The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Chapter One: Chapter One: The Science of PsychologyThe Science of Psychology

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Ways to Acquire Ways to Acquire KnowledgeKnowledge• Tenacity

• Refers to the continued presentation of a particular bit of information. When we hear a statement repeated a sufficient number of times, we have a tendency to accept it as being true.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Ways to Acquire Ways to Acquire KnowledgeKnowledge• Authority

• Acceptance of knowledge from an authority; taking someone’s word for it; also depends on the credibility of the person presenting the information.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Psychological DetectivePsychological Detective• What problems can you identify with acquiring

knowledge through tenacity and authority?• You have no way of knowing if the knowledge you have

gained is true.• The inability or unwillingness of tenacity and authority to

change in the face of contradictory evidence.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Ways to Acquire Ways to Acquire KnowledgeKnowledge• Experience

• Experiencing something firsthand or directly.• Is all experience perfectly accurate?

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Ways to Acquire Ways to Acquire KnowledgeKnowledge• Reason and Logic

• Based on the premise that we can apply reason and logic to a situation in order to gain knowledge and understanding. This process is frequently called a logical syllogism.

• An example of a logical syllogism is the assumption that “beautiful people are good.”

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Ways to Acquire Ways to Acquire KnowledgeKnowledge• Science

• The key elements of the scientific approach are:• Objective measurements of the phenomenon under

consideration.• The ability to verify or confirm the measurements

made by other individuals.• Self-correction of errors and faulty reasoning.• Exercising control to rule out the influence of unwanted

factors.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Ways to Acquire Ways to Acquire Knowledge (recap)Knowledge (recap)• Tenacity• Authority• Experience• Reason and Logic• Science

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Psychological DetectivePsychological Detective• Review the methods for acquiring knowledge that we

presented. How does the scientific method avoid the problems associated with tenacity, authority, experience, and reason and logic?

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Components of the Components of the Scientific MethodScientific Method• Objectivity

• A good researcher strives to be as objective as possible.

• Psychologists select research participants in such a manner as to avoid biasing factors (such as age or sex).

• Researchers frequently make their measurements with instruments in order to be as objective as possible. We describe such measurements as being empirical because they are based on objectively quantifiable observations.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Components of the Components of the Scientific MethodScientific Method• Confirmation of Findings

• Because the procedures and measurements are objective, we should be able to repeat them and confirm the original results. Confirmation of findings is important for establishing the validity of research.

• Psychologists use the term replication to refer to a research study that is conducted in exactly the same manner as a previous study. A replication with extension generates new information at the same time it confirms previous findings.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Components of the Components of the Scientific MethodScientific Method• Self-correction

• Errors and faulty reasoning that become apparent should lead to a change in the conclusions we reach.

• If experimental evidence fails to support the predicted relations between our independent and dependent variables, we change our view about how nature operates.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Components of the Components of the Scientific MethodScientific Method• Control

• Direct manipulation of factors of major interest.• An experiment is an implementation of control by

manipulating the factor(s) that is the central focus of research.

• Control of unwanted factors• Potentially influential and undesirable factors (other

than the factor of major interest) are not allowed to change.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Components of the Components of the Scientific Method (recap)Scientific Method (recap)• Objectivity• Confirmation of findings• Self-correction• Control

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Psychological The Psychological ExperimentExperiment• Experiment

• An attempt to determine the cause-and-effect relations that exist in nature.

• Researchers are interested in determining those factors that result in or cause predictable events.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Psychological The Psychological ExperimentExperiment• In its most basic form the psychological experiment

consists of three related factors:• The independent variable• The dependent variable• Extraneous variables

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Psychological The Psychological ExperimentExperiment• Independent Variable (IV)

• The factor that is the major focus of the research and that the researcher directly manipulates.

• Manipulation of the IV corresponds to one use of the term control.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Psychological The Psychological ExperimentExperiment• The IV is:• Independent

• Can be directly manipulated by the investigator.• Variable

• Is able to assume two or more values (levels).• The causal part of the relation we seek to establish.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Psychological The Psychological ExperimentExperiment• Dependent Variable (DV)

• Consists of the the recorded information or results of the experiment.

• Is the effect half of the cause-and-effect relation we are examining.

• Changes in DV scores will depend on the manipulation of the IV.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Psychological The Psychological ExperimentExperiment• Extraneous Variables

• Are there factors, other than the independent variable, that can influence the dependent variable and change the results of your experiment?

• When an extraneous variable is present, we have no way of knowing whether the extraneous variable or the IV caused the effect we observe.

• Attention to extraneous variables represents another use of the term control.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Psychological The Psychological ExperimentExperiment• Establishing Cause-and-Effect Relations

• Only when we manipulate an independent variable and control potential extraneous variables are we able to infer a cause-and-effect relation.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Psychological The Psychological Experiment (recap)Experiment (recap)• Independent variable• Dependent variable• Extraneous variables• Establishing cause-and-effect relations

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process• Finding a Problem

• Each research project begins as a problem or a question for which we are seeking an answer.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process• Reviewing the Literature

• Finding out what research studies already exist in an area.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process• Theoretical Considerations

• A theory is a formal statement of the relation among the relevant variables in a particular research area. All good theories:

• Attempt to organize a given body of scientific data.• Point the way to new research.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process The HypothesisThe Hypothesis• Attempts to state specific IV-DV relations within a

selected portion of a larger, more comprehensive research area or theory.

• The research or experimental hypothesis is the predicted outcome of a research project.

• The research hypothesis states a testable prediction about the relations between the independent and dependent variables in your experiment.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process• Research Design

• A general plan for conducting your research.• Your research design specifies:

• How you will select your participants and assign them to groups.

• The types of extraneous variable control(s) you will use.

• How you will gather your data.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process• Conducting the Experiment

• The next step is to actually conduct the experiment (gather the data).

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process Data Analysis and Statistical DecisionsData Analysis and Statistical Decisions• Once the data has been gathered, it has to be analyzed.• Based on the results of the data analysis, we will decide

whether manipulating the IV had a significant effect on the DV.

• If manipulation of the IV had a statistically significant effect on the DV, and if the experiment was well-designed, we can infer that the IV manipulation was the cause of the DV effect we recorded.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process Decisions in Terms of Past Research and Decisions in Terms of Past Research and TheoryTheory• Statistical results must be interpreted in light of past

research and theory.• Was our experimental hypothesis supported?• Do our results agree with past research?• How do our results fit into the current theoretical

structure in this research area?• If our results do not fit perfectly, what changes need to

be made in our interpretation or existing theory to accommodate them?

• Does lack of support for our hypothesis disconfirm the theory?

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process Preparing the Research ReportPreparing the Research Report

• A research report is the way we share our results with the scientific community.

• A research report is prepared according to the format prescribed by the American Psychological Association (APA).

• APA format allows researchers to know exactly what to include in their papers and readers to know exactly where to look for specific experimental details, procedures, and results.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process• Sharing Your Results: Presentation and Publication

• The two most popular ways to share results are:• Present an oral paper or a poster at a psychological

convention, and/or• Publish an article in a professional journal.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

The Research ProcessThe Research Process• Finding a New Problem

• The more deeply you immerse yourself in a research area, the more questions and problems you will find to research.

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Why is the Research Why is the Research Methods Course Methods Course Important?Important?• It Assists You in Other Classes

• The more completely you understand research methodology, the better you will be able to master the material in your other classes.

• Conducting an Original Research Project• The research methods course often includes or is followed

by conducting an original project. This provides an excellent opportunity to present or publish your findings.

• Conducting a Research Project After Graduation• You might have to conduct research as a condition of

future employment (even if you’re not particularly interested in research at this point in time).

The Psychologist as Detective, 4e by Smith/Davis © 2007 Pearson Education

Why is the Research Why is the Research Methods Course Methods Course Important?Important?• Getting into Graduate School

• Psychology graduate admissions committees view a course in research methods or experimental psychology very positively.

• Having presented or published a report is also rated very highly by graduate school admissions committees.

• Becoming a Knowledgeable Consumer of Research• If you understand the research on which a variety of claims

are based, then you are in a position to make a more educated decision concerning such knowledge claims.