activity page will offer:
An experience in judging or "calling" the location of a
critical examination of accuracy in judging
minds-on analysis of judging rules
- Work in teams of three. Use colored chalk and a measuring
stick to draw a series of side-by-side chalk lines. Each
line should be about three feet long and about the width
of a tennis ball. Neighboring lines should be filled in
with contrasting colors, making them easy to see and distinguish
one from another.
- Set up a video camera and tripod several feet from the
chalk pattern. The camera's vantage point should offer a
"parallel" view to the line pattern. Zoom in on the lines.
The image captured by the camera should include all of the
- Make a viewing line on the opposite side of the pattern.
This line should be drawn perpendicular to the pattern and
positioned about 20 feet away.
- When you are ready to begin the testing, position each
of the three teammates as follows. The "line judge" stands
at the viewing line. The videographer works the camcorder.
The "dropper" stands immediately to the side of the line
- The dropper holds a tennis ball at shoulder height above
the pattern. He or she releases the ball so that it falls
and strikes any of the pattern's colored lines.
- The judge observes, identifies and records the line that
has been struck. The videographer makes sure that the image
has been captured on videotape.
- Perform nine more ball drops.
- When the drop sequence is completed, the whole team reviews
both the videotaped falls and the record maintained by the
judge. How do they compare?
- Exchange roles so that all students have experience in
each of the tasks.
- Once this round is finished, double the judging distance
to the drop zone and repeat the experiment.
- What factors affect a judge's accuracy?
- How did the accuracy of the judge's calls compare with
the videotaped record?
- What happened to the judge's accuracy when the distance
to the ball drop was doubled?
- Were there differences among the records of the three
judges? If so, what might be the possible causes for these
A Different Slant
the line judge had a perpendicular vantage point to the chalked
area. Would this affect the accuracy of the calls? Why or
why not? With your instructor's approval, develop a method
of inquiry that would uncover how a person's vantage point
affects what they see and perceive.
Imagine that a judge's dubious call is critical to the outcome
of a game. Is the player out or safe? Should a taped record
that clearly shows the event be used to reverse a judge's
call? Why or why not?
With your instructor's and your parents' permission, set up
a camcorder and tripod behind the protective cage that surrounds
home plate. Focus in on both the pitcher and catcher. Use
a high-speed shutter to capture this fast-moving action. Record
a series of thrown pitches. At what point of the ball's movement
can you judge the throw as a strike or ball? How far must
the ball travel before you can accurately predict its destination?
Be sure to wear a helmet when performing this activity.
With your instructor's approval, create a transcript of a
fictional court case. The defendant is an umpire who is accused
by a ballplayer of making an error in judgement. The prosecution
bases its case upon a taped record of the incident. Select
other students to play the umpire, a witness and the prosecutor,
and perform this work as a classroom play.
Here's a primer on assuming the role of umpire in baseball.
electronic umpires replace the human kind?
more Web links on this topic - visit our Resources
activities in this guide were contributed by Michael DiSpezio,
a Massachusetts-based science writer and author of "Critical
Thinking Puzzles" and "Awesome Experiments in Light & Sound"
(Sterling Publishing Co., NY).
Academic Advisors for this Guide:
Corrine Lowen, Science Department, Wayland Public Schools,
Suzanne Panico, Science Teacher Mentor, Cambridge Public Schools,
Anne E. Jones, Science Department, Wayland Middle School,