Unit 2: Research Methods Aim: To what extent did a scientific approach to psychology produce more reliable answers? Do Now: Choose an index card “Psychological findings” on cards: 1. Absence makes the heart grow fonder 2. Out of sight out of mind

The Need for Psychological Science zPsychologists, like all scientists, use the scientific method to construct theories that organize observations and imply testable hypotheses zThis research has 3 hurdles that tend to skew our logic…

1. Hindsight Bias zThe tendency to believe, after learning the outcome, that you knew it all along. Monday Morning Quarterbacking!!! After Evan Marshall (former student/teacher at Sewanhaka) was arrested for killing his neighbor by chopping her up into pieces and driving around with her head in his passenger seat, many came out and said they knew something was wrong with him!!! Did they really?

2. Overconfidence We tend to think we know more than we do. Common anagrams: WREAT  WATER ETRYN  ENTRY GRABE  BARGE About how many seconds do you think it would it have taken you to unscramble these?

OCHSA  REBTI  ERTOSP 

The Barnum Effect zIt is the tendency for people to accept very general or vague characterizations of themselves and take them to be accurate. Psychologists, as scientists, approach the world of behavior with skepticism.

The Need for Psychological Science

The Scientific Method  Theory  an explanation using an integrated set of principles that organizes and predicts observations  Hypothesis  a testable prediction

Hypothesis Expresses a relationship between two variables. A variable is anything that can vary among participants in a study. Participating in class leads to better grades than not participating.

Operational Definitions Explain what you mean in your hypothesis. How will the variables be measured in “real life” terms. How you operationalize the variables will tell us if the study is valid and reliable. Let’s say your hypothesis is that chocolate causes violent behavior. What do you mean by chocolate? What do you mean by violent behavior?

Experimentation

Descriptive Case Study  Psychologists study one or more individuals in great depth in the hope of revealing things true of us all. Is language uniquely human?

Descriptive  Survey  technique for ascertaining the self-reported attitudes or behaviors of people  usually by questioning a representative, random sample of people  Random Sample  a sample that fairly represents a population because each member has an equal chance of inclusion

Descriptive  False Consensus Effect  tendency to overestimate the extent to which others share our beliefs and behaviors  Population  all the cases in a group, from which samples may be drawn for a study

Descriptive  Naturalistic Observation  observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

Correlational  Correlation Coefficient  a statistical measure of the extent to which two factors vary together, and thus how well either factor predicts the other Correlation coefficient Indicates direction of relationship (positive or negative) Indicates strength of relationship (0.00 to 1.00) r = +.37

Correlational Method zCorrelation expresses a relationship between two variable. zDoes not show causation. As more ice cream is eaten, more people are murdered. Does ice cream cause murder, or murder cause people to eat ice cream?

Correlational  Scatterplot  a graphed cluster of dots, each of which represents the values of two variables  the slope of the points suggests the direction of the relationship  the amount of scatter suggests the strength of the correlation

Correlation Perfect positive correlation (+1.00) No relationship (0.00)Perfect negative correlation (-1.00) Scatterplots, showing patterns of correlations

Correlation Height and Temperament of 20 Men Subject Height in Inches Temperament Subject Height in Inches Temperament

Correlation Scatterplot of Height and Temperament Temperament scores Height in inches

Correlation Coefficient zA number that measures the strength of a relationship. zRange is from -1 to +1 zThe relationship gets weaker the closer you get to zero. Which is a stronger correlation? z -.13 or +.38 z -.72 or +.59 z -.91 or +.04

Illusory Correlation  Illusory Correlation  the perception of a relationship where none exists  For example…

Experimentation  Experiment  an investigator manipulates one or more factors (independent variables) to observe their effect on some behavior or mental process (the dependent variable)  Used to illustrate cause and effect

Experimentation  Placebo  an inert substance or condition that may be administered instead of a presumed active agent, such as a drug, to see if it triggers the effects believed to characterize the active agent  Double-blind Procedure  both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo  commonly used in drug-evaluation studies

Experimentation  Experimental Group  the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent variable  Control Group  the condition of an experiment that contrasts with the experimental treatment  serves as a comparison for evaluating the effect of the treatment

Experimentation  Random Assignment  assigning participants to experimental and control conditions by chance

Independent Variable zWhatever is being manipulated in the experiment. zThe variable whose effect is being studied. If there is a drug in an experiment, the drug is almost always the independent variable.

Dependent Variable The dependent variable would be the effect of the drug. Whatever is being measured in the experiment. It is dependent on the independent variable. In psychology it is usually a behavior or mental process.

Experimentation zConfounding variable-are factors affecting the dependent variable in an experiment. zRandom variables-are uncontrollable factors that could affect the dependent variable in an experiment. zExperimenter bias-occurs when a researcher encourages subjects to respond in a way that supports their hypothesis.

STATISICAL ANALYSIS zStatistical analyses are used to interpret research results. zDescriptive statistics describe data. zInferential statistics are used to draw conclusions and make inferences about what the data mean.

Central Tendency zMean, Median and Mode. zWatch out for extreme scores or outliers. $25,000-Pam $25,000- Kevin $25,000- Angela $100,000- Andy $100,000- Dwight $200,000- Jim $300,000- Michael Let’s look at the salaries of the employees at Dunder Mifflen Paper in Scranton: The median salary looks good at $100,000. The mean salary also looks good at about $110,000. But the mode salary is only $25,000. Maybe not the best place to work.

 Range  the difference between the highest and lowest scores in a distribution  Standard Deviation  It measures the average difference between each score and the mean of the data set or a measure of how much scores vary around the mean  Statistical Significance  a statistical statement of how likely it is that an obtained result occurred by chance

Normal Distribution

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)

APA Ethical Guidelines for Research zIRB- Internal Review Board zBoth for humans and animals.

Animal Research zClear purpose zTreated in a humane way zAcquire animals legally zLeast amount of suffering possible.

Human Research zNo Coercion- must be voluntary zInformed consent zAnonymity zNo significant risk zMust debrief