Chapter 2: Thinking Critically, Scientific Method, Research Methods Psychology as a Science Chapter 2: Thinking Critically, Scientific Method, Research Methods 1

Overconfidence Effect “We don’t like their sound. Groups of guitars are on their way out.” Decca Records, in turning down a recording contract with the Beatles in 1962. Brain Games Overconfidence Trouble with Overconfidence

Perceiving order in Random events. When shown they aren't accurate, participants explain away the results. Perceiving order in random events. Random sequences often don't look random. Ex. faces on moon or jesus toast.

Critical Thinking Critical thinking does not accept arguments and conclusions blindly. It examines assumptions, discerns hidden values, evaluates evidence and assesses conclusions. Th The Amazing Randi What is he known for in the field of psychology?

Thinking Critically… Be All You Can Be! Curious Skeptical Humble explore to understand Skeptical ask why and how – don’t assume look for evidence Humble not all theories workout – test and retest new (and surprising) theories and ideas

Goals of Psychology Goal: Description of Goal

Theories, Hypotheses, Tests, Results Scientific Method Theories, Hypotheses, Tests, Results

Scientific Method Basic Procedures: Develop a hypothesis (prediction based on an educated guess – must be testable!) Perform a controlled test (operational definition – how will it be measured?) Gather objective data Analyze results (accept or reject hypothesis) Publish and replicate results (a well supported hypothesis can be replicated many times with the same results) http://gonzogastro.files.wordpress.com/2008/11/mythbusters.jpg http://www.youtube.com/watch?v=LKFanG5s01M

Scientific Method EXAMPLE: Theory – “Marijuana use has negative effects on the brain and central nervous system” Hypothesis – “Marijuana use affects short- term memory” Controlled Test – sampling of users/non-users and a series of memory exercises/tests

Descriptive, Correlational, Experimental Research Methods Descriptive, Correlational, Experimental Psychology’s Goal #3: Predict behavior

Why do we need research? Psychology is a science Overconfidence it must be based on research (empirical evidence) Overconfidence we think we know more than we do Common sense and intuition are often incorrect and provide no supporting evidence Hindsight bias false consensus effect illusory correlations 11

Terms to know: hindsight bias applied research basic research theory hypothesis dependent variable (DV) independent variable(IV) operational definitions confounding variables random sampling false consensus effect correlation coefficient scatterplots illusory correlation double-blind effect placebo effect

Case Study, Survey, Naturalistic Observation Descriptive Research Case Study, Survey, Naturalistic Observation

Descriptive Research Any research that observes and records Does NOT explain behavior, it only describes Describe what you see happening in this picture

Descriptive Research PROS CONS The subject remains in a natural, unchanged environment Used as an overview prior to scientific experiments as to what is reliable or testable Relatively low cost CONS No statistics - can’t analyze results Results cannot always be replicated Often seen as unreliable and “unscientific”

What could be the strengths and weaknesses of a case study? One person or situation is observed in depth Phineas Gage VA Tech http://womenofcaliber.wordpress.com/2009/04/16/are-you-a-%E2%80%9Cgun-free-zone%E2%80%9D/ http://img.genciencia.com http://www.sciencemuseum.org.uk What could be the strengths and weaknesses of a case study?

1. Case Study PROS CONS full, detailed picture provides a basis for future experimental study CONS some subjects are atypical cannot always make general conclusions for a larger population

How could we obtain a random sample of WBHS students for a survey? Used in both Description and Correlational research Interview via mail, phone, internet, etc. Random Sampling can increase the likelihood that the answers reflect the general population How could we obtain a random sample of WBHS students for a survey?

2. Survey PROS CONS greater access to diverse populations easy to get random samples (provide more generalized conclusions for population) anonymous cheap CONS lacks depth low response rate people can lie or misrepresent themselves wording can affect answers provided

2. Survey By a show of hands… How many approve government censorship of the media’s portrayal of sex and violence? How many are in favor of more restrictions on what is shown on TV?

2. Survey

3. Naturalistic Observation Observing and recording behavior in a natural environment Observer controls nothing http://www.und.edu/dept/anthro/web_assets/graphics/people_pics/jane_goodall.jpg

3. Naturalistic Observation PROS View subject in natural environment Unobtrusive Leads to correlational research to understand cause/effect CONS Observations can be skewed if subject is aware Only describes, does not explain why

Correlational Research Correlation and Causation, Illusory Correlations

Correlational Research Detects relationships between two variables Measured using a correlation coefficient = a statistical measure of relationship (scores range from +1.0 to -1.0) Graphed using a scatterplot DOES NOT PROVIDE CAUSE-EFFECT EXPLANATION!

EXAMPLE: Is there a correlation between watching TV and low grades in school?

Reading a Correlation Coefficient:

Scatterplots

Is there a correlation between watching TV and lower grades in school? Reading a Scatterplot Is there a correlation between watching TV and lower grades in school? This is a negative correlation - as more hours are spent watching TV, grades in school decrease

What information can we gather from this scatterplot? Reading a Scatterplot What information can we gather from this scatterplot? This is a negative correlation - as the weight of the car goes up, the mileage per gallon goes down http://www.statmethods.net/graphs/images/scatterplot1.jpg

EXAMPLE: Is there a correlation between a person’s level of income and years of education? Participant Income Years of Education #1 125,000 19 #2 100,000 20 #3 40,000 16 #4 35,000 #5 41,000 18 #6 29,000 12 #7 14 #8 24,000 #9 50,000 #10 60,000 17 http://www.nvcc.edu/home/elanthier/methods/correlation.htm

CORRELATION DOES NOT PROVE CAUSATION!!! How is this possible? There is a positive correlation between ice cream sales and murder rates. CORRELATION DOES NOT PROVE CAUSATION!!!

Illusory Correlations Perception of a relationship where none exists EX: Large dogs are more aggressive and have more instances of biting people than small dogs. If you believe there is a relationship, then you will begin to notice and recall events that support your belief (“self-serving bias”)

Correlational Research PROS Shows relationships between behaviors Statistically shows how strongly behaviors are related CONS Does not identify the cause, only reports relationships Cannot “prove” anything, only predicts possible behavior

Experimental Research Blind, Double-Blind

Experimental Research Demonstrates cause-effect relationships Blind Experiments Double-Blind Experiments

Steps in Designing an Experiment: Hypothesis Random Selection of population Identification of independent variable (manipulated) and dependent variable (measured) Operational definitions for the variables (control confounding variables) Random Assignment of population into experimental group (exposed to IV) or control group (not exposed to IV; might be exposed to placebo) Use of blind or double blind procedures Gathering of data Analysis of results Replication

Now, Let’s Practice: Hypothesis: Students who eat an oatmeal raisin cookie before class each day will have higher average scores on the semester final than students who don’t eat a cookie.

Confounding variables? Operational definitions Random assignment? Eating cookies before class each day will lead to higher average scores. YOUR GROUP MUST IDENTIFY/EXPLAIN: Random sample? IV? DV? Confounding variables? Operational definitions Random assignment? Control group? Placebo? Experimental group? Blind? Double blind? Gather data? Analysis. Generalizable? 40

Experimental Research PROS Demonstrates cause- effect relationships Empirical Evidence to support hypotheses/ theories CONS Not always feasible to perform experiments Not ethical to manipulate certain variables

Experiments Using Animals: Three advantages to using animals - Behavior of animals can be controlled in a manner not possible with humans (cages, etc.) Short life spans (Can study several generations ) Some experiments can be performed on animals but not on humans (EX: UPenn baboon experiments to study effects of whiplash on the brain; drug therapy)

Ethical Guidelines for Human Experiments: 1. Informed consent 2. Protection from harm 3. Right to withdraw 4. Confidentiality 5. Debriefing