Other's On-Line Resources (Chapter 5)
| Creating
a Simple Random Sample |
- Description:
In this interactive on-line resource, you get to specify (a) the
size of the population from which your sample will be drawn, (b)
the size of the sample you want, and (c) whether or not there
will be "sampling with replacement." Then you'll be given the
ID numbers for the n items randomly selected from the larger set
of N items.
- What to Do:
- Click on the colored title of this on-line resource,"Creating
a Simple Random Sample."
- In the boxes that say "This set is from __ to __," change
the first number to 1 and then change the second number to
the size of your group (i.e., to the numerical value of N).
- Type in your desired sample size where it says "You are
choosing a set of size __."
- Choose either "Allow Repeats" or "Don't Allow Repeats" depending
on whether you want to sample WITH replacement or sample WITHOUT
replacement, respectively.
- Click on the "GO!" button and then look at the n numbers
that appear. These numbers are the ID numbers for the items
randomly selected to be in your sample.
- Sky Huck's Puzzle Question:
What do you think will happen if you make n larger than N and
then sample without replacement? After making your guess, say
(1) "This set is from 1 to 10," (2) "Your are choosing a set of
size 11," and (3) "Don't Allow Repeats." Then click "GO!" and
look to see if your prediction was right or wrong?
|
| Political
Polls |
- Description:
In this interactive on-line resource, you'll play a little game
in which you assume the role of a researcher who's been hired
as a statistical consultant for a politician. The politician,
of course, wants you to conduct a poll. Your job is to determine
what kinds of people to sample. After you make your sampling decisions,
you'll get to see how good your polling results are.
- What to Do:
- Click on the colored title of this on-line resource,"Political
Polls."
- Read the information on the first screen, and then click
on the trianglular picture that says"Sampling the Electorate."
- Read the information on the next screen, and be sure to
click on the 2 "clickables" directly under the question, "Are
you ready to go to work?"
- Make your polling decisions, and then click on the button:
"Poll a Sample of the Population." The next screen will automatically
pop up telling you how well you did.
- Sky Huck's Puzzle Question:
If you play this little game again (by first clicking on the "Clear
Selections" button and then making new choices), what's the best
SINGLE demographic category to select? What's the SINGLE worst
category to select? And how can you determine whether your answers
to these 2 questions are correct?
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