Psychological Research Methods Excavating Human Behaviors

Intuition We make decisions based off “gut instinct” much of the time Unfortunately, that “gut instinct” (our intuition) is highly limited…except with multiple choice questions! This intuition limits our ability to think critically!

Critical Thinking When we think critically, we do not blindly accept arguments & conclusions! Examines assumptions Discerns hidden values Evaluates evidence VS

Hindsight Bias The tendency to believe, after learning the outcome, that you knew it all along.

Overconfidence We tend to think we know more than we do. “There is no reason for anyone to have a computer in their home.” ~ Ken Olson, President of Digital Equipment Company, 1977 “Heavier-than-air flying machines are impossible.” ~ Lord Kelvin, British mathematician, 1895 “Man will never reach the Moon, regardless of all future scientific advances.” ~ Lee DeForest, inventor, 1957 “We regard the agreement as symbolic of the desire of our two peoples never to go to war with one another again. I believe it is peace for our time.” ~ British Prime Minister Neville Chamberlin, after signing the Munich Agreement with Adolf Hitler in 1938 (Oops)

Psychology is a SCIENCE RESEARCH METHODS Remember: Psychology is a SCIENCE It all starts with a THEORY

Scientific Method Observe some aspect of the universe. Invent a theory that is consistent with what you have observed. Use the theory to make predictions. Test those predictions by experiments or further observations. Modify the theory in the light of your results. Go to step 3.

Scientific Method OBSERVE: THEORIZE (PREDICT): I observe that when guys take “selfies”, girls are less interested in them. THEORIZE (PREDICT): I theorize that the more “selfies” a guy takes, the less dates he will go on.

Hypothesis Have operational definitions. Be replicable. A tentative theory that has not yet been tested – but can be IF __________, THEN __________. Have operational definitions. Be replicable.

The SCIENTIFIC METHOD putting our theories to the test.  The key to having a hypothesis is having what scientists call operational definitions. An operational definition clearly identifies how variables will be measured and makes replication possible. I observe that when guys take “selfies”, girls are less interested in them. If a male takes a picture of himself either in the mirror or with his camera facing him (“selfie), he will go on less dates than a male counterpart who does not take these sorts of pictures.

I observe that when students sleep in class, their grades drop. The SCIENTIFIC METHOD putting our theories to the test.  The key to having a hypothesis is having what scientists call operational definitions. An operational definition clearly identifies how variables will be measured and makes replication possible. I observe that when students sleep in class, their grades drop.

Our methods for researching fall into 3 categories: TESTING OUR HYPOTHESIS Our methods for researching fall into 3 categories:   DESCRIPTIVE simply describes the event CORRELATIONAL describes the relationship between variables and allows one to predict behavior EXPERIMENTAL attempt to actually show a cause/effect relationship

Descriptive Research Any research that observes and records. What is going on in this picture? We cannot say exactly, but we can describe what we see. Thus we have….. Descriptive Research Any research that observes and records. Does not talk about relationships, it just describes.

Types of Descriptive Research The Case Study The Survey Naturalistic Observation

The Case Study Where one person (or situation) is observed in depth. What are the strengths and weaknesses of using a tragedy like the Columbine School Shootings as a case study?

Naturalistic Observation Observing and recording behavior in natural environment. No control- just an observer. What are the benefits and detriments of Naturalistic Observation?

The Survey Method Descriptive/Correlational Used in both descriptional and correlational research. Use Interview, mail, phone, internet etc… The Good- cheap, anonymous, diverse population, and easy to get random sampling (a sampling that represents your population you want to study).

Survey Method: The Bad Low Response Rate People Lie or just misinterpret themselves. Wording Effects How accurate would a survey be about the frequency of diarrhea?

Random Sampling

DESCRIPTIVE / CORRELATIONAL RESEARCH Components of Survey Population: all the individuals you are interested in knowing something about i.e. the entire student body of Ardrey Kell Sample: the individuals you actually question. i.e. Two homerooms from each grade level, selected at random Sampling should always be taken randomly from the population so that it is representative meaning each individual in the population had an equal chance of being selected.

Why do we sample? One reason is the False Consensus Effect: the tendency to overestimate the extent to which others share our beliefs and behaviors.

Correlational Research Detects relationships between variables. Does NOT say that one variable causes another. There is a positive correlation between ice cream and murder rates. Does that mean that ice cream causes murder?

Correlation does NOT equal Causation RESEARCH METHODS Correlation does NOT equal Causation Just because there is a relationship between two variables does not mean one caused the other

Correlation does NOT equal Causation RESEARCH METHODS Correlation does NOT equal Causation Correlational Studies can help researchers predict behavior. Think of it this way… You and your brother are related (correlation) You did NOT cause your brother (causation)

positive correlation negative correlation indicates a direct relationship (as A , B OR as A , B ) Ex: The more sit-ups you do, the more fat you will lose. Ex: The fewer sit-ups you do, the less fat you will lose. -1.0 -.5 0 +.5 +1.0 negative correlation indicates an inverse relationship (as A , B ) Ex. The more ice cream you eat, the less fat you will lose.

Correlation Coefficients A number that measures the strength of a relationship. Range is from -1 to +1 The relationship gets weaker the closer you get to zero.

Illusory Correlation Does kindergarten lead to crime? The perception of a relationship where none exists Does kindergarten lead to crime? Are the French really overly rude?

Experimental Research Explores cause and effect relationships. Constipation Eating too many bananas causes

Steps in Designing an Experiment Hypothesis Pick Population: Random Selection then Random Assignment. Operationalize the Variables Identify Independent and Dependent Variables. Look for Extraneous Variables Type of Experiment: Blind, Double Blind etc.. Gather Data Analyze Results

Experimental Vocabulary Independent Variable: factor that is manipulated Dependent Variable: factor that is measured Extraneous Variables: factors that effect DV, that are not IV. Experimental Group: Group exposed to IV Control Group: Group not exposed to IV Placebo: inert substance that is in place of IV in Control Group

POPULATION Population SAMPLE Experimental Group Control Group ASSIGNMENT

Experiments Want to Avoid Confounding (Lurking) Variables EXPERIMENTAL RESEARCH Experiments Want to Avoid Confounding (Lurking) Variables Confounding Variable(s): refers to a “hidden” or uncontrolled aspect of an experiment that can distort the results of an experiment. Example: Having the experimental group tested in a different room than the control group would be a confounding variable. Why?

Analyze Results Use measures of central tendency (mean, median and mode). Use measures of variation (range and standard deviation).

Statistics Recording the results from our studies. Must use a common language so we all know what we are talking about.

Descriptive Statistics Just describes sets of data. You might create a frequency distribution. Frequency polygons or histograms.

Normal Distribution In a normal distribution, the mean, median and mode are all the same.

Distributions Outliers skew distributions. If group has one high score, the curve has a positive skew (contains more low scores) If a group has a low outlier, the curve has a negative skew (contains more high scores)

A Skewed Distribution Are the results positively or negatively skewed?

Other measures of variability Range: distance from highest to lowest scores. Standard Deviation: the variance of scores around the mean. The higher the variance or SD, the more spread out the distribution is. Do scientists want a big or small SD? Shaq and Kobe may both score 30 ppg (same mean). But their SDs are very different.

Inferential Statistics The purpose is to discover whether the finding can be applied to the larger population from which the sample was collected. T-tests, ANOVA or MANOVA P-value= .05 for statistical significance. 5% likely the results are due to chance.