AP Stat unit 3 Flashcards
What is the definition of a Population in research?
Entire group you are interested in finding out about.
What is a Sample?
Subset of the population, used as an easier way to get a picture of what the population is like.
What does Under Coverage refer to in sampling?
Everyone in populations doesn’t get an equal chance to get surveyed.
What is Non-Response bias?
Out of those selected for sample, some do not respond.
How does Response bias occur?
Interviewer has effect on how the interviewee responds.
What constitutes a Poorly Worded Question?
Question is biased toward a particular answer.
Define Convenience Sample.
Selecting a sample that is convenient (i.e., First ten people in the door).
What is a Voluntary Response Sample?
Individuals volunteer to be in the sample (i.e., Call-in or Online Survey).
What is SRS in sampling techniques?
Simple random sample: Every sample of size n has equal chance of being chosen.
What is a Stratified sampling technique?
Group by a common characteristic, certain number randomly selected from each group.
What does Cluster sampling involve?
Group, randomly select entire groups.
Describe Systematic sampling.
Counting off by a random number and selecting only the nth individuals (i.e., Gym class).
What is Multistage sampling?
Combination of any of the previous ‘good’ sampling techniques.
Name one way to Randomize samples.
Calculator: Assign each person a digit, RandInt(first individual’s #, last individual’s #, # of individuals you want to select).
What is the Random Digit Table method?
Assign numbers to individuals, indicate starting line, read chunks of equal digits, select those that have assigned individuals, ignore repeats.
What is the recommended method for random sampling?
Pulling from a Hat: Write names on slips of paper, stir the hat, select a name, replace the slip, stir, repeat ignoring repeats.
Why is random sampling important?
Random samples ensure that our results are not biased in any way.
What is an Experimental Unit?
Individuals who receive treatments.
Define Subject in experimental design.
Human experimental units.
What is an Explanatory Variable?
A variable that helps explain or influences changes in a response variable.
What is a Response Variable?
Measures outcome of a study.
What are Factors in experimental design?
Variables that help explain a response variable.
What are Levels of Treatment?
Values of the factors that you are testing.
What is a Placebo?
Dummy treatment.
