) research participants must be randomly assigned to the experimental and control groups.

Question 7

The deviation of a sample statistic from the actual parameter for the population from which the sample was randomly drawn is a measure of

A) population validity.
B) sampling error.
C) statistical significance.
D) variability.

Question 8

A researcher plans a study in a school district to compare method A and method B of teaching reading. Which of the following approaches would be most likely to ensure a representative sample?

A) Obtain permission from a cooperative principal to nominate students in his school to experience each teaching method.
B) Require all students enrolled in English literature classes to serve as research participants.
C) Use students from one school as research participants to receive method A and students from a comparable school to receive method B.
D) Define the population as all students in the district receiving reading instruction, select a random sample, and randomly assign students to methods A or B.

Question 9

Replication logic refers to

A) the conduct of replications of a study with samples from different populations to determine the stability of the findings.
B) the use of theory to determine the other types of cases to which the findings of one case study can be generalized.
C) the cross-validation of research hypotheses through repeated replications of the original study.
D) precise specification of a population so that subsequent researchers can draw equivalent samples in an effort to replicate the original study's findings.

Question 10

If a qualitative researcher is doing a theoretical replication, the next case to be studied should

A) differ from the first case in ways that allow a further test of the theory.
B) be similar to the first case.
C) yield similar results to the findings obtained from the first case.
D) be selected to test alternate interpretations of the findings from the first case.

Question 11

Population validity is achieved only if

A) the researcher limits generalizations of the study's findings to the accessible population.
B) a test effectively predicts a relevant variable within the target population.
C) the accessible population is randomly selected from the target population.
D) the accessible population is reasonably representative of the target population.

Question 12

Which of the following is an important criterion for determining whether an experiment has population validity?

A) A clear description of the target population
B) A detailed description of the sampling procedure
C) Identification and description of the sampling frame
D) all of the above

Question 13

An investigator wants to compare the reading comprehension of first-grade students who are taught reading by treatment A versus first-grade students taught reading by treatment B. He selects all first graders in Washington Elementary School (6 classes, N = 200) and places their names in a hat. The first 60 names taken from the hat are placed in treatment A, and the next 60 names are placed in treatment B. What procedure has the researcher used?

A) Simple random sampling
B) Random assignment
C) Cluster sampling
D) Stratified random sampling

Question 14

Stratified random sampling is usually a better approach than random sampling if the researcher

A) wants to avoid sampling bias.
B) is studying a target population that is highly homogeneous.
C) expects small differences between the groups being compared.
D) wants to study the performance of different subgroups within the sample.

Question 15

In doing a survey of Chicago residents' evaluation of their schools, the researcher divides the city into 9 square-block areas and randomly selects 20 areas for study. This is an example of

A) stratified random sampling.
B) cluster sampling.
C) subgroup analysis.
D) use of a large sample.

Question 16

A disadvantage of cluster sampling compared to other sampling techniques is that

A) one cannot use conventional formulas for computing statistics on the data.
B) it requires including research participants in the sample from every sampling unit.
C) this technique is more expensive than other sampling techniques.
D) it rejects randomization as a basis for sample selection.

Question 17

The main reason that most educational research involves non-probability sampling is researchers' concern for

A) convenience in obtaining the sample.
B) generalizability of the findings.
C) fairness to all research participants.
D) statistical significance.

Question 18

A researcher wants to analyze the match between state science standards and what is taught in the high school science curriculum. He selects the five most frequently-adopted high school science textbooks as his sample. This is an example of:

A) systematic sampling.
B) sampling of a phenomenon.
C) convenience sampling.
D) studying the entire population.

Question 19

The problem of attrition (loss of research participants) is best reduced by

A) the use of systematic sampling techniques.
B) the use of volunteers as research participants.
C) fostering research participants' commitment to the study and maintaining rapport with them.
D) including subgroups of research participants proportional to their numbers in the population.

Question 20

Put an L before the following research situations that require a large sample and an S before those situations in which a small sample is acceptable.

-Many uncontrolled variables are present.

A) L
B) S

Question 21

Put an L before the following research situations that require a large sample and an S before those situations in which a small sample is acceptable.

-Large relationships are anticipated between the variables to be correlated.

A) L
B) S

Question 22

Put an L before the following research situations that require a large sample and an S before those situations in which a small sample is acceptable.

-Subgroup analyses are to be performed.

A) L
B) S

Question 23

Put an L before the following research situations that require a large sample and an S before those situations in which a small sample is acceptable.

-The research participants have been closely matched on the critical variables.

A) L
B) S

Question 24

Put an L before the following research situations that require a large sample and an S before those situations in which a small sample is acceptable.

-Small differences are expected between the scores of the experimental and control groups

A) L
B) S

Question 25

A small sample is most appropriate when

A) small differences are anticipated between the experimental and control groups.
B) subgroup analyses are planned.
C) the population is highly heterogeneous on the variables being studied.
D) close matching of the comparison groups is possible.

Question 26

The first step in estimating needed sample size is to

A) determine the size of the target population.
B) determine the size of the accessible population.
C) study the findings of related research using similar variables.
D) determine the population mean and standard deviation for each variable of concern.

Question 27

Sampling techniques are more flexible in qualitative research than in quantitative research mainly because qualitative researchers
a. need only one or a few cases.
b. are interested in typical cases.
c. prefer emergent research designs.
d. have no interest in generalizing study results.

Question 28

The primary goal of purposeful sampling is to

A) enable researchers to test theories.
B) select cases that are information rich with respect to the study's purpose.
C) replicate the result of previous research.
D) select cases that are convenient for researchers to study.

Question 29

Replication logic is used in case study research primarily to

A) enable researchers to develop or test a theory.
B) generate research findings that can be generalized to a defined population.
C) duplicate the findings of previous research.
D) all of the above.

Question 30

In a study of teachers' use of power, selecting as a case a teacher who is known throughout the country as an exceptionally active opinion maker would be an example of

A) typical case sampling.
B) intensity sampling.
C) deviant case sampling.
D) convenience sampling.

Question 31

Random sampling in qualitative research is sometimes used in order to

A) ensure that the cases studied are representative.
B) establish that the sampling procedure is not biased.
C) confirm the findings of previous case studies.
D) select cases that illustrate the full range of variation in the phenomenon being studied.

Question 32

A qualitative researcher who is interested in the study of a phenomenon in depth would be well advised to

A) study a wide range of experiences for a small number of people.
B) study a narrow set of experiences for a large number of people.
C) document the naturally occurring diversity and variation of the phenomenon.
D) use stratified purposeful sampling to select the cases.

Question 33

Study of a large number of cases in a qualitative research study is particularly desirable for

A) avoiding redundancy in the information provided by different cases.
B) conducting critical case sampling.
C) understanding the range of diversity or variation in the phenomenon being studied.
D) doing a theoretical replication.

Question 34

Volunteers are likely to constitute a biased sample because they

A) have been found to differ from nonvolunteers on numerous characteristics.
B) are less responsive to experimental interventions than individuals who are required to participate.
C) are more susceptible to the Hawthorne effect than nonvolunteers.
D) tend to have more conservative attitudes than nonvolunteers.

Question 35

Comparing the characteristics of volunteers and nonvolunteers for a research study best helps a researcher to

A) increase the response rate.
B) determine how well the findings can be generalized to the population.
C) determine the best method to recruit participants.
D) obtain statistically significant findings.

Question 36

Compared to nonvolunteers for participation in a research study, volunteers tend to be

A) more introverted.
B) lower in need for achievement.
C) better educated.
D) more conforming.

Question 37

If it is necessary to use only volunteers in a research study, the best precaution is for the researcher to

A) consider whether volunteers are likely to differ from nonvolunteers on critical variables.
B) increase the sample size.
C) require a public commitment to participate.
D) keep the description of the study's purpose brief and matter-of-fact.

Question 38

Which of the following is an effective method for recruiting individuals to participate in a research study?

A) Make the study sound appealing.
B) Offer gifts and other benefits to prospective participants.
C) Have the request for volunteers made by a person of high status.
D) all of the above.

Question 39

In situations where volunteering is regarded by the target population as the normal thing to do, a recommended way to increase the rate of volunteering is to

A) create a situation where each individual can volunteer in private.
B) emphasize that volunteering represents a tremendous contribution to society.
C) ask each individual to make a public commitment to volunteer.
D) post a description of the study in a public place.

Question 40

A qualitative researcher who is interested in studying school teachers who moonlight in other jobs decides to select cases who have only one extra job, at which they spend no more than 10 hours a week.
a. What type of purposeful sample does the researcher appear to be seeking?
b. What is the researcher's probable rationale for limiting the study to such cases?

Question 41

What is the difference between a target population and an accessible population?

Question 42

Define sampling as this term is used in quantitative research.

Question 43

How does an educational researcher establish the population validity of his research study?

Question 44

A researcher randomly selects a sample of 100 teachers from inner-city schools in a large U.S. city. She views her sample as representative of the defined population of all inner-city school teachers in the United States. The researcher measures the teachers' attitudes toward site-based management of schools. If her study has population validity, what can she conclude from the results of the study?

Question 45

Describe one criterion that should be satisfied in order to determine that a research study has high population validity.

Question 46

Explain the difference between random sampling and random assignment in experimental research.

Question 47

State one reason why, if all other things are equal, randomly selected samples are preferable for research purposes in quantitative research.

Question 48

Name one condition under which it would be appropriate to use nonproportional stratified sampling, that is, to select an equal number of research participants from each stratum rather than selecting from each stratum the same proportion that exists in the target population.

Question 49

You wish to obtain a simple random sample of 1,000 members of the American Psychological Association to whom you will send a questionnaire about their views concerning the appropriate preparation of clinical psychologists. List the steps you would take in selecting your sample.

Question 50

Suppose that you are planning a study on the relationship between teachers' use of six verbal behaviors (specific praise, prompting, etc.) and student achievement. Your accessible population includes all fourth-, fifth-, and sixth-grade teachers in the Chicago public schools, who previously have been classified as either bilingual or English-speaking-only. Your sample will include a total of 120 teachers.
a. What sampling procedure should you use to ensure that you have an adequate sample of teachers at each grade level, including both bilingual and English-speaking-only teachers?
b. How would you carry out the sampling procedure?

Question 51

Define probability sampling, and give an example of a sampling method that involves this sampling approach.

Question 52

Explain how in sampling a phenomenon rather than individuals it might be feasible to study the entire accessible population or target population.

Question 53

Briefly describe three types of research situations that require a fairly large sample size.

Question 54

When using purposeful sampling, what does the researcher strive to accomplish in selecting the sample?

Question 55

Describe one rationale that a qualitative researcher can use to justify her selection of a particular case to study.

Question 56

Describe one type of replication that a qualitative researcher might carry out.

Question 57

Briefly name and describe three purposeful sampling strategies.

Question 58

Give one reason why a qualitative researcher might find it desirable to study more than one case in a research study.

Question 59

List three characteristics that researchers have found to differ for volunteer and non-volunteer research participants.

Question 60

State three suggestions for increasing the proportion of volunteers and thus reducing volunteer bias.

Question 61

A researcher wants to do a case study of the emotional reactions and motivational states of a child while the child is playing computer games.
a. What rationale can he use to justify generalizing about the results of the case study?
b. How could he increase the generalizability of his case study findings?

Question 62

An investigator wishes to study the oral reading performance of second-grade students in a large school district. A total of 3,172 second-grade students are enrolled in 104 classrooms in the district. The investigator wishes to obtain a total group of 100 research participants using a two-stage cluster sampling technique. Describe the steps she would take in selecting her sample.

Question 63

A researcher is studying the effects of learning a problem-solving strategy upon the mathematics achievement of sixth- grade students. He selects a sample of students in one school and randomly assigns half of them to the experimental group and half to the control group. All students will be given a pretest of mathematics achievement. The experimental group then will receive a one-hour lesson that teaches a problem-solving strategy for students to use in solving word problems in mathematics. The control group receives conventional instruction. Because he expects the problem-solving training to work best with the brighter students, the researcher divides both groups into two subgroups based on their IQ scores, using the following categories: below 90, 90-110, 111-130, and above 130. He administers a mathematics achievement posttest to all research participants two months after the treatment ends. Explain why a fairly large sample size is required for this project.

Question 64

Identify the procedures in the following research description that are likely to cause sampling bias: A researcher teaches three sections of a remedial English class for freshmen in a large state university. A colleague teaches three sections of regular freshman English. The researcher has developed a special 20-hour program to teach rules of spelling. She gives a spelling test in her sections and in her colleague's sections. She identifies 63 students from her sections and 36 from her colleague's sections who scored below 50 percent on the test. She then describes the special program to her sections and asks the 63 low scorers to take the program by attending special sessions one hour per day for four weeks. Fifty-one agree to do so. The 36 students in her colleague's sections are used as a control group and receive no special treatment. At the end of four weeks, 26 of her students have completed the spelling program, while the remainder have missed between 1 and 18 of the sessions. She administers a spelling posttest to the 26 treatment participants and the 36 control participants and compares their gains since the pretest.

Question 65

Describe a qualitative research problem for which intensity sampling would be a good purposeful sampling strategy.