StopWatch activity

[James Cameron]

On Wed, Nov 14, 2007 at 12:03:08PM -0500, Benjamin M. Schwartz wrote:
> It takes some time to process your mouse click, and under heavier CPU
> load, that time may be long enough that the time label continues to
> redraw before it can be stopped.

Good.  I suspected as such, based on your original announcement, so when
I saw it I didn't dimiss it but tried some more.  Hopefully the kids
will notice as well, and the teacher can have your notes on how to
explain the effect.  ;-)

Please put your post in the source.

> Every digital stopwatch I have ever seen has precision to hundredths
> of a second, no more and no less.

Yes, I suspect they mostly use the same internal design.  You are lucky,
you don't have to.

> I don't know what you mean by a bar graph.  Younger children can't
> read analog clocks (I recall being taught how to read them in second
> grade).  Also, drawing clock faces is computationally expensive.

A bar graph ... okay, perhaps "fuel gauge" might be a better term, ...
creates a linear single axis representation of time, which the human eye
is *very* good at estimating and predicting against.  It is how a kid
catches a ball.

A stopwatch clockface, represents the time by rotation of a marker
around the circumference of a circle.  It does not have the same
"problems" associated with 12-hour analog clocks, since there is
normally only one hand, and the full circle doesn't represent half a
day.

Analog day clocks can be taught to children, but not as easily as
numbers and digital clocks, I agree.  On the other hand, the lack of
momentum perception on a digital clock tends to teach children the art
of estimating time without requiring an external beat.

Analog clocks remain the cheapest clock per square metre of visual
coverage, so our target market will be exposed to them.  You cannot
dismiss them based on your first-world understanding of digital clocks.

-- 
James Cameron    mailto:quozl at us.netrek.org     http://quozl.netrek.org/