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Exam 1 Review. Exam Thursday Please bring answer sheet. Important topics and some review questions. Review. All Those Variables!. Confused?? So am I Let’s get them straightened out. Independent. Dependent. Classification. Stimulus. Extraneous. Response. What?. Mediating.
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Exam 1 Review Exam Thursday Please bring answer sheet Important topics and some review questions
Review All Those Variables! • Confused?? • So am I • Let’s get them straightened out Independent Dependent Classification Stimulus Extraneous Response What? Mediating Organismic Moderating Confounding
Variables, Variables, Variables • Independent = manipulated • Dependent = measured (or observed) • Classification = existing categories • Really a dependent variable • Treated like an independent variable • Extraneous = relevant but ignored • Stimulus, Response, Organismic • Don’t worry about them!
Correlational Research (and Observational Research) • We measure or observe Dependent variables • We ignore the Extraneous variables • But they may influence the results • If so, and if they affect both the variables involved in a correlation, then they are … • Confounding variables • i.e., they make it impossible to explain the correlation
Correlational Research(and Observational Research) • Confounding variables • might explain observed relationships among dependent variables • So we look to see if they are … • Mediating variables! • We can test for the effect of mediating variables, but to do so … • we need to measure them, so now they are … • Dependent variables Aaargh!
Correlational Research(and Observational Research) • Mediating variables • are Extraneous variables at first • are Confounding variables as well • and, when measured, become Dependent variables • but they are not the same as … • Moderator variables • which change the observed relationships among other dependent variables
What? Still Confused?This may help: Whether or not a variable is a confounding variable is not under your control Whether or not a variable is a mediating variable is not under your control – although you can find out Whether or not a variable is an extraneous variable is under your control – you can measure it Thus, you can find out if an extraneous variable is a mediating variable by measuring it
Rationalism and Empiricism • Why are empiricism and rationalism both important in developing scientific theories?
Sample Question 1 Which of the following statements would be made by a scientist who is using rationalist principles? (a) “I don’t believe in ESP because there are no data to show that it occurs reliably” (b) “I don’t believe in ESP because it’s inconsistent with everything else we know about perception” (c) “I don’t believe in ESP because it violates my religious and moral beliefs”
Sample Question 1 How do we know what we know? Empiricism: Through observation Rationalism: Through logical consistency with other things we know Which of the following statements would be made by a scientist who is using rationalist principles? (a) “I don’t believe in ESP because there are no data to show that it occurs reliably” (b) “I don’t believe in ESP because it’s inconsistent with everything else we know about perception” (c) “I don’t believe in ESP because it violates my religious and moral beliefs”
Models • Why do we use models? • What do we look for in a model?
Sample Question 2 Which of the following models would be most useful to a psychologist who is studying social judgment? (a) A model of social judgment that can explain any results the psychologist might find (b) A model of social judgment that makes predictions that turn out to be wrong occasionally
Sample Question 2 Which of the following models would be most useful to a psychologist who is studying social judgment? (a) A model of social judgment that can explain any results the psychologist might find (b) A model of social judgment that makes predictions that turn out to be wrong occasionally Models must be testable They don’t have to be perfect
Variables • What are independent variables and dependent variables? How do classification variables fit into this distinction? • How do you identify possible extraneous variables? Why are they important?
Sample Question 3 Dr Glidden performed an experiment to study the effects of noise. She want to find out if it would interfere with problem solving more for skilled problem solvers than for poor problem solvers? What kind of variable is “skilled versus poor problem solver”? (a) Dependent (b) Independent • Classification • Extraneous
Sample Question 3 Dr Glidden performed an experiment to study the effects of noise. She want to find out if it would interfere with problem solving more for skilled problem solvers than for poor problem solvers? What kind of variable is “skilled versus poor problem solver”? (a) Dependent (b) Independent • Classification • Extraneous Dependent = measured: the effect Independent = manipulated: the cause Classification = non-manipulated, but not an effect either
Scales of Measurement • What properties of the number system are relevant to measurement? • What can we do with interval scales that we can’t do with ordinal scales? • How do we know if we have an interval scale or not?
Sample Question 4 I’m fixing dinner for Albert and Brenda. Albert rank orders his preferences: Steak, Fish, Pizza, Chicken. Brenda rank orders them Pizza, Fish, Steak, Chicken. What can I conclude? (a) On the average, steak and fish are equivalent (b) I’d better not fix chicken
Sample Question 4 I’m fixing dinner for Albert and Brenda. Albert rank orders his preferences: Steak, Fish, Pizza, Chicken. Brenda rank orders them Pizza, Fish, Steak, Chicken. What can I conclude? (a) On the average, steak and fish are equivalent (b) I’d better not fix chicken Ordinal scales give information about order Calculating averages requires an interval scale
Sample Question 5 For assignment 2 you used trustworthiness judgments, then calculated correlation coefficients, which are based on means and variances. Was this legitimate? (a) No – we only had an ordinal scale (b) Yes –trustworthiness was measured on an interval scale (c) Maybe, we don’t know for sure
Sample Question 5 For assignment 2 you used trustworthiness judgments, then calculated correlation coefficients, which are based on means and variances. Was this legitimate? (a) No – we only had an ordinal scale (b) Yes –trustworthiness was measured on an interval scale (c) Maybe, we don’t know for sure We rarely know for sure. We proceed anyway; if our theories are supported we probably have an interval scale
Operational Definitions • Why are operational definitions important? • What makes a definition operational?
Sample Question 6 Charlie is studying social adjustment in young children. Which is the least like an operational definition of social adjustment? (a) A child’s understanding of other children’s feelings (b) Teachers’ ratings of a child’s social adjustment (c) A child’s score on a test of social adjustment
Sample Question 6 Operational definitions should tell you what to do Charlie is studying social adjustment in young children. Which is the least like an operation definition of social adjustment? (a) A child’s understanding of other children’s feelings (b) Teachers’ ratings of a child’s social adjustment (c) A child’s score on a test of social adjustment
Sample Question 7 Dan defines “Love for person X” as an increase in pulse rate in the presence of X. Deidre defines “Love for person X” as a person’s response on a rating scale when asked how much he or she experiences love for X. How should we settle this disagreement? (a) Only Dan’s definition is operational (b) Only Deidre’s definition is operational (c) We should find out how Love-per-Dan and Love-per-Deidre are related, if at all
Sample Question 7 Dan defines “Love for person X” as an increase in pulse rate in the presence of X. Deidre defines “Love for person X” as a person’s response on a rating scale when asked how much he or she experiences love for X. How should we settle this disagreement? (a) Only Dan’s definition is acceptable (b) Only Deidre’s definition is acceptable (c) We should find out how Love-per-Dan and Love-per-Deidre are related, if at all They are both operational Let’s find out if they are the same thing If they are we have convergent validity
Low Constraint Research • When is it appropriate? • What are its limitations?
Sample Question 8 For which of the following topics would low constraint research be most suitable? (a) Compare two methods for teaching statistics (b) Find out if training in conflict resolution reduces aggression in teenagers (c) Find variables related to dating behavior that might be worth studying further
Sample Question 8 For which of the following topics would low constraint research be most suitable? (a) Compare two methods for teaching statistics (b) Find out if training in conflict resolution reduces aggression in teenagers (c) Find variables related to dating behavior that might be worth studying further Use low constraint research for exploration
Sampling Issues • Why is sampling a concern in research? • What are the major sampling issues in low constraint research?
Sample Question 9 Desdemona is interested in the dynamics of family interactions. She spends hours watching the families that eat at a popular restaurant that is frequented by almost everyone in town. Which sampling issue is probably of least concern in this case? (a) Participants (b) Situations (c) Behaviors
Sample Question 9 Desdemona is interested in the dynamics of family interactions. She spends hours watching the families that eat at a popular restaurant that is frequented by almost everyone in town. Which sampling issue is probably of least concern in this case? (a) Participants (b) Situations (c) Behaviors Plenty of participants in this case, but all three of these are important
Confounding • Why is confounding a major concern in low constraint research? • How can one reduce the problems of confounding in low constraint research?
Sample Question 10 In her study, Desdemona observed that expressions of anger by parents are more common in larger families. It would be reasonable to conclude that, if you are the parent of a large family who takes your kids to a restaurant, _____ (a) it’s better to take them a few at a time (b) you can expect to express anger more often than parents of small families (c) Both conclusions are reasonable (d) Neither conclusion is reasonable
Sample Question 10 In her study, Desdemona observed that expressions of anger by parents are more common in larger families. It would be reasonable to conclude that, if you are the parent of a large family who takes your kids to a restaurant, _____ (a) it’s better to take them a few at a time (b) you can expect to express anger more often than parents of small families (c) Both conclusions are reasonable (d) Neither conclusion is reasonable Prediction is OK Causal inference is not
Differential Research • What is the purpose of differential research? • What kind of conclusions can one draw from differential research?
Sample Question 11 Eric counted children’s use of pronouns in a classroom. He found that tenth graders use the word “We” a lot, fifth graders use it rarely. He concluded that between fifth and tenth grade children acquire an understanding of social groups. What is not a problem with his conclusion? (a) He may be over-generalizing his results (b) Cohort effects may influence the results (c) He has no operational definition for “pronoun” (d) There may be several confounding variables
Sample Question 11 Eric counted children’s use of pronouns in a classroom. He found that tenth graders use the word “We” a lot, fifth graders use it rarely. He concluded that between fifth and tenth grade children acquire an understanding of social groups. What is not a problem with his conclusion? (a) He may be over-generalizing his results (b) Cohort effects may influence the results (c) He has no operational definition for “pronoun” (d) There may be several confounding variables He counted “we”s. But he ignored the potential confounding
Correlations What kind of conclusions can one draw from correlational research ? How should one interpret the numerical value of a correlation?
Sample Question 12 Fiona studied recreational runners, and found a correlation of 0.5 between number of injuries and time spent stretching. Which of the following conclusions is appropriate? (a) Stretching prevents injuries (b) Stretching makes injuries worse (c) Having an injury makes people want to stretch more (d) Stretching can explain one quarter of the variance in running injuries
Sample Question 12 Fiona studied recreational runners, and found a correlation of 0.5 between number of injuries and time spent stretching. Which of the following conclusions is appropriate? (a) Stretching prevents injuries (b) Stretching makes injuries worse (c) Having an injury makes people want to stretch more (d) Stretching can explain one quarter of the variance in running injuries Prediction is assessed by r2 Causal inference is out Look for other explanations!
Mediating Variables What is a mediating variable? How is it related to confounding? How do we test for the effects of a mediating variable?
Sample Question 13 A study found a large negative correlation between fidgeting and obesity. The correlation of fidgeting and obesity, partialing out amount of exercise, was almost zero. Which of the following statements is appropriate? (a) Exercise mediates the relationship between fidgeting and obesity (b) Fidgeting and obesity mediate the effects of exercise (c) People who don’t exercise should try fidgeting to lose weight
Sample Question 13 A study found a large negative correlation between fidgeting and obesity. The correlation of fidgeting and obesity, partialing out amount of exercise, was almost zero. Which of the following statements is appropriate? (a) Exercise mediates the relationship between fidgeting and obesity (b) Fidgeting and obesity mediate the effects of exercise (c) People who don’t exercise should try fidgeting to lose weight Exercise accounts for the original correlation
Sample Question 14 A study of college students found a positive correlation between GPA and depression in women. However, there was no correlation between GPA and depression in men. In this study sex appears to be _____ (a) a mediating variable (b) a moderator variable (c) an extraneous variable (d) a confounding variable
Sample Question 14 A study of college students found a positive correlation between GPA and depression in women. However, there was no correlation between GPA and depression in men. In this study sex appears to be _____ (a) a mediating variable (b) a moderator variable (c) an extraneous variable (d) a confounding variable The correlation changes as a function of sex
Dr. McKenzie surveyed alcohol use on campus and found that students with lower GPAs engage in more binge drinking than students with higher GPAs. Which (if any) of the following conclusions is reasonable? (a) Excessive binge drinking contributes to poorer academic performance (b) Binge drinking is a common reaction to poor academic performance (c) Both are OK (d) Neither is OK
Dr. McKenzie surveyed alcohol use on campus and found that students with lower GPAs engage in more binge drinking than students with higher GPAs. Which (if any) of the following conclusions is reasonable? (a) Excessive binge drinking contributes to poorer academic performance (b) Binge drinking is a common reaction to poor academic performance (c) Both are OK (d) Neither is OK Both imply causal explanations