Dr. William G. HuittValdosta State University

Introduction to Psychology

Last revised: May 2005

Why Study Psychology

• Learn more about yourself

• Investigate psychology as a major

• Learn more about others

• Need a social science course

• Learn more about how others influence you

• Learn more about how you influence others

Ways to Validate Truth or Reality

• Intuition

• Religious scripture and interpretation

• Philosophy and logical reasoning

• Science and the scientific method

• Social and/or cultural consensus

• Personal experience

Scientific Method

– The orderly, systematic process researchers follow as they

• identify a research issue, question or problem , • design a study to investigate the issue, • collect and analyze data, • draw conclusions, and • communicate their findings

– The database that is developed using the scientific method

Purpose for Using Scientific Method

• Description

• Explanation

• Prediction

Understanding

• Influence or Control

Database• Facts & Concepts

• Theories

• Principles

• Laws

Critieria for Using Scientific Method

• Knowledge must be grounded in experience

• Knowledge must be grounded in a paradigm or exemplar

• Any hypothesis must be potentially falsifiable

Psychology

Definition– The scientific study of behavior and mental

processes (or mind and behavior) especially as it relates to individual human beings

• Related areas of study– Philosophy– Other sciences

• Biology• Sociology• Anthropology• History

– Literature and the arts– Religion

Science or common sense?

http://www.kcmetro.cc.mo.us/longview/ctac/psychology/Commonsense2.htm

Psychology

• Goals of Psychology– Description

• First step in understanding most behaviors or mental processes

• Describes the behavior or mental process of interest as accurately and completely as possible

• Tells what occurred

– Prediction• When researchers can specify the conditions under

which a behavior or event is likely to occur

Psychology

• Goals of Psychology (continued)– Explanation

• Requires an understanding of the conditions under which a given behavior or mental process occurs

• Enables researchers to state the causes of the behavior or mental process they are studying

• Tells why a given event or behavior occurred

– Influence or Control• When researchers know how to apply a principle or

change a condition to prevent unwanted occurrences or to bring about desired outcomes

Psychology

• Two types of research that help psychologists accomplish these goals– Basic research

• Research conducted to advance knowledge rather than for its practical application

– Example: studying the nature of memory

– Applied research• Research conducted to solve practical problems

– Example: exploring methods to improve memory

Psychology

• Critical thinking– The process of objectively evaluating claims,

propositions, or conclusions to determine whether they follow logically from the evidence presented

– Critical thinking is the disciplined mental activity of evaluating arguments or propositions and making judgments that can guide the development of beliefs and taking action.  

– The foundation of the scientific method

Psychology

• Creative thinking– Producing new ideas or thoughts. Imaginative

thinking that is aimed at producing outcomes that involve synthesis of ideas or lateral thinking; thinking that is more synthetical than analytical, sometimes referred to as divergent thinking.

Descriptive Research Methods

• Descriptive research methods– Research methods that yield descriptions of

behavior rather than causal explanations• Naturalistic observation• Laboratory observation• Case studies• Surveys• Interviews• Questionnaires

Research Methods

• Description

• Explanation

• Prediction

Understanding

• Influence or Control

Type of Study• Descriptive

• Correlational

• Experimental

• Theoretical

Population vs Sample

• Population– The entire group that is of interest to researchers

and to which they wish to generalize their findings; the group from which a sample is selected

• Sample– The portion of any population that is selected for

study and from which generalizations are made about the larger population

Selecting A Sample

• Representative sample– A sample of participants selected from the larger

population in such a way that important subgroups within the population are included in the sample in the same proportions as they are found in the larger population

– Biased sample• A sample that does not adequately reflect the larger

population

– Random sample• A sample selected where everyone in the population has

an equal chance of being included in the sample

Descriptive Research Methods

• Naturalistic observation

• Laboratory observation

• Case study

• Survey

• Interviews

• Questionnaires

Correlational Method

• Correlational method– A research method used to establish the

degree of relationship (correlation) between two characteristics, events, or behaviors

– For use when it is impossible to manipulate variables of interest

Correlational Method

• Correlational coefficient– A numerical value that indicates the strength and

direction of the relationship between two variables– Coefficients range from +1.00 (a perfect positive

correlation) to –1.00 (a perfect negative correlation)– The further the correlation coefficient is from zero,

the stronger the coefficient– The sign determines the direction of the relationship

• (+) Positive – as one variable increases, the other must also increase

• (-) Negative – as one variable increases, the other must decrease

Experimental Method

• Experimental method– The research method in which researchers:

• randomly assign participants to a control group or an experimental group

• control all conditions other than one or more independent variables, which are then manipulated

• determine their effect on some behavioral measure, the dependent variable in the experiment

– Variable• Any condition or factor that can be manipulated, controlled,

or measured

Experimental Method

• Independent variable– In an experiment, the factor or condition that the

researcher manipulates in order to determine its effect on another behavior or condition known as the dependent variable

– Sometimes referred to as the treatment

• Dependent variable– The variable that is measured at the end of an

experiment and is presumed to vary as a result of manipulations of the independent variable

Experimental Method

• Experimental group– In an experiment, the group that is exposed to the

independent variable, or the treatment• Control group

– In an experiment, a group that is similar to the experimental group and is exposed to the same experimental environment but is not exposed to the independent variable; used for purposes of comparison

• Hypothesis– A prediction about the relationship between two or

more variables

Potential Problems

• Confounding variables– Any factors or conditions other than the independent

variable that could cause observed changes in the dependent variable

• The placebo effect• Selection bias• Experimenter bias

– Double-blind technique

Limitations of the experimental method

• The more control a researcher exercises over the setting, the more unnatural and contrived the research setting becomes

• Unethical or not possible in many areas of interest– For instance, researchers could not addict humans

to tobacco to establish that smoking tobacco causes cancer

– Scientists could not testify that smoking tobacco causes cancer – only that smoking tobacco is highly correlated with cancer