Copyright © 2010 Allyn & Bacon This multimedia product and its contents are protected under copyright law. The following are prohibited by law: any public performance or display, including transmission of any image over a network; preparation of any derivative work, including the extraction, in whole or in part, of any image; any rental, lease, or lending of the program. PowerPoint Presentations for Psychology The Science of Behavior Seventh Edition Neil R. Carlson, Harold Miller, C. Donald Heth, John W. Donahoe, and G. Neil Martin Prepared by Linda Fayard Mississippi Gulf Coast Community College

Copyright © 2010 Allyn & Bacon Chapter 2 The Ways and Means of Psychology

Copyright © 2010 Allyn & Bacon The Ways and Means of Psychology 1. The Scientific Method in Psychology 2. Ethics 3. Understanding Research Results

Copyright © 2010 Allyn & Bacon The Scientific Method in Psychology Scientific Method:  Set of procedural research rules scientists should follow Three major types of research:  Naturalistic or clinical observation  Correlation study  Experiment

Copyright © 2010 Allyn & Bacon The Scientific Method in Psychology The five steps in an experiment:  Identifying the problem  Designing an experiment  Performing the experiment  Examining the data  Communicating the results

Copyright © 2010 Allyn & Bacon Identifying the Problem: Getting an Idea for Research What question do you want to study?  Go to the library and read what other people have found  Make your own observations  Talk to other researchers  Psyclit © or PsycINFO © are good places to start your search for new research ideas

Copyright © 2010 Allyn & Bacon Identifying the Problem: Getting an Idea for Research Research questions are translated into testable hypotheses  A hypothesis is a statement of what you think should happen in your experiment  A theory is a set of statements designed to explain a set of results and is more elaborate than a hypothesis

Copyright © 2010 Allyn & Bacon Identifying the Problem: Getting an Idea for Research Naturalistic observations  Observing animals in their natural environment  Remain in the background Clinical observations  In the form of case studies Survey studies  Asking people questions

Copyright © 2010 Allyn & Bacon Designing an Experiment  Independent variables  Dependent variables  Experimental group  Control group  Operational definitions  Confounding of Variables

Copyright © 2010 Allyn & Bacon Figure 2.1: Basic Design of the Driving and Cell Phone Distraction Experiment

Copyright © 2010 Allyn & Bacon Figure 2.2: Independent and Dependent Variables

Copyright © 2010 Allyn & Bacon Confounding of Variables  We must control our independent variable  Sometimes an unexpected variable is also introduced during an experiment; this is called a confound

Copyright © 2010 Allyn & Bacon Figure 2.5: A Schematic Representation of the Flawed Predator Experiment

Copyright © 2010 Allyn & Bacon Figure 2.6: Counterbalancing in the Predator Experiment  In the previous experiment, the order of the stimuli was always the same, and confounded the results  Counterbalancing the order of the stimuli prevents confounding

Copyright © 2010 Allyn & Bacon Performing an Experiment Reliability of Measurements  Are the measurements repeatable?  Subjectivity affects reliability  Inter-rater reliability

Copyright © 2010 Allyn & Bacon Performing an Experiment Selecting the participants  How do you select the participants?  Random assignment reduces confounding

Copyright © 2010 Allyn & Bacon Figure 2.7: A Possible Problem with the Anger and Concentration Experiment

Copyright © 2010 Allyn & Bacon Performing an Experiment Expectancy effects  Participant expectations  Single blind experiments  Experimenter expectations  Double blind experiments

Copyright © 2010 Allyn & Bacon Correlational vs. Experimental Studies  Correlational studies  cannot infer causation  can only state that there is a relationship between the variables of interest  may be due to a third unknown variable  Experimental studies  can infer a causal relationship between the variables of interest

Copyright © 2010 Allyn & Bacon Performing a Correlational Study

Copyright © 2010 Allyn & Bacon Reporting and Generalizing a Study  What does your experiment mean in the real world? (e.g. Haddock & Zanna, 1997) Generalization:  Can you apply your results to the population from which you took your sample?

Copyright © 2010 Allyn & Bacon Ethics  Research with Human Participants  Research with Animals

Copyright © 2010 Allyn & Bacon Research with Human Participants  Requires compliance with the following principles:  Minimize risk and maximize benefits  Informed consent  Deception generally unacceptable  Private lives generally off limits  Confidentiality  Vulnerable populations  Institutional Review Board (IRB)  Ensures compliance with ethics principles

Copyright © 2010 Allyn & Bacon Research with Animals  As animals cannot give informed consent, researchers must respond to the following questions:  Is the research important and worth doing?  Have we minimized harm to the animals?  Are the animals getting the best possible care?  Are the animals being treated humanely?

Copyright © 2010 Allyn & Bacon Understanding Research Results  Descriptive Statistics: What Are the Results?  Inferential Statistics: Distinguishing Chance from Significance

Copyright © 2010 Allyn & Bacon Descriptive Statistics: What are the Results? Descriptive statistics  Numeric descriptors  Central tendency (mean, median, and mode)  Dispersion (range, variance, and standard deviation)  Measurement of relations  Correlation coefficients range from 0 to 1  Can be positive or negative; indicates direction or relationship

Copyright © 2010 Allyn & Bacon Descriptive Statistics: What are the Results Graphing the data in a scatterplot  Linear relationships  Nonlinear relationships

Copyright © 2010 Allyn & Bacon Figure 2.9: A Scatterplot of the Test Scores and Average Grades of 10 Students

Copyright © 2010 Allyn & Bacon Figure 2.10: Scatterplots of Variables Having Several Different Levels of Correlation

Copyright © 2010 Allyn & Bacon Inferential Statistics: Distinguishing Chance from Significance  Calculates the probability that results are due to chance  Statistical significance is determined by statistical analyses performed on the data and found when an observed relation or difference between two variables is not due to chance

Copyright © 2010 Allyn & Bacon Figure 2.11: A Frequency Distribution