@ 2012 wadsworth, cengage learning chapter 3 developing the hypothesis @ 2012 wadsworth, cengage...

@ 2012 Wadsworth, Cengage Learning

Chapter 3Chapter 3

Developing the Developing the HypothesisHypothesis



Topics1. Making Our Hypotheses Concrete2. Making Our Hypotheses Logical3. Creating Testable Research Hypotheses and the

Problem of Measurement4. Overview5. Ideas Come From Everywhere6. Intuition and Revelation7. The Scientist’s Guide to Having an Idea8. Tools for Library Research


Making Our Hypotheses Making Our Hypotheses ConcreteConcrete


Making Our Hypotheses Concrete

• Dilemma– How can we scientifically evaluate our private

ideas about the world?

• One answer– Define private ideas in terms of specific behaviors

that anyone can witness


Making Our Hypotheses Concrete (cont’d.)

• Operational definition– Representations of psychological events in the

physical world – Defines events in terms of the operations required

to measure them– Takes a general concept and places it within a

given context


Figure 3.1 From any one global construct, there are several possible operational definitions, depending on the questions asked and the type of population studied


Making Our Hypotheses Concrete (cont’d.)

• Construct validity– Asks whether the procedure that we are using is

an adequate definition of the construct that we are measuring

– Example: ask whether a particular measure of depression allows us to make valid inferences about the construct of depression


Making Our Hypotheses Logical


Making Our Hypotheses Logical

• The “I wonder what will happen if” hypothesis and inductive reasoning– Generalizing from a specific instance to a more

general idea– Example: observing a chimpanzee using sign

language with a person, and concluding that chimpanzees can communicate with humans

– Danger: overlooking unobserved factors that may be responsible for the effects that we observe


Figure 3.2 Inductive and deductive relationships between observation and theory


Making Our Hypotheses Logical (cont’d.)

• The “I expect this would happen if” hypothesis and deductive reasoning– Takes the form of an if-then statement– If my idea about the world is correct, then this

cause should produce the following effect– Example: “If it is true that schizophrenia is

determined genetically, then we should find a greater incidence of the disorder between twins than between strangers”



• Four steps that characterize strong inference– Devise alternative hypotheses– Devise a crucial experiment with alternative

possible outcomes– Carry out the experiment– Return to step 1 with further refinements of the

supported hypothesis



• Platt sees strong inference as: – A method for rapid progress in science – A procedure at the heart of every scientist’s

thinking:Obviously it should be applied as much to one’s own thinking as to others’. It consists of asking in your own mind, on hearing any scientific explanation or theory put forward, “But sir, what experiment could disprove your hypothesis?”; or on hearing a scientific experiment described, “But sir, what hypothesis does your experiment disprove?” (Platt, 1964, p. 352)


Creating Testable Research Hypotheses and the

Problem of Measurement


Creating Testable Research Hypotheses

• Transition from a general idea to a specific research hypothesis requires careful thought

• It is not always easy to ask a question that can be answered scientifically

• Measurement: one aspect of the transition to a testable research hypothesis

• For a method of measurement to pass the test of reliability, the measurements must be consistent


Creating Testable Research Hypotheses (cont’d.)

• Test–retest reliability: correlation between the scores on each of the testing occasions

• For a method of measurement to pass the test of validity, it must be accurate

• To be valid, a measurement must reflect the true score within certain limits

• Choose methods of measurement that are both accurate (valid) and consistent (reliable)


Overview


Figure 3.3 Steps required before experimentation


Ideas Come from Everywhere


Figure 3.4 Steps involved in forming a research hypothesis


Intuition and Revelation


Intuition and Revelation

• We do not know much about the workings of our brains

• We do not know where spontaneous ideas come from

• We can examine cases in which spontaneous ideas have influenced the course of science


Intuition and Revelation (cont’d.)

• When asked how he came upon ideas and solved problems, Einstein replied:

The words or the language, as they are written or spoken, do not seem to play any role in my mechanism of thought. . . . The above mentioned elements are, in any case, of visual and some of muscular type. Conventional words or other signs have to be sought for laboriously only in a secondary stage. (Koestler, 1964, p. 171)


Intuition and Revelation (cont’d.)

• Simple dream of a snake biting its own tail – Led to the idea of a ring of carbon atoms

• Spontaneity of insights – Preceded by years of intensive work

• Insights had to be translated into workings of science


The Scientist’s Guide to Having an Idea


The Scientist’s Guide to Having an Idea

• Graham Wallas (1926) described the scientific process in four stages:– Preparation: person becomes interested in a

problem– Incubation: close to meditating on a topic but not

thinking about it– Illumination: solution begins to emerge into

consciousness– Verification: when you test your idea


Tools for Library Research


Tools for Library Research

• Journals: major outlet in which scientists describe their research

• Peer review: experts in the author’s particular field read the paper and gave suggestions before the article was published

• Computer databases: useful for their ability to search for categories of research that normally might not be indexed


Box 3.1


Tools for Library Research (cont’d.)

• PubMed– Performs the same function as PsycINFO but for

medical journals– Assesses a database called MEDLINE, which is part

of the U.S. National Library of Medicine– Accessed through a variety of sources, including

the PubMed website: http://www.ncbi.nlm.nih.gov/PubMed


Box 3.2


Tools for Library Research (cont’d.)

• Science Citation Index (SCI) and the Social Science Citation Index (SSCI) – List articles published in either the sciences or the

social sciences– Found in an online site entitled Web of Science

• Internet– No guarantee that the information you receive is

always correct or unbiased– Go to sites maintained by major institutions


Summary

• Creating an operational definition is one way researchers clarify their ideas

• Scientists obtain ideas for research from a variety of sources

• Wallas suggested four stages: preparation, incubation, illumination, and verification

• Reference libraries contain important tools for helping us find articles

@ 2012 wadsworth, cengage learning chapter 3 developing the hypothesis @ 2012 wadsworth, cengage...

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