Notes 1 – Planning a Study
the entire group we want information about
population
Samples are __________________ if they are systematically not representative of the desired population.
biased
what are the things on which the experiment is done
experimental units
The explanatory variables in an experiment
factor
a part of the information we actually examine to gather information about the population
sample
When a sample is comprised entirely of volunteers or people who choose to participate, the sample will typically not be representative of the population
voluntary response
When the experimental units are toman beings
subjects
The various groups the factors take
level
collects data from every individual in the population
census
occurs when some groups in the population are left out of the process of choosing a sample
undercoverage
A specific experimental condition applied to the units
treatment
when the subject does not know what treatment they are recieving to remove the power of suggestion
binding
observes individuals and measures variables of interest
observational study
occurs when an individual chosen for a sample cant be contacted or refuses to respond
nonresponse
A study if done to try and find the correlation between verbal and math SAT scores. The scientist wants to use the verbal score to predict the math score.
Observational study
Explanatory - verbal score
response - math score
experiments in which the subject and administrator do not know who recieves what treatment
double bind
deliberately imposes some treatment
experiment
bias caused by the behavior of the respondent or interviewer
response bias
Some breast cancer patients were given each a new treatment. The patients were closely followed to see how long they lived following surgery.
experiment
explanatory - new treatments
response - length of life
________ group is treated identically in all respects to the group receiving the treatment except that the members of the control group do not receive the treatment.
Control