ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Chapter 2: Psychological Research

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. The Scientific Method systematicallyThe approach used by psychologists to systematically acquire knowledge and understanding about behavior and other phenomena of interest

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Scientific Method: The Process Conduct Research Identify a Question of Interest Develop an explanation

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Scientific Method: Developing Explanations Theories –Broad explanations and predictions concerning phenomena of interest Hypothesis –A prediction stated in a way that allows it to be tested

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Scientific Method: Conducting Research Research –Systematic inquiry aimed at the discovery of new knowledge Operationalization –Process of translating a hypothesis into specific, testable procedures that can be measured and observed

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Conducting Psychological Research

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Research Methods Archival research –Use of existing data in order to test a hypothesis Naturalistic research –Observation of naturally occurring behavior without intervention

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Research Methods Survey research –A sample of people is asked a series of questions about their behavior, thoughts, and attitudes in order to represent a larger population

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Research Methods Case study –An in-depth, intensive investigation of an individual or small group of people –Drawback? It is impossible to make valid generalizations to a larger population

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Research Methods Correlational research –The relationship between two sets of variables is examined to determine whether they are associated or “correlated” –Correlation does not mean “causation” –Ranges from +1 to -1

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Research Methods Correlational research

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Correlational Research

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Research Methods Variables –Behaviors, events, or other characteristics that can change, or vary in some way

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Research Methods Experiment –The relationship between two (or more) variables is investigated by deliberately producing a change in one variable in a situation and observing the effects of that change on other aspects of the situation

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Experimental Research Control Group: A group that receives no treatment Experimental manipulation: The change that an experimenter deliberately produces in a situation Experimental group: Any group receiving a treatment Treatment: The manipulation implemented by the experimenter

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Experimental Research Independent Variable –The variable that is manipulated by an experimenter Dependent Variable –The variable that is measured and is expected to change as a result of changes caused by the experimenter’s manipulation of the independent variable

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Experimental Research: Final Step Random assignment to condition –Participants are assigned to different experimental groups or “conditions” on the basis of chance and chance alone

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc.

Experimental Research: Final Step Significant outcome –Meaningful results that make it possible for researchers to feel confident that they have confirmed their hypotheses Replication –Repetition of findings using other procedures in other setting

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Moving Beyond the Study Latane’ and Darley’s experiment Group size can cause changes in the degree of helping behavior

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc.

Critical Research Issues Ethics Protection of participants from physical and mental harm The right of participants to privacy regarding their behavior The assurance that participation in research is completely voluntary The necessity of informing participants about the nature of procedures before their participation in the experiment Informed consent Deception and debriefing

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Critical Research Issues Choosing participants who represent the scope of human behavior Should animals be used in research?

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Threats to Experiment Validity Experimental bias –Factors that distort how the independent variable affects the dependent variable in an experiment Experimenter expectations Participant expectations

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Threats to Experiment Validity Placebo –A false treatment, such as a pill, “drug”, or other substance, without any significant chemical properties or active ingredient

ﴀﴀ © 2008 The McGraw-Hill Companies, Inc. Becoming an Informed Consumer of Psychology What was the purpose of the research? How well was the study conducted? Are the results presented fairly?