Chapter 2 Research Methodology
In this chapter:
- How evidence is gathered and verified in psychology.
- How to interpret information that is being presented to you.
- Become an educated consumer and presenter of information.
Big questions
- How is the scientific method used in psychological research?
- What types of studies are used in psychological research?
- What are the ethics governing psychological research?
- How are data analyzed and evaluated?
How is scientific method used in psychological research?
Psychology is a science. As scientists, psychologists gain accurate
knowledge about behavior and metal processes only by observing the
world and measuring aspects of it. This approach is called empiricism.
Empirical research involves data collection and analysis and requires
carefully planned, systematic steps.
2.1 Science has three primary goals.
Learning objectives:
- Identify the tree primary goals of science.
- Describe the scientific method.
- Differentiate among theories, hypotheses, and research.
There are three primary goals of science: description, prediction, and
explanation. Psychological science uses research to describe what a
phenomenon is, predict when and where it will occur, and explain the
mechanisms behind why it occurs.
For example, people vape even though they know it can be harmful.
To understand how this behavior happens, we need to address each of the
three goals. We begin by asking. How many people really use e-cigarettes,
and are they aware of the harms? Answering this question can help us
describe the phenomenon of vaping, specially measuring the prevalence
of this unsafe behavior.
Related questions are: What are people’s beliefs about vaping? How did
they start?
Answering these questions can help us predict who’s is more likely to vape
and what causes them to vape in the first place.
What psychological processes give rise to the decision to start vaping?
Answering this question can help us understand the causal factors that
explain why people vape.
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,Knowing about the causes of vaping can help inform prevention and
treatment programs that will benefit public health.
Scientific method
Scientific evidence obtained through empirical research is considered the
best possible evidence for supporting a claim. Research involves the
careful collection, analysis, and interpretation of data. In conducting
research, scientists follow a systematic procedure called the scientific
method. This procedure begins with the observation of a phenomenon and
the question of why that phenomenon occurred.
The role of theory
The scientific research is an interaction among research, theories, and
hypotheses. A theory is an explanation or model of how a phenomenon
works. A theory is used to explain prior observations and to make
predictions about future events. A hypothesis is a specific, testable
prediction, narrower than the theory it is based on.
How can we know a theory is good?
A wide variety of testable hypothesis.
A good theory should be falsifiable (it should be possible to test hypothesis
that show the theory is wrong). Falsifiable theories help advance science
because our understanding of a phenomenon is enhanced both when
evidence supports a theory and when it does not.
Simplicity, this idea has historical roots in the writing of the fourteenth-
century English philosopher William of Occam. He proposed that when two
competing theories exist to explain the same phenomenon, the simpler of
the two theories is preferred. This theory is also known as Occam’s razor
or the law of parsimony.
2.2 The scientific method is a systematic way to test hypothesis.
The opening of this chapter considered teen vaping. Let’s say that, based
on what you have read online, you develop the theory that peer influence
causes teen e-cigarette use. To determine whether this theory is accurate,
you need to conduct research. After making an observation and
formulating a theory, you need to follow a series of seven steps that define
the scientific method.
Step 1: Pose a specific, testable research question.
Choose a specific research question that is testable using data.
Researchers can use science to answer a variety of questions that directly
test the theory.
Step 2: Educate yourself about what is already known about the theory.
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,Once you have a research question, you want to search the literature to
see what scientists have already discovered that is relevant to your theory.
Use good keywords for finding useful information.
Step 3: Form a hypothesis that will guide your studies.
Based on what you learn in your literature review, you design tests
(specific research studies) aimed at examining the theory’s predictions.
These specific, testable research predictions are your hypothesis.
Step 4: Design a study.
Designing a study refers to deciding which research method you want to
use to test your hypothesis. You can do a survey, do a naturalistic
observation or you could perform an actual experiment.
Step 5: Conduct the experiment.
Once you choose your research method, you conduct the study: recruit
participants and measure their responses. Many call this collecting or
gathering data.
All research involves variables. A variable is something in the world that
can vary, and that the researcher can manipulate (change), measure
(evaluate), or both. Researchers must define these variables precisely and
in ways that reflect the methods used to assess them. You will do so by
developing an operational definition for each of your variables. Operational
definitions are important for research. They qualify (describe) and quantify
(measure) variables so the variables can be understood objectify. Using
good operational definitions lets other researchers know precisely what
variables you used, how you manipulated them, and how you measured
them. These concrete details make it possible for other researchers to use
identical methods in their attempts to replicate your findings.
Step 6: Analyze the data.
The next step is to analyze your data. There are two main ways to analyze
data. First, you want to describe the data. Second, you will want to know
what conclusions you can draw from that data. You need to know whether
your results are meaningful or whether they happened by chance. You
accomplish data analyses by using statistics, which are described later in
this chapter.
Step 7: Report the results.
Unreported results have no value because no one can use any of the
information. Instead, scientists make their findings public to benefit
society, to support the scientific culture, and to permit other scientists to
build on their work. You can present in poster sessions, conference
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, presentations of you can publish your full report in a peer-reviewed
scientific journal, or a preprint server, where other scientists can evaluate
and comment on the work. Peer review is a process by which other
scientists with similar expertise evaluate and critique research reports, it
provides a check.
2.3 The scientific method is Cyclical.
Good research reflects the cyclical process. Once the results of a research
are in, the researchers return to the original theory to evaluate the
implications of the data. If the study used appropriate methods and data
analysis to test the hypothesis, the data either support and strengthen the
theory or suggests that the theory be modified or discarded. Then this
process starts all over again.
Replication
Replication involves repeating a study to see if the results are the same of
similar. When the results from two or more studies are the same, or at
least support the same conclusion, confidence increases in the findings.
Ideally, researchers not affiliated with those who produced the original
finding conduct replication studies. These independent replications provide
more powerful support because they rule out the possibility that some
feature of the original setting, may have contributed to the findings.
Why might a study not replicate?
Studies do not always replicate. A challenge is to understand why.
- Sometimes studies fail to replicate because the theory itself is wrong
and the original study was a false positive. A false positive occurs
when the hypothesis under investigation is false, but the study
produces a seemingly trustworthy result by change. False positives
are inevitable in science, but it is possible to keep their frequency
low.
- It is also possible that a study does not replicate because factors
that are not hypothesized to be important turn out to make a
difference.
However, for many years, scientists engaged in a number of questionable
research practices that unintentionally made their studies less likely to
replicate. The open science movement has educated researchers about
the effects of these practices, but they continue to appear in some studies.
- Small samples. Psychology researchers estimate how larger
populations of people would respond by testing smaller,
representative samples of people. A larger sample is less prone to be
skewed toward one particular town, gender, or any other factor that
might distort the results.
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