Chapter 1 (con’t) Psychology & Science
Mar 26, 2015
Chapter 1 (con’t)Psychology & Science
Research Method
Tool for answering questions 3 Types
Survey Case study Experiment
Research Method #1 - Surveys
Asking many individuals to answer a fixed set of questions Advantages
Obtain information from a large group quickly Compare answers from different groups (age, SES, culture)
Disadvantages Responses may be influenced by
phrasing of the question who asks the question
People may not answer truthfully
Research Method #2 - Case Study
In-depth analysis of a person’s thoughts, feelings, beliefs, or behaviors
Advantage Provides rich, descriptive detail
Disadvantage Bias & error related to testimonials
Testimonial
Statement in support of a particular viewpoint based on detailed observations of an individual’s personal experience
Problems with Testimonials Biased personal beliefs Self-fulfilling prophecy Placebos & placebo effects
Statistical Procedure - Correlation
A relationship/association between 2 or more events Advantage
Study variables as they are Disadvantage
Can’t determine cause-and-effect relationships
Correlation Coefficient
Numerical measure of the strength of the relationship 2 Areas to consider
Size ranges from 0 to +/- 1.00
Sign (positive or negative) indicates the direction of association
5 Types of Correlation Coefficients
Perfect Positive Correlation (+1.00) Increase in 1 event is matched by an equal increase in a 2nd
event Positive Correlation
As one event tends to increase, the 2nd event tends to increase Zero Correlation
No relationship between the occurrence of one event and the occurrence of a 2nd event
Perfect Negative Correlation (-1.00) Increase in 1 event is matched by an equal decrease in a 2nd
event Negative Correlation
As one event tends to increase, the 2nd event tends to decrease
Research Method #3 - Experiment
Following rules and guidelines that minimize the possibility of error and bias in order to identify cause-and-effect relationships
Advantages Can identify cause-and-effect relationships Minimizes error and bias
Conducting Experiments - 7 Rules to Reduce Error & Bias
Rule 1: Ask a question in the form of a hypothesis Hypothesis = educated guess
Rule 2: Identify the Independent Variable (IV) & Dependent Variable (DV) IV = Treatment DV = Outcome measure
Source: Long Beach, CA. United School District, 1993-1994 versus 1994-1995.
Rule 3: Choose subjects who are representative of the population by using random selection Random selection
each subject has an equal chance of being selected to participate
Conducting Experiments - 7 Rules to Reduce Error & Bias
Rule 4: Randomly assign subjects to experimental and control groups Experimental group
receives the treatment Control group
does not receive the treatment
Conducting Experiments - 7 Rules to Reduce Error & Bias
Rule 5: Manipulate the IV by administering the treatment to the experimental group Double blind procedure
neither the experimenter nor the subject knows which group is receiving the treatment
Conducting Experiments - 7 Rules to Reduce Error & Bias
Rule 6: Measure effect of the IV on the DV
Rule 7: Analyze results using statistical procedures Statistical procedures are used to determine whether observed
differences in the DV are due to the IV or to chance
Conducting Experiments - 7 Rules to Reduce Error & Bias
Placebos & Placebo Effects
Placebo Treatment that resembles medical therapy, but has no medical
effects Example
taking a sugar pill Placebo Effect
Change in the patient’s illness that is attributable to an imagined treatment
Example taking a sugar pill alleviates patients’ symptoms
Research Method #4: Naturalistic Observation
Allows you to view psychological phenomenon in its naturally occurring environment
Researcher does not have to attempt to control or change the situation
Problem: Own biases may influence what is seen!
Research Concerns
Code of Ethics Developed by APA Specifies the researchers’ responsibilities & participants’ rights
Deception Must satisfy the APA’s code of ethics Sometimes used to control for subjects’ expectations
Debriefing Explaining the purpose & method of the experiment Answering any questions or discussing problems subjects may
have with the study