Chapter 2: Developing and Evaluating Theories of Behavior

Chapter 2: Developing and Evaluating Theories of Behavior

Why conduct research?

• To develop proposed explanations for phenomena

• To evaluate and test developed theories

What is a theory?

• A plausible or scientifically acceptable, well-substantiated explanation of some aspect of the natural world

  • Explains | logically | something in natural world

  • Based on reasonable assumptions from what we already know

  • The assumptions it is based off of must be based off of well-researched well-established facts

  • | Successfully accounts for known phenomena and has correctly predicted the outcomes of new observations |

• Physics & chemistry most successful in rigorous theory-building. Harder for psychology, sociology, etc since they involve highly complex interacting systems

Characteristics of a Good Theory

• Ability to account for data

  • Explain data

• Testable

  • Not psychoanalytic theory

• Parsimonious

  • Get rid of assumptions

• Explanatory relevance

  • Logical links between things

• Predictability

What is a hypothesis?

• A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation. Scientific hypotheses must be posed in a form that allows them to be rejected

• Educated guesses, more limited in scope, They do not involve a complex set of assumptions and logical relationships as theories usually do.

• They have to make sense

• Hypothesis ≠ prediction

  • I hypothesize that my new therapy for posttraumatic stress disorder will be more effective than the standard one.” That’s a prediction, not a hypothesis. It states the expected result but does not explain why that result is expected

• Ex: Darwin’s theory of evolution

  • This theory proposes three principles: variation, natural selection, and reproduction of the selected characteristics

  • offer a powerful explanation for how species change over time, the emergence of new species, and the extinction of others, in organisms ranging from viruses to humans. This broad scope qualifies Darwin’s proposal as a theory

  • Based on Darwin’s theory, one could hypothesize

  • Whereas Darwin’s theory has broad scope, the hypothesis just presented applies to a specific question about a particular characteristic of a male of a single species. The hypothesis is testable in that it leads to specific predictions that can be supported or refuted by the proposed experimental observations

What is a law?

• An empirically verified, quantitative relationship between two or more variables

• | Theory that has a lot of support (data) |

  • Ex: the matching law (think pigeons)

• Another way to think about it... well-established relationships that must be explained by a theory

What is a model?

• Specific implementation of a more general theoretical view

  • Ex.: Rescorla-Wagner model of classical conditioning

• Represents an application of a theory

• Computer models

Mechanistic Explanations vs. Functional Explanations

• Mechanistic: describes the components and how it works works

• Functional: describes an attribute of something in terms of its function and why an attribute or system exists

• You can usually figure out functional explanation if you know the mechanistic explanation, BUT you CANNOT figure out the mechanistic from only the functional.

Quantitative or qualitative?

• Quantitative

  • Specific numerical inputs & outputs

  • Basically... defines things numerical

• Qualitative 

  • Any theory that does NOT define variables numerically

Level of Description

• Descriptive theories

  • Describes how variables are related

• Analogical theories

  • Explains relationships of variables through analogy 

  • (think Lorenz’s fixed action pattern and chicken example)

• Fundamental theories

  • Explain specific areas of research, but do not need analogy to do so

  • Rarer than the other two

Theory Domain

• Another way of saying “scope” of a theory

• What situations can this theory be applied to?

  • Wider scope=wider range of situations

  • Narrower scope=fewer situations that theory could be applied to

Roles of Theories in Science

• Understanding & explaining phenomena

• Predicting behaviors

• Help with organizing and analyzing research results

  • Rely on the theory to explain the results  

• Can provide new ideas for research

Testing Theories

• Conformational Strategy

  • Don’t do it!

• Disconfirmational Strategy

• Using the Two Together

• Strong Inference

Key Terms

• Theory

  • A plausible or scientifically acceptable, well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena and predict the characteristics of as-yet-unobserved phenomena

    • Ex. Theory of Cognitive Dissonance (Festinger) – explains how people feel discomfort when their beliefs and behaviors don’t match, and predicts that they’ll try to reduce that discomfort (by changing their beliefs, attitudes, or actions).

    • explains (why/how it happens). 

• Hypothesis

  • A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation. Scientific hypotheses must be posed in a form that allows them to be rejected

    • Educated guesses, more limited in scope, They do not involve a complex set of assumptions and logical relationships as theories usually do.

• Law

  • A relationship that has been substantially verified through empirical test

    • Theory that has a lot of support (data)

    • describes (what happens)

• Model

  • Specific implementation of a general theoretical view. The term model is sometimes used as a synonym for theory

    • Represents an application of a theory

    • represents (a simplified version to understand or predict).

• mechanistic explanation

  • An explanation for a phenomenon given in terms of a mechanism that is assumed to produce it through an explicit chain of cause and effect

    • Describes the components and how it works

    • how it works (the machinery).

    • Ex. emotion fear: the amygdala activates, triggers hypothalamus, releases stress hormones, heart rate increases, muscles tense, prepared to act

• functional explanation

  • An explanation for a phenomenon given in terms of its function, that is, what it accomplishes

    • Describes an attribute of something in terms of its function and why an attribute or system exists

    • why it exists (the purpose).

    • Ex. emotion fear: helps you survive

• quantitative theory

  • A theory in which terms are expressed mathematically rather than verbally

• qualitative theory

  • A theory that defines the relationships between its variables and constants in a set of mathematical formulas

• descriptive theory

  • A theory that simply describes the relationship among variables without attempting to explain the relationship

• analogical theory

  • A theory that explains a relationship through analogy to a well-understood model.

• fundamental theory

  • A theory that seeks to model an underlying reality that produces the observed relationships among variables

• Domain

  • The range of situations to which a theory applies. Also called the scope of a theory

• confirmational strategy

  • A strategy for testing a theory that involves finding evidence that confirms the predictions made by the theory.

• disconfirmational strategy

  • A method of testing a theory that involves conducting research to provide evidence that disconfirms the predictions made by the theory

• strong inference

  • A strategy for testing a theory in which a sequence of research studies is systematically carried out to rule out alternative explanations for a phenomenon