Sampling Activity

Experimental Psychology (PSYC/CHLD 3404)

Student learning outcomes

• Distinguish between basic and applied research questions
• Distinguish between random sampling and random assignment
• Identity the population given a hypothesis
• Determine which sampling method is likely to effectively answer a research question given a hypothesis
• Identify conditions under which sampling is most important—situations under which sampling bias will distort inferences made from the data
• Distinguish between internal validity and external validity
• Determine the conditions under which sampling procedures lead to problems in the inferences one draws from research.

Part 1 Review. Instructions:Using your textbook, write brief definitions for the following concepts in your own words.

Population ___________________________________________________________________

Probability sampling This is related to random selection procedures (i.e. simple random, cluster, and stratified random sampling; contrast with convenience, haphazard, and quota sampling). Probability sampling procedures require that one is able to identify every person in the population. Once everyone is identified, then you may randomly select individuals so that each person has an equal probability of being selected. Note, this is rare because we usually are not able to identify every individual in a given population.

Random Assignment_____________________________________________________________

Simple random sampling _________________________________________________________

Cluster sampling ________________________________________________________________

Stratified random sampling ________________________________________________________

Convenience and haphazard sampling (a.k.a. non-probability sampling______________________

Basic research___________________________________________________________________

Applied research ________________________________________________________________

Internal validity__________________________________________________________________

Five components of external validity:

External validity includes one’s ability to generalize the data to different people, in different settings, and using different methodology. External validity also means that one will be able to replicate the work and that the findings apply to real life settings.

Part 2 Sampling.  Instructions:Please read each hypothesis and answer the questions that follow.For some items, students should describe their rationale in choosing the item.

1. Does job satisfaction decrease absenteeism at Walgreens?

• Identify the target population

1. Walgreens workers
2. Humans
3. Adults
4. Adolescents

• Is this a basic or an applied research question?

1. Basic
2. Applied

• Does the question seem to require an observational, survey or experimental research design?

1. Experimental
2. Survey/Correlational
3. Observational

• What sampling procedure would you recommend the researcher use?

1. Simple random sampling
2. Cluster sampling
3. Convenience sampling
4. Stratified random sampling
5. Quota sampling

Explain your answer:

• Imagine that the research question was explored using surveys and a correlational research Essentially, employees were asked how satisfied they are with their jobs and how often they had been absent during the previous year of work. Imagine haphazard sampling procedures were used. Would this have a significant impact on the conclusions drawn from the research?

1. Yes
2. No

Explain your answer:

2. Do ergonomic[1] working conditions increase productivity?

• Identify the target population

1. Office workers
2. Humans
3. Working Adults
4. Adolescents

• Is this a basic or an applied research question?

1. Basic
2. Applied

• Does the question seem to require an observational, survey or experimental research design?

1. Experimental
2. Survey/Correlational
3. Observational

• What sampling procedure would you recommend the researchers use?

1. Simple random sampling
2. Cluster sampling
3. Convenience sampling
4. Stratified random sampling
5. Quota sampling

Explain your answer:

• Imagine that the research question was explored using anexperimental design. People in similar jobs (e.g., office jobs) were randomly assigned toan ergonomic working condition or no ergonomic working condition. Those in the ergonomic working condition were given new equipment(experimental condition) or were not (control condition). After four weeks the productivity in the experimental and control groups was compared. Those in the ergonomic working condition had higher productivity than those in the control condition.Now imagine that haphazard sampling procedures were used. Would this present a problem for external or internal validity?

1. Yes
2. No

Explain your answer:

3. Do more men or women cut in line? Does age matter?

• Identify the target population

1. Men
2. Women
3. Humans
4. Adults

• Is this a basic or an applied research question?

1. Basic
2. Applied

• Does the question seem to require an observational, survey or experimental research design?

1. Experimental
2. Survey/Correlational
3. Observational

• What sampling procedure would you recommend the researchers use?

1. Simple random sampling
2. Cluster sampling
3. Convenience sampling
4. Stratified random sampling
5. Quota sampling

Explain your answer

• Imagine that the research question was explored using anobservational research Further, imagine that to collect the data, one went to the ticket booth where tickets to an extremely popular performance were being sold (e.g., one of the coolest musicians ever). Would you be confident about the types of conclusions drawn from the data?

1. I would be confident about the conclusions drawn
2. I would not be confident about the conclusions drawn

Explain your answer:

4. Do natural serotonin supplements alleviate symptoms of depression as well as pharmaceutical (serotonin reuptake inhibitor) therapies?

• Identify the target population

1. People with depression
2. People without depression
3. Humans
4. Adults

• Is this a basic or an applied research question?

1. Basic
2. Applied

• Does the question seem to require an observational, survey or experimental research design?

1. Experimental
2. Survey/Correlational
3. Observational

• What sampling procedure would you recommend the researchers use?

1. Simple random sampling
2. Cluster sampling
3. Convenience sampling
4. Stratified random sampling
5. Quota sampling

Explain your answer:

• Imagine that the research question was explored using a survey/correlational research People with depression were asked what kind of therapy they were using and then asked to report the length and severity of their symptoms before and after treatment. Would haphazard sampling procedures have a significant impact the conclusions drawn from the research?

1. yes
2. no

Explain your answer:

• Imagine that the research question was explored using an experimental research People with depression were randomly assigned to a natural or pharmaceutical therapy condition and their symptoms were then closely monitored. Imagine further that participants in the pharmaceutical group showed marked and significant improvements in symptoms compared to those in the natural therapy group. Would haphazard sampling procedures have a significant impact on the conclusion drawn from the research?

1. Yes
2. No

Explain your answer:

Part 3Discussion Questions.

Answer the following questions alone then discuss your answers with your team.

1. Are sampling procedures more important in applied or basic research contexts? Explain your answer.

2. Are sampling procedures more important in experimental or non-experimental (quasi-experimental, observational, correlational) contexts? Explain.

[1] Ergonomics is the applied science of equipment design. A wrist rest for computer stations is an example of an ergonomic design.

Last Updated on March 8, 2019