Psychologists Analyze Data Scientifically Behavior must be measurableBehavior must be measurable –detected by direct observation or other measuring devices Methods and data must be objectiveMethods and data must be objective –no opinions or bias Scientists must be able to communicate the results of their experiment to othersScientists must be able to communicate the results of their experiment to others –Meetings, journals

Guidelines cont. Procedures must be repeatableProcedures must be repeatable –Other scientists can do the same procedure or experiment Must use an organized and systematic approach in gathering dataMust use an organized and systematic approach in gathering data

METHODS NATURAL OBSERVATION: – –Observing and recording the behavior of organisms in their natural environment. – –ADVANTAGE: description of the way organisms behave in their surroundings – –DISADVANTAGE: no information on how or why the behavior occurs

METHODS cont. DIRECTED OBSERVATION: – –Involves observing behavior under controlled conditions in an experimental or a laboratory setting – –ADVANTAGE: Allows for control of events and behaviors – –DISADVANTAGE: Taking an organism from its natural environment may change its behavior

METHODS cont. CASE-STUDY METHOD: – –Study an individual’s background forces that influence their behavior (family background, home life, neighborhood, school, etc.) – –ADVANTAGE: Information true of all can be gained by studying one individual – –DISADVANTAGE: Information comes from family, teachers and friends of individual being studied (biased?) Info. may be misleading

METHODS cont. INTERVIEWS: – –One-on-one questioning – –ADVANTAGE: Develop rapport, relaxed atmosphere, questions in advance/flexibility – –DISADVANTAGE: getting rid of the personal prejudices of the interviewer, difficulty in expressing the results of an interview in exact terms

METHODS cont. QUESTIONNAIRE: – –ADVANTAGES: Gather facts about individuals or opinions Answers can be treated statistically

METHODS cont. TESTS – –I.Q. – –Aptitude (A.S.V.A.B.) – –Achievement (A.C.T., S.A.T., M.A.P.) – –ADVANTAGES: more objective data than interviews and questionnaires Results can be expressed in statistical terms Scores can be compared with scores for large groups – –DISADVANTAGES: Results do not give full and final answers to individual problems

METHODS cont. EXPERIMENTAL METHOD: – –Most often used by psychologists – –Begins with a hypothesis: tentative assumption or an educated guess that is often based on some previous research (“if-then”) – –Ex. If _______________ pays attention, takes notes, and doesn’t whine; then she/he will get a better grade.

EXPERIMENTAL METHOD cont. Hypothesis: states a relationship between 2 or more variablesHypothesis: states a relationship between 2 or more variables –(any condition or behavior that can change in amount or in quality) –Independent variables: Controlled and manipulated by the experimenter to determine how it affects the dependent variableControlled and manipulated by the experimenter to determine how it affects the dependent variable –Dependent variables: Changes in response to the independent variableChanges in response to the independent variable

EXPERIMENTAL METHOD cont. Subjects in an experimentSubjects in an experiment –Organism, human or animal, participating in an experiment Responses are the dependent variableResponses are the dependent variable Random: each individual has an equal chance of being selected (random selection)Random: each individual has an equal chance of being selected (random selection) Experimental group:Experimental group: –The group in which the condition under study is present Control group:Control group: –The group in which the condition is not present (random assignment)

EXPERIMENTAL METHOD cont. Three advantages to using animalsThree advantages to using animals 1.Behavior of animals can be controlled in a manner not possible with humans (cages, etc.) 2.Short life spans –Study several generations 3.Some experiments can be performed on animals but not on humans

EXPERIMENTAL METHOD cont. American Psychological Association (APA): sets guidelines for the treatment of subjectsAmerican Psychological Association (APA): sets guidelines for the treatment of subjects –Keep personal information confidential, protect from harm, inform of the nature of the experiment

EXPERIMENTAL METHOD cont. THEORY:THEORY: – – A general principle, based on information, to explain what has been learned.

EXPERIMENTAL METHOD cont. PROBLEMS WITH THE EXPERIMENTAL METHOD 1. 1.If a subject knows he/she is in an experiment, they may change their ordinary behavior 2. 2.Selection of individuals to participate in studies 3. 3.Generalizing from results – –Students/public rats/people 4. 4.Opinions of the experimenter may affect the results – –Selection and treatment of subjects 5. 5.Protection of the privacy of subjects - -Names and individual results must be kept confidential

longitudinal studies A psychologist studies the same group of people at regular intervals over a period of years to determine whether their behavior and/or feelings have changed and if so, how.

cross-sectional studies. In this study, psychologists organize individuals into groups based on age.  Then, these groups are randomly sampled, and the members of each group are surveyed, tested, or observed simultaneously.

ASSIGNMENT Develop two hypothesis of your own. Label the variables, explain what your experimental group would do, and what your control group would do.Develop two hypothesis of your own. Label the variables, explain what your experimental group would do, and what your control group would do.