Evaluating Theories in Scientific Research

Evaluating Theories

• A good theory should be parsimonious, meaning it should have fewer statements.
• Theories with mathematical equations or computer problems are generally more precise and better than those with loose verbal statements.
• A theory should be testable, as a theory that cannot be tested can never be disproved.
• A theory must fit the data it explains, although goodness of fit is not a sufficient criterion for accepting a theory.

Independent, Dependent, and Intervening Variables

• Independent variables are manipulated by the experimenter, such as hours of deprivation.
• Dependent variables are observed by the experimenter, such as the rate of bar pressing.
• Intervening variables are abstract concepts that link independent variables to dependent variables, such as thirst.

Theories and Hypotheses

• Theories cannot be tested directly, but scientists perform experiments to test hypotheses derived from a theory.
• A hypothesis is a specific, testable statement that can be evaluated from observable data, such as the frequency of accidents involving left turns.
• A generalization is a broader statement that cannot be tested directly, such as "older drivers are unsafe at any speed".

The Scientific Method

• The scientific method is based on the assumption that events have causes and that we can discover those causes through controlled observation.
• Science is a repeatable, self-correcting undertaking that seeks to understand phenomena on the basis of empirical observation.
• The scientific method has several advantages, including being empirical and self-correcting.

Empirical and Self-Correcting

• Empirical means that experience rather than faith is the source of knowledge.
• Empirical observations make science a self-correcting endeavor, as they offer procedures for establishing the superiority of one belief over another.

Theories in Psychology

• A theory can be defined as a set of related statements that explains a variety of occurrences.
• Theories in psychology perform two major functions: providing a framework for organizing data and generating predictions for situations in which no data have been obtained.
• Theories are devised to organize concepts and facts into a coherent pattern and to predict additional observations.

This quiz assesses your understanding of the key principles for evaluating theories in scientific research, including parsimony, precision, testability, and fit with data. Learn how to critically analyze and compare theories in various fields of study.