Kathy’s perception that she was outside of herself； unable to stop her flight toward death。 Health
psychologists and those who work in the area of sports psychology might try to identify signs of stress and
clues in earlier behaviors that could have signaled an impending breakdown。 Psychologists who
emphasize the biological basis of behavior might consider the role of brain and hormonal factors in her
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sudden； abnormal reaction。 Are there any circumstances under which you might quit as Kathy O。 did？
We may never pletely understand what motivated Kathy’s behavior； but psychology provides the
tools—research methods—and the scaffolding—theories about the causes of behavior—for exploring basic
questions about who we are and why we think； feel； and act as we do。 Psychologists are challenged to make
sense of cases such as this one that violate ordinary conceptions about human nature。 Their motivation is
not only intellectual curiosity； but also a desire to discover how to help people in ways that might prevent
such tragedies in the future。
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CHAPTER 2
Research Methods in Psychology
LEARNING OBJECTIVES
On pletion of this chapter； students should be able to：
1。 Explain why the empirical study of psychology is important
2。 Describe the theory behind and the benefits of the scientific method
3。 Understand the importance of the scientific method to psychology
4。 Elaborate on the role of control and bias in psychological research
5。 Understand the importance of determinism to psychology in particular and science in general
6。 Explain how psychologists attempt to eliminate alternative explanations through the use of control
procedures
7。 Understand the concept of correlation and its use in psychology
8。 Explain why correlation does not imply causation
9。 Appreciate how the approach taken by psychologists can be applied to aspects of students’ lives
outside the classroom
CHAPTER OUTLINE
I。 The Context of Discovery
A。 The goal of this chapter is to improve students’ critical thinking skills by teaching them how to ask
the right questions and how to evaluate answers about causes； consequences； and correlates of
psychological phenomena。 Ultimately； this chapter should make your students wiser； more skeptical
consumers of psychological information specifically and all information generally。
1。 The initial phase of research is observation； during which beliefs； information；
and general knowledge suggest a new way of thinking about a phenomenon
2。 Some research questions originate from direct observation； while others stem
from “great unanswered questions” that have been passed down through
history
3。 A theory is an organized set of concepts that explains a phenomenon or set of
phenomena
4。 Determinism rests at the core of psychology。 Determinism is the belief that all
events； whether physical； mental； or behavioral； are the result of； or determined
by； specific causal factors。 Because of determinism； all behavior and mental
processes must follow lawful patterns。 Psychologists attempt to reveal these
lawful patterns in psychological principles。
5。 A hypothesis is a tentative； testable prediction about the relationship between
causes and consequences； or about how two or more variables are related。
Research psychologists test hypotheses。
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CHAPTER 2： RESEARCH METHODS IN PSYCHOLOGY
6。 The scientific method demands that psychological researchers have an open；
critical； skeptical mind。 This open…mindedness makes conclusions
provisional； subject to modifications by subsequent findings； and makes
researchers open to new and controversial ideas。
7。 Within experimental psychology； when evidence collected through quality
research conflicts with the opinions or ideas of experts； the evidence； or data；
wins
8。 Public verifiability is fundamental to psychology。 Secrecy is forbidden； and
psychologists must have the opportunity to inspect； criticize； replicate； or
disprove the data and methods of other researchers。
II。The Context of Justification： Safeguards for Objectivity
A。 The scientific method is a set of procedures for gathering and interpreting evidence in ways that
help ensure that psychological research generates valid； reliable conclusions by minimizing sources
of error
B。 Psychology is considered a science to the extent that it follows the scientific method
C。 Observer bias is an error due to the personal motives and expectations of the viewer。 Personal
biases of observers act as filters through which some things are noticed as relevant and significant；
while others are ignored as irrelevant and unimportant。
D。 The Remedy for Observer Bias： Standardization
1。 Standardization means using uniform procedures in all phases of the research
process。 All participants should experience exactly the same procedure； and
other researchers should be able to replicate the procedure exactly。
2。 An operational definition standardizes the meaning of an event or procedure
within an experiment。 It is a specific definition of what is meant by a concept
such as “self…esteem。” An operational definition may state that participants
that score above a certain number on a self…esteem measure are considered
“high；” while those that score below that number are considered “low。” All
variables in an experiment must be given an operational definition。
3。 A variable is any factor that varies in amount or kind。 Self…esteem is an example
of a variable。 Participants’ scores can vary from high to low。 There are two
types of variables。
a） A variable that is free to vary and is manipulated by the experimenter
is known as an independent variable。 It is also the predictor variable in
nonexperimental （e。g。 correlational） research。
b） A variable whose values are the result of changes in independent
variables is known as a dependent variable。 It is also the variable that is
predicted in nonexperimental research。
c） The experimental method—used to overe causal ambiguity—
manipulates an independent variable and then looks for an effect on a
dependent variable。
4。 Alternative Explanations are simply other ways of explaining the results of an
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PSYCHOLOGY AND LIFE
experiment。 The more alternative explanations that exist without refutation；
the less confident a researcher can be that his or her predicted explanation or
hypothesis is the correct one。
a） Confounding variables are extraneous influences not intended by the
research to be a part of an experiment； but that may unwittingly affect
experimental results。 Because confounding variables are not
accounted or controlled for； researchers cannot be certain whether
their experimental manipulation or a confounding variable is
responsible for experimental results。 Two types of confounds apply to
almost all experiments： Expectancy and Placebo Effects。
（i） Expectancy effects occur when a researcher subtly
municates to the participants the results that he or she
expects to find。 Participants may then behave in the desired
manner。
（ii） Placebo effects occur when participants’ beliefs about the
efficacy of a procedure lead to improvement in the participant。
Participants can be given chemically inert pills； and； if they
believe that the pills will make them improve； participants
often do improve； due simply to the placebo effect。 A
ponent of the placebo effect is the belief that a
manipulation will lead to improvement。 This belief does not
need to be grounded in reality。 In many studies； about a third
of participants are found to be positive placebo responders。
E。 Experimental Methods in Psychology
1。 Control procedures are methods that attempt to hold constant all variables and
conditions other than those related to the hypothesis under investigation
a） A double…blind control refers to a procedure in which both the
participant and the experimental assistant administering a treatment
are blind to； or unaware of； the experimental condition to which the
participant is assigned
b） A placebo control is an experimental condition in which participants
believe that they are receiving a treatment that may be effective； but in
which they are actually receiving a treatment that is known not to be
effective。 By paring the placebo control group with the group of
participants that received the actual treatment； researchers can
determine how much change in the participants is due to their beliefs
（placebo effect） and how much is due to the treatment itself。
2。 Research designs： Properly designed experiments are another way of ensuring
that alternative explanations are kept to a minimum。 By determining which
alternative explanations are likely to be serious petitors to the explanation
directly under investigation； researchers can incorporate conditions that test
these alternative explanations in their research。
3。 Random assignment is one of the most important aspects of research design。 It
helps ensure that the participants in each condition are as similar to each
other as possible； because each participant has the same chance of being in
each condition。
4。 Because researchers would like to be able to generalize their findings from
their sample； the participants in their study； to the larger population from
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which the sample was drawn； the sample should be representative of the
population； or a representative sample
5。 In between…subjects designs； participants are randomly assigned to one
experimental condition or one control condition。 There may be more than one
experimental condition； in which participants are exposed to different
treatments； and there may be more than one control condition； in which
participants are not exposed to those treatments。 This allows researchers to
account for alternative explanations。 However； each participant is only in one
condition。
6。 In within…subjects designs； each participant serves as his or her own control； as
they are assigned to a