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Learning
Objectives The
student will be able to:
1.
demonstrate the ability
to make detailed observations and formulate questions based on those observations.
2. use the scientific method to conduct a scientific
investigation which includes the formultation of a hypothesis,
an experiment with the collection
of data, the interpretation of results
attained and the presentation of a conclusion.
3.
understand that scientific
investigations sometimes result in unexpected findings that
lead to new questions and more investigations. |
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Laboratory
Description
During this two-part lab, students will practice the skills
important in the study of science. Students will sharpen their
observation skills, learning to note important details and
ask questions as they observe. They will practice the steps
of the scientific method as they develop experiments on paper,
allowing them the freedom to develop creative, complex experiments
without limits such as money, equipment or time.
The framework used during this process will give students
the tools necessary to ask questions and design future experiments.
Students will learn about the factors involved in the scientific
method as they perform experiments in class. Finally, students
will work in teams to observe an animal, ask questions, conduct
and design an experiment, then report the results.
The Scientific Process
Science is not an already existing set of facts to memorize,
but an ongoing process of discovery that everyone can contribute
to. The following steps of the scientific method can be used
as guidelines during the experimental process.
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Practice
Makes Perfect
We
use the scientific method to answer questions and make
choices every day. Will my indoor plant grow larger if
I move it to a sunnier window? This simple question is
an experiment, without a written plan or results. If you
ask a question and make a measurable change, an experiment
is in progress. Follow these suggestions to turn ordinary
observations and questions into experiments!
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Observation
Begin with a period of observation. Carefully
note details about the behavior and characteristics of the
subject. These will help raise questions and provide useful
information as you design and carry out your experiment. Do
any research necessary to learn more about your subject.
Question
Ask questions as you observe. For example, “Do
roly-poly bugs like to be in the light or dark?”
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1.
Observe everyday objects.
Practice your observation skills. Carefully
describe your favorite objects or new encounters in a journal.
Be sure to include as many details as possible and include
a drawing. Ask questions about the things you see.
2. Make an experimental plan.
Choose one of your favorite questions and
plan an experiment using the format you received in class.
List the materials you’ll need and the steps necessary
in making the experiment work.
3. Try your own experiment!
When possible, carry out the experiment you
plan. Form your own conclusion and list any other questions
raised during the experiment. |
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Hypothesis
Choose the question that interests you most. Predict what
you think the answer to your question will be. I think
that the roly-polies will choose light over dark.
The hypothesis must be measurable. Roly-polies are afraid
of the dark would not be measurable. In the first statement,
we will count the number of roly-polies on the lighted side
of the container after a set amount of time.
It is important that there be only one difference between
the control and the experimental setup. If more than one variable
is changed it is difficult to determine which change caused
the response. When testing whether the roly-polies prefer
light over dark, it is important that everything else is the
same – substrate, dampness, temperature and food sources.
The variable that is purposefully changed is the independent
variable. In the case of our roly-polies, the independent
variable is light. We will add a light to one end of a
container.
The variable that responds in the experiment is called the
dependent variable. We will count the number of roly-polies
that move to the lighted end.
Think about how your independent variable will affect your
dependent variable. Fill in the blanks below when stating
your hypothesis:
If the ( independent variable ) is ( describe how you changed
it ), then the ( dependent variable ) will ( describe the
effect ).
If a light is provided, then a greater number of roly-polies
will move to the lighted side (choose light over dark).
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Methods
Make a detailed list that includes the materials
needed to carry out your experiment and a step-by-step procedure
in a numbered list similar to a recipe. What will you measure
or count? If you have not planned to measure or count something,
you must change your design (an experiment must be measurable).
What will you use as a control? A control
is a part of the experiment that is used as a standard of
comparison. In an experiment, it is used to detect “hidden
variables” that are varying when they should not. In
the roly-poly experiment, we would set up the control and
experimental groups exactly the same, then add a light to
the experimental group.
How many trials will you run? Replicates
show that the results reflect the truth and are not simply
a coincidence. Small changes in environmental conditions can
make a difference in your results. Despite your best efforts,
your sand may be wetter or drier than the previous trial.
Behavior of individuals may vary and impact the results. The
more times an experiment is repeated, the higher the confidence
that the experiment’s results are reliable. By repeating
the trials and averaging the results, chance errors can be
balanced out. Decide on the number of replicates before beginning
the experiment – if not, it is easy to repeat until the
results reflect the original hypothesis!
Experiment
Carry out your experiment! Give the roly-polies
a choice between light and dark. Do this several times.
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Further
explorations
Do you need some ideas for experiments to try?
The following resources are available for use in the
Environmental Learning Lab.
Creepy Crawlies and the Scientific Method by
Sally Stenhouse, 1993. Fulcrum Publishing. Learn how
to use a full spectrum of insects and other crawling
creatures to teach the five steps of the scientific
method.
Classroom Creature Culture. A collection of
articles from NSTA’s journals. Ever wonder how
to care for the frogs, insects and other animals brought
into your home? This book has instructions for collecting,
caring for and investigating simple plants and animals
in your home.
Environmental Science High School Science Fair
Experiments by Steven Dashefsky, 1994. TAB Books.
Everything you need to create your own science project.
Covers a wide variety of topics including soil, aquatic
ecosystems, energy and deforestation.
CD-ROMs
Operation Watershed. Can you solve the web
of environmental problems that are polluting the watershed
surrounding a small community? This mission is designed
to enhance critical thinking and decision-making skills.
Science Sleuths. Try out four different mysteries,
each with six levels of difficulty. Each mystery is
designed to test the research and analytical skills
of students.
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Results
State
the results using detailed notes taken during the experiment,
including any measurements recorded. How can you show your
results in a graph? State exactly how the roly-polies reacted
and which side it chose. If multiple bugs were used, how many
chose light? dark?
Conclusion
State
whether your prediction was confirmed or not and try to explain
your results. Scientists do not say their hypothesis was right
or wrong when reporting their conclusions. Each experiment
provides evidence that a hypothesis is supported or not supported.
Many experiments must be conducted before results are accepted
as fact. Were any other questions raised by your experiment?
Don’t worry if your conclusion proves your hypothesis
false. Science involves trial and error – trying, failing
and trying again. Science does not provide all the answers.
Thomas Edison tried thousands of experiments as he attempted
to make the incandescent light bulb work. When asked if was
discouraged with his results, he replied, “Results! Why,
I have gotten a lot of results. I know several thousand things
that won’t work.” |
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