Experimental Design Flashcards Preview

AP STATS > Experimental Design > Flashcards

Flashcards in Experimental Design Deck (19):
1

observational study

simply observe the individuals and measure the results cause and effect cannot be demonstrated.

2

experimental units

the smallest "unit" on which treatment is imposed

3

response variable

what is measured after treatment

4

explanatory variable

the factor that is manipulated

5

control

things that we know affect the outcome but are not being studied must be taken into account in the design of the experiment

6

randomization

treatments must be randomly assigned in order for an experiment to be valid. The purpose of this is to even out the impact of factors we cannot control.

7

replication

many subjects should be included in the study often, experiments are repeated in order to get representative subjects.

8

blocking ( sometimes )

grouping similar subjects together to reduce the effects of things that cannot be controlled.

9

single blind

when either the subjects/treatment administrators/technicians or the evaluators if the data do not know what treatments are applied to what subjects.

10

double blind

when neither the subjects/treatment administrators/nor the evaluators of the data do not know what treatments are applied to what subjects.

11

Placebo effect

"faux" testament: humans tend to show a response ( typically around 20% of the time ) even when a placebo is administrated

12

statistically significant

the difference in the response for the control group and the response group is too large to occur by chance.

13

confounding variables

factors that are linked in the response variable and cannot be separated from them. Factors not in the experiment that might effect the outcome. *try to control for*

14

experiment

deliberately impose an experiment

15

retrospective

look over past records and events

16

prospective

start now and look into the future

17

causation

can be implied in an experiment

18

association

can be implied in an observational study

19

control group

an established baseline treatment level can be a placebo group or the "before" level in a before and after treatment.