1. An EXPERIMENT allows researchers to control or manipulate the situation being studied THE EXPERIMENT

2. IMPORTANT! ALL experiments MUST meet the American Psychological Association’s (APA) code of ethics ALL experiments MUST meet the American Psychological Association’s (APA) code of ethics There must be INFORMED CONSENT from participants There must be INFORMED CONSENT from participants All risks must be presented and no harm can be done to the subject All risks must be presented and no harm can be done to the subject Animals must be treated humanely Animals must be treated humanely

3. EXPERIMENTAL VARIABLES INDEPENDENT VARIABLE: can be manipulated by the experimenter INDEPENDENT VARIABLE: can be manipulated by the experimenter DEPENDENT VARIABLE: experimenters predict this will be affected by the manipulations of the independent variable DEPENDENT VARIABLE: experimenters predict this will be affected by the manipulations of the independent variable (“DEPENDS” on the independent variable) (“DEPENDS” on the independent variable) EVERY experiment has at least one of each! EVERY experiment has at least one of each!

4. Identify the Independent & Dependent Variable A scientist wants to know if a warm glass of milk before bed results in peaceful sleep A scientist wants to know if a warm glass of milk before bed results in peaceful sleep Researchers want to test the effects of cigarette smoking on lung cancer Researchers want to test the effects of cigarette smoking on lung cancer Molly wants to find out if exercising will have any affect on her dreams Molly wants to find out if exercising will have any affect on her dreams

5. EXPERIMENTAL REQUIREMENTS To eliminate “chance” in an experiment, a CONTROL CONDITION is needed To eliminate “chance” in an experiment, a CONTROL CONDITION is needed Control subjects are not treated the same as those being experimented upon. Control subjects are not treated the same as those being experimented upon. HOW IS THIS DONE? 1) RANDOM ASSIGNMENT : subjects are randomly assigned to control and experimental groups (to avoid bias) 2) PLACEBO : an inactive substance used as a control in an experiment (not always used)

6. DOES VIAGRA WORK FOR WOMEN? Placebos are essential to determine whether people taking a new drug improve because of the drug – OR because of their expectations about it. In one study, 41% of women taking Viagra said their sex lives had improved. Impressive!...but 43% taking a placebo pill said their sex lives also improved.

7. GETTING ACCURATE RESULTS SINGLE-BLIND STUDY: subjects do NOT know whether they are in an experimental or control group SINGLE-BLIND STUDY: subjects do NOT know whether they are in an experimental or control group To eliminate any other bias, we might run a… DOUBLE-BLIND STUDY: Neither the experimenter nor the subjects know who is in each group. DOUBLE-BLIND STUDY: Neither the experimenter nor the subjects know who is in each group.

8. Shortcomings of Experimentation Not always representative of population Not always representative of population Most volunteers = college students Participants are aware of their actions Most volunteers = college students Participants are aware of their actionsSOLUTIONS? FIELD RESEARCH: the careful study of behavior conducted in a natural setting outside the lab. FIELD RESEARCH: the careful study of behavior conducted in a natural setting outside the lab. Example: Prejudice in offices and schools