sampling and the experiment

Question 1

population

Answer 1

the larger group to which results are generalized; defined group of persons, objects

Question 2

sample

Answer 2

subgroup of a population

Question 3

sampling bias

Answer 3

individuals selected for a sample over or under represent population attributes

Question 4

inclusion criteria

Answer 4

traits of target (and accessible) population that qualifies someone as a subject

Question 5

exclusion criteria

Answer 5

factors that preclude or prevent someone from being a subject

Question 6

random sampling

Answer 6

Every unit has equal chance of having some of the characteristics that are present throughout population

Question 7

random assignment

Answer 7

sometimes randomization doesn’t work, groups might have important differences

Question 8

sampling error

Answer 8

The difference between sample averages (statistics) and population averages (parameters)

Question 9

what provides the most confidence in sample validity because, in the long run, it produces samples that most accurately reflect population characteristics

Answer 9

random sampling

Question 10

control group

Answer 10

used to compare with the treatment group to see if results are due to manipulated variable or due to chance

Question 11

extraneous variable

Answer 11

out of control variables

Question 12

confounding variable

Answer 12

extraneous variables that are not controlled; contaminate independent variable

Question 13

lurking variables

Answer 13

confounding variables that you don’t know about or discover later

Question 14

blinding

Answer 14

can be single or double where either the subject, investigator or both are unaware of the identity of treatment