WEEK 5- 10.1 experiments

Question 1

key components of experiments

3

Answer 1

1. randomized intervention
2. random assignment
3. design- between or within participants

Question 2

between participants

Answer 2

participants assiged to different groups, the different groups are compared to eachother. (each gets 1 treatment)

Question 3

within participants

Answer 3

participants all receive the same intervention, but have different sequential orders of the treatment.

Question 4

types of experiments by setting

4

Answer 4

1. labratory
2. field
3. natural
4. survey

Question 5

labratory experiment

Answer 5

artificial setting, standardized, full control

Question 6

field experiment

Answer 6

embedded in the real world, less control
treatment is still randomized
control less complete as people are exposed to other factors

Question 7

natural experiment

Answer 7

technically not an experiment due to lack of random assignment
merely a comparison between groups which cannot be seen as equivalent due to non-random assignments

Question 8

survey experiment

Answer 8

embedded in population survey
you get advantages of a representative population survey while testing causal mechanisms using randomized treatments

Question 9

basic experimental designs

Answer 9

1. post test only
2. pretest- post test

Question 10

post test only design

Answer 10

random assign ent into two groups
g1 has a manipulation of the treatment variable leading to y1
control group leading to y2
you don’t know whether the groups are equivalent

Question 11

pretest postest design

Answer 11

random assignment to two groups

measuring the dv before and after the treatment effect
allowing for analysis on the changes between pre-test and posttest

=> allows you to precisely see if the outcome measure changes in resopnse to the treatment, controlling for the baseline measurement in the begining

Question 12

other experimental designs

3

Answer 12

1. solomon four group
2. delayed effects
3. factorial

Question 13

prospect theory

Answer 13

when people see a positively framed scenario, they become risk averse, and go with the safe option

when people see a negatively framed scenario, they become risk taking, and go with the risky option

Question 14

counterfactual assumption

Answer 14

assuming that if the cause or treatment were different, the outcome or decision would be different too.
- fundamental problem of causal inference\

Question 15

unit homogeneity

Answer 15

for testing our causal r.ship, we can resolve this if we have an equivalent case or unit that would be exposed to another cause, and we hope wo will take decision b
=> the cause has a consistent effect
=> homogeneity is when they react the same

Question 16

conditional independence

Answer 16

IV is assigned independent of DV
1. no endogeneity (reciprocal causation)
2. no selection bias
3. no ommited variable bias (confound)

Question 17

assumptions of experiments

2

Answer 17

1. same unit, different treatment
2. conditional independence (iv is independent of dv)

Question 18

matching (quasi)

Answer 18

used when participant number is low, and the researcher wants to make sure that the experimental groups are as equivalent as possible.

Question 19

solomon 4 group design

Answer 19

participants are randomly assigned to four groups (2 treatment, 2 control)
=> you can determine if the pretest sensetizes the participants

Question 20

delayed effects design

Answer 20

in one treatment and control group the outcome is measured immediately, and the other treatment and control group is measured only later.

Question 21

why is factorial design used the most?

Answer 21

used most often, bc there’s more than one variable that needs consideration

Question 22

factorial design

Answer 22

1. CONTROL: control group w/ pre test and post test measurement of y
2. MAIN EFFECT 1: a treatment group where only the first experimental treatment is present
3. MAIN EFFECT 2: a second treatment group where the second experimental treatment is present
4. INTERACTION EFFECT: third treatment group where both treatments are present

Question 23

factorial design

Answer 23

1. CONTROL: control group w/ pre test and post test measurement of y
2. MAIN EFFECT 1: a treatment group where only the first experimental treatment is present
3. MAIN EFFECT 2: a second treatment group where the second experimental treatment is present
4. INTERACTION EFFECT: third treatment group where both treatments are present

Question 24

zimbardo and milgram studies are examples of…

Answer 24

post test only measurement
=> but is milgram really an experiment? there’s no randomized treatment
=> stanford prison is. a real experiment

Question 25

when are experiments useful?

Answer 25

1. communication, language, public opinion
   (priming, framing, persuasion)
2. campaigning- classic domain of field experiments
3. policy making- effectiveness of different policies (natural)
4. decision making of citizens and political elites
   - proces tracing

Question 26

validity problems with experiments

Answer 26

1. internal validity tends to be high becuase they make causal inferences possible
2. ecological validity tensd to be low because the extent to whcih the research reflects real-life situations is debatable
3. problems about reactivity- placebo effects may lead to participants mis-estimating the effects, and demand characteristics (giving the researcher what they want)
4. external validity: weirc

Question 27

experiments ethics

Answer 27

treatment usually requires concealment or deceptino- the use has to be well justified, and debriefing is required
in field studies, debriefing is often not possible