AP Statistics: Unit 3

who the data is collected from

the entire group attempting to collect data from

looking at past data

looking at data over multiple days/month/years

to generalize about a population based on one study; can only be done is all participants are randomly selected/sampled; rare

casual relationship between two events; one caused another to happen

treatments are imposed

treatments are not imposed

1.) Define the population

2.) Choose your sample size

3.) List the population

4.) Assign numbers to the units

5.) Find unique random numbers

6.) Select the samp

1.) Define the strata (homogenous groups) needed

2.) Define the sample size needed

3.) Randomly select from each strata

4.) Review and combine results

1.) Define the populations

2.) Divide into clusters (heterogenous groups)

3.) Randomly select (a) cluster(s) to use as the sample

1.) Decide a sample size

2.) Randomly select a number

3.) Choose every nth subject starting from that number (n)

Only surveying those “easy to reach”

Allows people to choose to be in the sample by responding to a general invitation; self-selecting

When questions are worded in a way that persuades the responder

When an individual refuses to respond/participate

When there is a systematic pattern of inaccurate answers to a survey question; lying

When some members of the population are less likely to be chosen or cannot be choses

Either the subjects or the people who interact with them do not know which treatment a subject is recieving

either the subjects nor those who interact with them do not know which treatment a subject is receiving

Treatment that has no active ingredient, but is otherwise like other treatments; control group

Describes the fact that some subjects in an experiment will respond favorably to any treatment, even an inactive treament

Unit to which a treatment applies; who is the experiment on; subjects

Used to provide a baseline for comparing the effects of other treatments; does not have to be a control group

a variable related to the explanatory variable and influences the response causing a misconception of the two being associated

a categorical explanatory variable

values of a factor

a particular combination of values for the factors

compare 2 or more treatments

randomly assigns experimental units to treatments

keep all other variable that might affect the response the same for all groups

use as many experimental units as possible in each group

assigns experimental units to the treatments strictly by chance; random half are to do one treatment and the other are to do other

separates experimental units into groups based on some homogenous characteristic and then randomly assigned treatments within each block

creates blocks by matching pairs of similar experimental unit; the pair can be just one person doing both experiments seperately