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Research Methods in Psychology

Chapter 1The Scientific Method

And so much more

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Psychology…

The science of behavior

Two connotations of science

1) Content (what we know)2) Process (an activity that includes) a) gathering data

b) noting relationshipsc) offering explanations

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IS Red Wine good for you, even though it doesn’t have much resveratrol? http://www.podcastdirectory.com/podshows/2256667 forward to 23.30

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Scientific methods…1) Specifying conditions

2) Systematic observation

3) Explanations of behavior

Methodology…Scientific techniques used to

collect and evaluate data (the facts and figures gathered in research studies).

Methods include:

Everything in Methods section of paperSubjects, Apparatus and Procedures

And ‘methods’ used in Results sectiondata transforms, statistical techniques, p values

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Commonsense psychology…The kind of everyday, nonscientific

data gathering that shapes our expectations, beliefs and directs our behavior toward others (Heider, 1958).Summer internship in

Paris…“absence make the heart grow fonder” or “out of sight, out of

mind”

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1) Source of information

2) Inferential strategies

Constraints:

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Nonscientific sources of data…

although seemingly trustworthy (e.g., friends, family, people we admire, books or even news reports), are not always very good sources for obtaining valid information.

Is there any source that is?

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What about this guy?

God doesn’t roll dice with the Universe

E = MC2

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Any truthiness to superstitions…If you believe that the full moon

triggers “lunacy” you might notice and remember abnormal behaviors more and ignore the many more instances of no abnormal behavior during this lunar event.

However, we can’t avoid all superstitions, myths and urban legends…

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Apparently, there is some scientific evidence to support the belief that Friday the 13th is unlucky!

Any truth to superstitions…

Scanlon, Luben, Scanlon, & Singleton, 1993

Scanlon et al. 1993…

Retrospecitive study comparingGroup A: Fri 13 to Group B: Fri 6th

Measuresvehicles on motorwaysshoppers in supermaketshospital admissions due to car accidents

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Scanlon et al. 1993…

ResultsFewer vehicles on highway on Fri 13Number of shoppers were the sameIncreased hospital admission due to

Auto accident on Fri 13

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Exercise… Pick someone in the room who you perceive to be different from you.

Nonscientific inference…

Together, create a list of the actual differences between you and your partner. (5 min.)Next, create a list of the commonalities between you and your partner. (5 min.)

Tally the number of differences and the number of similarities.

Result of exercise…

You’re suppose to learn that you have more in common than you initially thought…

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As commonsense psychologists, we are trait theorists.

Nonscientific inference…

Perceiving others in terms of their traits can lead to overestimations of the likelihood that they will act in certain ways in a wide variety of situations.

Inferential biases are believed to be the brain’s way of coping with an immense amount of information.

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Alfred North Whitehead traced the development of science in his book Science and the Modern World (1925). He postulated that “faith” in an organized universe is essential to science.

Scientific mentality…

Research psychologists share the belief that there are specifiable reasons for the way people behave.

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Observable or experienced data are preferable to commonsense data, but does not guarantee that correct conclusions will be reached.

Empirical data…

Modern scientists propose general principles – laws or theories - to explain observable data.

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Laws are applicable to all situations.

General principles…

Theories pull together groups of scientific facts into an organizing scheme or set of rules.

Science progresses only through progressively better theories. ( Popper, 1963)

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Collection and interpretation of data should be systematic, objective and rational.

Good thinking…

Avoid letting private beliefs or expectations influence observations or conclusions.

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Pre-conceptual science…

“…assessing a situation in terms of preconceived fixed notions while ignoring or rejecting any contrary signs. (Tuchman, 1984, p. 7).”

M&H call it woodenheaded thinking

Comics: Non Sequitur

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Pre-conceptual science…

“…assessing a situation in terms of preconceived fixed notions while ignoring or rejecting any contrary signs. (Tuchman, 1984, p. 7).”

M&H call it woodenheaded thinking

Comics: Non Sequitur

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Pre-conceptual science…

“…assessing a situation in terms of preconceived fixed notions while ignoring or rejecting any contrary signs. (Tuchman, 1984, p. 7).”

M&H call it woodenheaded thinking

Comics: Non Sequitur

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Principle of Parsimony, a.k.a. Occam’s Razor “entities should not be multiplied without necessity”

Good thinking…

Avoid unnecessary assumptions to support a hypothesis. When two explanations are equally defensible, the simplest explanation is preferred until conflicting data rules it out.

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Science involves a constant re-evaluation of concepts and explanations.

Self-correction…

Falsification – challenging existing explanations and theories by testing hypotheses that follow logically from them.

modus tollens (procedure of falsification) – it only takes one case of a contrary instance to prove a statement false.

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Scientists publish their results in scientific journals and report findings at professional conferences.

Publicizing results…

Reporting scientific findings is very important to avoid unnecessary duplication of experimental work.

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Replicating experimental work ensures that a result can be reproduced, which sometimes does not happen and may even reveal scientific misconduct.

Replication…

As we shall see in the documentary: The Dark Secret of Hendrik Schön

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Observation – systematic recording of events.

The Tools of Psychological Science

Measurement – assigning numerical value to events and objects according to conventional rules or standards.

Experimentation – is a process to show that certain events are predictable under certain, specifiable conditions.

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Can only be done if a prediction is testable. Two minimum requirements

1. procedures for manipulating the setting

2. the predicted outcome must be observable

Drug A increases…dreaming spatial mappinganxiety etc.

Experimentation

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Antecedent conditions – circumstances that come before an event or behavior.

Scientific Explanations in Psychological Science

Treatment conditions – antecedent conditions that we create in an experiment.

The psychology experiment – a controlled procedure in which at least two different treatment conditions are applied to the subjects.

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1) If the experiment has adequate control AND

Establishing cause and effect…

4) This is always stated in terms of the probability or likelihood that the treatment caused the behavioral difference between subjects.

2) If the two treatments result in differences in the behavioral measure, THEN3) We can infer a cause and effect relationship (antecedent outcome)

The Colbert Nation:Truthiness

38A statistically sound scientific concept!