UCI Education and Teaching Research Methodology Worksheet

Assignment 4
PSYED 2001/EDUC 2201: Introduction to Research Methodology
Sampling Assignment
Please type your answers below each question.
1.
What would be possible sources of sampling bias in the following sampling methods?
a.
A researcher was interested in learning in how difficult it was for junior faculty in
the tenure stream in biology departments to balance their teaching and research
responsibilities. He contacted the chairs of biology departments in a random
sample of universities, and asked each of the department chairs to choose one
junior faculty member who would be asked to complete a survey.
b.
A researcher wanted to investigate student satisfaction with library services at
the University of Pittsburgh. She arranged for her assistants to distribute surveys
to the first 200 students who entered Hillman Library on a Monday morning
between 8:30 AM and noon.
Identify the specific sampling method used in the following situations.
2.
A library science student planned a content analysis of journal articles concerned with
research ethics in the medical field. By searching a database, she obtained a list of all
relevant articles within the time period she was interested in. The search resulted in a
list of 432 articles. She then marked every fifth article on the list and analyzed those
articles.
3.
An educational researcher was interested in surveying teachers in a certain school
district to find out how often they were in contact with the parents of their students.
Based on his review of the literature he expected that elementary school teachers were
in contact with parents more frequently than high school teachers. First, from the 204
elementary school teachers in the district he randomly sampled 51 (25%). Next, from
the 68 high school teachers in the district he randomly sampled 17 (25%).
4.
A doctoral student in health and physical activity program wished to survey adolescents
to identify their most common sources of stress. She was able to obtain permission to
conduct the study in the program where she was doing her internship. Furthermore, a
faculty member in her program who had worked on a committee with the doctoral
student agreed to distribute the surveys in another program where she was supervising
participants.
1
PSYED 2001/EDUC 2201: Introduction to Research Methodology
Assignment 4
5.
A doctoral student in educational administration wanted to survey Pennsylvania school
district superintendents about their policies on teacher evaluation. He obtained a listing
of all Pennsylvania school district administrators from the State Department of
Education. Using a random number table, he selected 150 administrators and mailed his
questionnaire to them.
6.
A health educator wanted to interview school nurses in Pennsylvania elementary
schools to find out whether they provided information to students about good nutrition,
and if so, what kind of information they provided. Since it would save her considerable
travel time and expense to be able to visit several schools in the same geographic
region, she randomly sampled 10 school districts from a listing of Pennsylvania school
districts. She planned to visit every elementary school within each selected district.
2
EDUC 2201/EFOP 2001 Introduction to Research Methodology
Sampling
Lecture Note by: Shangmou Xu
Week 4 ? Lecture Note
Overview
Welcome to Week 4! In Week 3, I introduced the basic research process and you may
understand that many, if not all, research projects start with a clear stated research question(s).
While in this course, it?s not required to conduct any research or empirical analysis, I would like
you to understand that your methodology selection is based on the research goal/questions; that
is, any subsequent research procedures will ?work for? the research goal. Therefore, there is no
?right or wrong? or ?good or bad? methods. Instead, it?s all about matching methods with
research goals/questions. Please keep that in mind because we are about to learn some ?real?
research methods and it?s super helpful to think about ?research goal? all the time.
Think about any research project, what?s the next step after deciding research questions?
My answer would be: deciding population and sample. For example, my research goal is to
understand the academic motivation among US high school students and provide policy
suggestions. My research question is what factors motivate US high school students to
participate academic activities. In this case, our population would be all US high school students.
And what about sample? Well, typically we are not able to obtain information from every
individual from the population and we have to ?select? some individuals from the population and
generalize any results we get from these individuals to the whole population. These selected
individuals form my sample for this specific study and the selection process is called sampling.
Depending on the extent to which we would like to generalize the research results to the
whole population, the representativeness and the size of the sample might be different. Using the
academic motivation project as an example, our goal is to understand the high school students
across the whole country, so we want our result to be super generalizable. Therefore, our sample
should be in a high level of representativeness to ensure we can generalize the result. Of course
we may expect the sample size would be large. Another example would be a research project
about student computer lab usage among PITT-SoE students and the goal is to improve the
experience of using SoE computer lab. In this case, the population is all Pitt SoE students. We
EDUC 2201/EFOP 2001 Introduction to Research Methodology
Sampling
Lecture Note by: Shangmou Xu
still want some characteristics to be representative in our sample, like having both Mater?s and
Doctoral students, or having students from every department, but the level of representativeness
would be lower than the national representativeness study.
If our sample is not able to represent the intended population and some members of the
intended population have a lower or higher sampling probability than others, our sample is
biased, and it?s called sampling bias. Sampling bias occurs when that characteristic of a sample
differs in a systematic way from the population. Every sample is biased because no sample can
100% represent the population. However, in most cases, we are not chasing for 100%
representativeness, so we can allow sampling bias. In the exercise and assignments, we will
discuss the potential sources of sampling bias.
Because we may accept sampling bias in our research, based on the research goal, people
select different sampling method. It?s important to note that when thinking about probability
sampling methods and non-probability methods, there is no better or worse methods. Again, you
may want to match your research goal with sampling methods. Please proceed to textbook
reading and slides reading to know more details about sampling methods.
Textbook Reading
Gay, L. R., Mills, G. E., & Airasian, P. W. (2011). Educational research: Competencies for
analysis and applications (10th ed.). Upper Saddle River, NJ: Pearson.
Chapter 5, pp. 129?141
Edition 11: Chapter 5, pp. 137-149
Lecture slides
Please read through Week 4 Slides
Exercise
EDUC 2201/EFOP 2001 Introduction to Research Methodology
Sampling
Lecture Note by: Shangmou Xu
This exercise will give you a quick review and practice of identifying sampling methods and
bias. This will be helpful and midterm, so please be sure to check the item and answers.
Part 1. Please identify the specific sampling method used in the following situations:
1. A study was done to determine the age, number of times per week, and the duration
(amount of time) of residents using a local park in city A. The first house in the
neighborhood around the park was selected randomly, and then the resident of every
eighth house in the neighborhood around the park was interviewed.
Answer: Systemic sampling
2. A woman in the airport is handing out questionnaires to travelers asking them to evaluate
the airport?s service. She does not ask travelers who are hurrying through the airport with
their hands full of luggage, but instead asks all travelers who are sitting near gates and
not taking naps while they wait.
Answer: Convenience sampling
3. A teacher wants to know if her students are doing homework, so she randomly selects
rows two and five and then calls on all students in row two and all students in row five to
present the solutions to homework problems to the class.
Answer: Cluster
4. The marketing manager for an electronics store wants information on what are the most
popular brands and she thinks if varies by age of the customer. She randomly selects 100
customers from 5 different age groups and gives them questionnaires to complete.
Answer: Stratified
5. The librarian at a public library wants to determine what proportion of the library users
are children. The librarian has a tally sheet on which she marks whether books are
checked out by an adult or a child. She records this data for every fourth patron who
checks out books.
Answer: Systemic
EDUC 2201/EFOP 2001 Introduction to Research Methodology
Sampling
Lecture Note by: Shangmou Xu
6. A political party wants to know the reaction of voters to a debate between the candidates.
The day after the debate, the party?s polling staff calls 1,200 randomly selected phone
numbers. If a registered voter answers the phone or is available to come to the phone, that
registered voter is asked whom he or she intends to vote for and whether the debate
changed his or her opinion of the candidates.
Answer: Simple Random
Part 2 Please read the following sampling design and discuss: (1) whether the sample is
representative of the population and (2) the potential sources of bias of the study.
Several online textbook retailers advertise that they have lower prices than on-campus bookstores.
However, an important factor is whether the Internet retailers actually have the textbooks that students need in stock.
Students need to be able to get textbooks promptly at the beginning of the college term. If the book is not available,
then a student would not be able to get the textbook at all, or might get a delayed delivery if the book is back
ordered. A college newspaper reporter is investigating textbook availability at online retailers. He decides to
investigate one textbook for each of the following seven subjects: calculus, biology, chemistry, physics, statistics,
geology, and general engineering. He consults textbook industry sales data and selects the most popular nationally
used textbook in each of these subjects. He visits websites for a random sample of major online textbook sellers and
looks up each of these seven textbooks to see if they are available in stock for quick delivery through these retailers.
Based on his investigation, he writes an article in which he draws conclusions about the overall availability of all
college textbooks through online textbook retailers.
Is this sample representative of all college textbooks? What?s the possible courses bias in this
study?
Sample answer: The sample is not representative of the population of all college textbooks. Two
reasons why it is not representative are that he only sampled seven subjects and he only
investigated one textbook in each subject. There are several possible sources of bias in the study.
The seven subjects that he investigated are all in mathematics and the sciences; there are many
subjects in the humanities, social sciences, and other subject areas, (for example: literature, art,
history, psychology, sociology, business) that he did not investigate at all. It may be that
EDUC 2201/EFOP 2001 Introduction to Research Methodology
Sampling
Lecture Note by: Shangmou Xu
different subject areas exhibit different patterns of textbook availability, but his sample would
not detect such results.

Purchase answer to see full
attachment