Lecture 3 - Part I And II

Question 1

What is the null hypothesis?

Answer 1

A statement of no relationship among the variables being tested

Question 2

What is the research / Alternative Hypothesis?

Answer 2

The predicted relationship between the variables being tested

Question 3

What is research validity?

Answer 3

Truthfulness of a causal inference that is made from the results of a research study

Question 4

What is internal validity?

Answer 4

Degree of confidence that the causal relationship being tested is trustworthy and not influenced by other factors or variables within the context of the present study

Question 5

What is external validity?

Answer 5

The extent to which results from a study can be generalized to other
1. People
2. Settings
3. Treatments
4. Outcomes
5. Times

Question 6

What are the 5 types of external validities?

Answer 6

1. Population validity
2. Ecological validity
3. Treatment population validity
4. Outcome validity
5. Temporal validity

Question 7

What are the 3 conditions for making the claim of causation?

Answer 7

1. A must be correlated with B
2. Changes in A must precede changes in B
3. No plausible alternative explanation exists for the relationship between A and B

Question 8

In the ABCD framework, what does each letter represent?

Answer 8

A: Independent Variable
B: Dependent Variable
C: Mechanism for how A affects B
D: Alternative Explanation

Question 9

What is an observational study?

Answer 9

Researchers collect data by observing and making inferences based on that data. No interference from researchers

Question 10

What is an experimental study?

Answer 10

A study where researchers control the assignment of treatments to subjects using a chance mechanism

Question 11

What are the benefits of the experimental approach?

Answer 11

1. Causal inferences can be drawn from the data collected
2. Experimental approach grants researchers greater control over the other variables

Question 12

What are the cons of the experimental approach?

Answer 12

1. Does not test the effect of non-manipulated variables
2. There may be ethical or practical problems with variable control
3. The environment does not allow for generalization to real-life situations
4. Cost

Question 13

Why can’t lab findings be generalized to real life situations?

Answer 13

1. Subjects know they are observed by researchers
2. Subjects are placed in an unfamiliar situation and asked to make unfamiliar decisions

Question 14

What is a laboratory experiment?

Answer 14

A controlled scientific investigation in a laboratory environment, often situated in a university computer lab or classroom often with college students participating.

Participants typically make decisions within an artificial context.

Question 15

What is a field experiment?

Answer 15

Research using some controlled elements of traditional laboratory experiments, but takes place in natural/real world settings

Question 16

What is an artefactual field experiment?

Answer 16

Same as conventional lab experiments but with a non-standard subject pool

Question 17

What is a framed field experiment?

Answer 17

Similar to artefactual field experiments but with field context in either the commodity, task or information that the subjects use.

Question 18

What is a natural field experiment?

Answer 18

Same as framed field experiment but subjects do not know they are participants in an experiment

Question 19

What are the 2 properties of good measurement?

Answer 19

1. Reliablity : consistency and stability of scores
2. Validity : accuracy of inferences, interpretation, or actions made on the basis of test scores

Question 20

What are 2 rules for economic-specific validity?

Answer 20

1. Decisions should be properly incentivized
   - earnings based on participant’s decisions
   - paid no lower than average hourly rate
2. Use of deception is not allowed unless strictly necessary

Question 21

What is the name for the experimental design involving 2 treatment variables?

Answer 21

2x2 factorial design

Question 22

What is a 2 level and 3 level experimental design?

Answer 22

2 level: 1 control 1 treatment condition
3 level: 1 control 2 treatment conditions

Question 23

What is a recommended minimum number of observations in each cell for a 2x2 design?

Answer 23

30

Question 24

What are the 2 principles of manipulating a variable?

Answer 24

1) the manipulation indeed varies variable A
2) the manipulation only varies variable A

Question 25

What are the 4 steps for manipulating variables?

Answer 25

1. Determining the number of treatment/manipulated variables 2. Determine the manipulation of the variables 3. Manipulation check 4. Control techniques

Question 26

What are the 5 control techniques?

Answer 26

1. Between subject design or within subject design 2. Randomization 3. Order effect 4. Demand effect 5. Wealth/income effect

Question 27

What is the difference beween within-subject and between-subject?

Answer 27

Between: each individual exposed to only 1 treatment condition Within: each individual exposed to more than one treatment condition

Question 28

What are the benefits of within-subject experiment?

Answer 28

1. Can control for many factors which may disturb your results 2. Requires a smaller sample size than between subjects, leading to increased statistical power

Question 29

What are the negatives of a within-subject design

Answer 29

1. Carryover effect - effect of prior experimental conditions 2. Demand effect - participants try to interpret experimenter's intentions and act accordingly

Question 30

Advantage of between subject experience

Answer 30

Each participant enters the study fresh and naive with respect to the procedures to be tested

Question 31

What is the effect of randomization on groups

Answer 31

It provides indirect control of uncontrolled variables by ensuring their eventual independence of treatment variables.

Question 32

What is a common technique for creating equivalent groups?

Answer 32

Random assignment Everyone has an equal chance of being placed in any of the groups, typically using a chance mechanism to determine which condition a subject is assigned to.

Question 33

What is the order effect?

Answer 33

An influence on a particular trial that arises from its position in a sequence of trials.

Question 34

In a session with multiple decision making tasks, where should the key task of interest be positioned?

Answer 34

At the outset

Question 35

What are solutions to the demand effect?

Answer 35

1. Use a between subject design 2. Create incentives that make it costly to deviate from true preferred choices

Question 36

What is the wealth effect?

Answer 36

In the incentive to exercise paper, one group exercised more and this reason could be due to experiment payout being higher than other groups, creating a wealth effect

Question 37

Solution to wealth effect

Answer 37

All subjects receive an equal amount of payment regardless of treatment condition

Question 38

How does wealth effect come into play in experiments with multiple rounds?

Answer 38

Participants earnings in prior rounds may influence their subsequent decisions

Question 39

Solution to wealth effect in experiments with multiple rounds?

Answer 39

Subjects are paid according to results from a randomly selected period