Scientific Method Grade 3
Name: Carmela B.
Date: Monday, September 30, 2002
How can I introduce the "scientific method" to my third
graders. I want to do a power point presentation and need some suggestions.
I believe the best way is to recreate a situation that traces out naturally
the scientific processes (since there are many). First off, there is NO ONE
"scientific process". There are certain paradigms of science. Observation,
leading to gathering of data (sometimes as just memories)...once the data
make a pattern, by inductive logic, we often come to a certain belief. This
is where modern science, probably starting with Galileo Galilei, (remember
his quote" But I, Simplicio, who have made the test can assure you that...)
steps in. The real mark of science is then to begin controlled careful
experiments that test your belief. All these experiments can do is disprove
the belief...they cannot prove it to be correct. So lets take an example.
Let us duplicate some ancient science...astronomy would be a nice choice.
This gives you a chance as a teacher to discuss how ancient civilizations
were most interested in survival. One of the most important characteristics
of a civilization is to be able to have some sort of agriculture to feed the
populous. To do so they would need to know in what time of the season to
plant and when to harvest and this is where the heavens helped...all of
which depended in part on their understanding the motions of the sun and/or
the stars. Since school is in the day lets choose to observe the sun. One
of the first steps in predicting time and the seasons is to make a "shadow
plot" which is a very ancient simple thing. It requires a straight stick, a
sunny day, an open outside area, a large piece of paper (the ancients just
did it in sand...you could use a sand box if you have one to be authentic!).
In the early morning, place the paper on a flat surface in the sun outside
in an open area and the jam the stick in the ground in the middle of the
paper. At a three or four times a day (the more the better) make a "shadow
mark" where the shadow falls and mark the time of day on the shadow mark. Do
this once a month for about six months. Then lay the papers out and find if
the students can come up with a theory of what is going on. (They should see
that the shadow plots are shifting and some lines are getting longer.) Then
they will need to test their theory somehow. Call me when you get
Peter Faletra Ph.D.
Office of Science
Department of Energy
First, "the scientific method" implies a SINGLE "correct" approach, which
is misleading and incorrect. A better term is "scientific processES" --
plural intended. It is important to point out that the scientific process of
obtaining information and suggesting causes etc. is not some mysterious
stone tablet. It is a way of asking questions. Books have been written on
the subject, and you will find that they do not all agree. The topic and
related topics have been discussed on the NEWTON BBS web site. You can get
some good insights from the GENERAL QUESTIONS archives, particularly 1171,
1178, 1182 and 1184.
The scientific method is essentially a guessing game, and just playing a
good guessing game seems like a reasonable way to teach it. The game we
play at home is "Guess the Animal", and it goes like this:
I am thinking of an animal.
Does it have wings?
Does it have hair?
No does it live in the water?
Does it breath air?
At each point in the solution, you have an idea of the territory in
which the answer might lie, and the territory in which it cannot lie.
Using this information, you try to craft questions whose answers will
eliminate some territory from the range of possible solutions. If you
think you know the answer, you try to craft questions whose answers will
confirm or deny your guess. Here is the most important part: if you
believe you know what the true answer is, and you then get an answer that
eliminates your belief as a possibility, you have to stop believing that
it is the
Things you can point out as the game progresses:
If, for example, birds have been eliminated as a possibility, there is
no point in asking "Does the animal have feathers?" because the only
possible answer is "No.", and this answer does not give you any new
If, for example, you have narrowed the field to four-legged animals,
asking if the animal is a dog is usually not an efficient way to get to the
solution, because the answer usually will not eliminate very much territory -- if
the animal actually is a dog, of course, you win big. But, on average, a question
like "Could it be a pet?" will eliminate more territory than "Is it a dog?".
(The scientific method does not forbid inefficient questions, of course, but
the scientific method is usually thought of as a systematic search for truth,
rather than merely a bunch of wild stabs at it.)
One thing you cannot get across about the scientific method with this game,
is that a question can produce information that is relevant not only to the
game in which it is asked, but also to other possible games. Once you have
established a fact, or a constraint on what might possibly be fact, the
information takes a life of its own. To apply the scientific method
with this information, you need not only the answer itself, but an
understanding of the context in which it is true. I do not know how to
get this across to third graders.
I would suggest taking an example from their daily life. After all, the
scientific method is really just an organized way of figuring something out.
Say, have them imagine that they wake up and when they go in the bathroom
their toothbrush is missing. They make a reasonable assumption (a hypothesis)
-- their kid brother hid it in a drawer. They collect some data-- looking in
the likely places, and then draw a conclusion: Their hypothesis does not have
to be correct; maybe they did not find the toothbrush in the drawers, but
learned something anyway that will help them make a better assumption in the
next go'round. Keep it simple. (Personally, I would just talk about it in a
down-to-earth way, and skip the power point so the message does not get lost
in the presentation, but that is my unsolicited opinion.) Good luck.
Paul Mahoney, PhD
Oh Goodness. DO NOT use power point. Let them play.
Get about 10 different brands of paper towels. Ask them what would make a
good paper towel. They usually come up with stuff like "can hold a lot of
water" "won't tear when you wipe something with it" "Lasts a long time when
you scrub" Have them come up with simple experiments they can perform. Get
them the different paper towels and let them have at it. Of course you are
going to have to help and guide them to make good experiments; and things
that you can easily do in your classroom. Like timing someone using a wet
paper towel to rub on the desk until it gets a hole in it. Do this for each
kind of towel. Devise or help them devise all of these nifty experiments
and DO them. Have them chart their results and as a class look at the
evidence and decide which is the best paper towel.
Then explain to them what they did was scientific method. Coming up with
the hypothesis, making the tests, performing the tests, presenting the
results, interpreting the results. They need to DO this to understand it.
It will take a few days and they will have SO MUCH FUN. Best of all they will
learn Scientific Method a lot better.
Go for it. Be Brave. Let me know how it all turns out.
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Update: June 2012