Other's On-Line Resources (Chapter 2)
| Fun
With Histograms |
- Description:
Using this interactive on-line resource, you can play with a histogram--building
it any way you wish--and immediately see the impact of your actions
on your data set's mean, median, SD, and skewness.
- What to Do:
- Click on the colored title of this on-line resource: "Fun
With Histograms."
- After the next screen pops up, click on the "Begin" button
that's located under the heading "Mean and Median."
- On the new screen that pops up, you'll see a blue histogram
and (to the left of the histogram) a set of descriptive statistics
for the histogram's data. By clicking above or below any of
the building blocks that create a vertical column in the blue
histogram, you can make that particular column taller or shorter.
- As you make changes to the histogram's shape, note the changes
in the desriptive statistics: N, the mean and median, the
standard deviation, and skewness.
- Sky Huck's Puzzle Question:
With N equal to 15, it's possible to build a histogram such that
(a) the range extends from 1-9, (b) no frequency = 0, (c) the
mean and median are each exactly twice as large as the standard
deviation, and (d) skewness = 0. Can you accomplish this feat?
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| More
Fun With Histograms |
- Description:
This interactive on-line resource allows you to change the width
of the columns in a histogram and thereby see that the true distributional
shape of data can be MISREPRESENTED if the column width is not
selected properly.
- What to Do:
- Click on the colored title of this on-line resource: "More
Fun With Histograms."
- After the next screen pops up, read the initial paragraph
of text.
- Move the black triangle (under the horizontal "bin width"
bar) to change the width of the columns in the histogram,
noting how the histogram's shape changes.
- Sky Huck's Puzzle Question:
Was the mean eruption duration closer to the shortest eruption
or the longest eruption?
|
| How's
Your Reaction Time? |
- Description:
In this interactive resource, you first generate data by performing
a simple reaction-time task. Then, you get to see how you did,
with your data summarized by means of box plots, histograms, means,
medians, the upper and lower quartile points, the SD, and indices
of skewness and kurtosis.
- What to Do:
- Click on the colored title of this on-line resource: "How's
Your Reaction Time."
- After the next screen pops up, click on the "Begin" button
that's located under the heading "Comparing Distributions."
- On the new screen that pops up, read the instructions carefully
and then click on the "Begin" button.
- Continue clicking on the small and large squares until you
see a summary of your reaction time data.
- Sky Huck's Puzzle Question:
Try to perform the reaction-time task such that your scores for
the small squares are positively skewed whereas your scores for
the large squares are negatively skewed.
|
| Stem-and-Leaf
Displays |
- Description:
You'll see a stem-and-leaf display for a real study involving
147 people who had their arm strength measured.
- What to Do:
- Click on the colored title of this on-line resource: "Stem-and-Leaf
Displays."
- After the next screen pops up, read the short paragraph
under the heading "ARM" and then scroll down to examine (1)
descriptive statistics for the amount of force exerted by
the 147 folks who were studied and (2) a stem-and-leaf display
showing each of the 147 scores.
- Be sure to click on the colored term "stem-and-leaf"; this
will give you a two-page explanation of how stem-and-leaf
displays are constructed.
- Sky Huck's Question to You:
Can you correctly answer, on your first try, the multiple-choice
question that appears immediately below the stem-and-leaf display?
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