Research Methods Science of Psychology

Psychology as Science Critical Thinking Overconfidence Hindsight Bias Overconfidence: the tendency to be more confident than correct--to overestimate the accuracy of one's beliefs and judgments. We think that we know more than we actually know Hindsight Bias: Knew it all along phenomenon, tendency to have foreseen outcome of events way after the fact. ex:9/11

Skepticism vs Cynicism Assumptions Evidence Fact What if anything would ever cause you to change your mind? Hamm: Nothing Nye: Evidence

Scientific Method Theory Hypothesis Operational Definition Replication Hypothesis: Statement of relationship between two variables based on testing and observations.

How do we observe behavior? Case Study Survey Method Random Sampling Naturalistic Observation

Correlation Prediction of one variable to another Correlational Coefficient -1 +1 Are correlations we believe to exist with no actual correlation exists. Many times you are thinking about a song you turn on the radio and it is playing, or you are thinking about someone and that person happens to give you a call or a text, you assume that there is some supernatural correlation or some other explanation other than random chance. Lotto tickets Machine in Vegas with the slots that gives the illusion of correlation when in fact, non exists

Illusory Correlations Perceived Correlation Cards

Experimental Method Correlational vs Experimental Manipulation of Variables Reduce Confounding Variables Random Assignment Random Selection Control Group Vs Experimental Group

Eliminating Confounding Variables Single Blind Study Double Blind Study Placebo Effect Placebo: Results Caused by assumption

Independent vs Dependent Variable DV= Measured Variable IV= Manipulated Variable Independent variable is the one that the researcher manipulates Dependent variable is the behavior or mental process that is being measured. In other words it is the factor that may change as a result of the independent variable . If the dependent variable changes only when the independent variable is changed then the researcher could can conclude that the change in the independent variable caused the change in the dependent variable. Easier way to see it is that the independent variable is the cause and the dependent variable is the effect An even easier way to figure it out is to put it in an If then situation The sentence would be IIF……(independent variable) …..THEN….(dependent variable) “If students study for a quiz the night before , rather than in the morning then they will get higher scores on the quiz”

Measures of Central Tendency Mean Median Mode

Measures of Variability Range Variance Standard Deviation Variability just describes the spread of scores in a set of research data Range is the easiest as it is the difference between the lowest and highest scores, however it only provides a crude measure of variance. Variance and standard deviation indicate the degree to which scores differ from each other and vary around the mean value for the set Variance is found by finding the difference between the value and mean , squaring each diffrence and then summing the squared diffrences and then dividing them to find the average. The standard deviation is the square root of the varience.

Standard deviation tells us how different the scores are from each other.

Statistical Significance Population Size Relationship between variables is not due to chance

Ethics in Psychology APA Informed Consent Debriefing Participants are told enough to know if they want to participate in the study or not Debriefing is letting the participants know the results of the study

Quick Quiz: Operationally Define Doing HW Difference between random selection and assignment What is a confounding variable? Example Which type of observation is best to see humans behaving in normal environmental conditions? Define hindsight bias Which one of the following is the weakest correlation: 1: -.70 2. .50 3. -.88 4. .52

Quick Quiz Per 7 What is a double-blind study? Define confounding variable and provide an example. What are the benefits and the downsides of Case Studies? Difference between random selection and assignment What is the “Knew it all along phenomenon”? Which one of the following is the strongest correlation? 1) .89 2) -.95 3) .50 4) .04 5) -.80

FRQ Professor Hahn received a grant to study the relationship between childhood obesity and video game playing. Answer the following questions about Professor Hahn's research study: A. Explain how Professor Hahn could use each of the following research methods to study this topic: • Case study • Survey • Naturalistic observation B. Design an experiment Professor Hahn could use to investigate this topic, including the following terms in the context of your design. • Operational definition • Independent and dependent variable • Random assignment C. Explain how Professor Hahn's experimental design would conform to ethical guidelines.

Answers Point 1: Case Study: Students should note that Professor Hahn should choose one child and gather detailed information about that child's video game habits and health (such as eating habits, weight, and other related factors). Point 2: Survey: Students should note that Professor Hahn should gather data from a large sample of children representing his population of children through a survey measuring both video game playing and obesity. Point 3: Naturalistic observation: Students should note that Professor Hahn should gather data about children's video game habits and health by observing behaviors in a public setting. Point 4: Operational definition: Students should provide at least one correct operational definition for video game playing (such as timing how long children play video games) and obesity (such as calculating body mass index). Point 5: Independent and dependent variables: Students should identify video game playing as the independent variable and obesity as the dependent variable in the experimental design. Point 6: Random assignment: Students should explain how participants could be randomly assigned to either the experimental condition or the control condition (the conditions should differ based on the independent variable: video game playing).