Transcript Acc_Bio_Scientific_Method

The Scientific Method
Everyone uses the
Scientific Method
everyday.
Yes, Even
You!
The Scientific Method
Our – Observe
Pizza – Problem
Has – Hypothesis
Extra – Experiment
Delicious – Data
Cheese – Conclusion
The Scientific Method
Definition – An organized and systematic approach to
studying the world and solving problems.
Observation – Using your senses to study the world.
Problem – Asking a narrow question based on specific
observations.
Hypothesis – Educated guess to answer the problem.
Expressed as an “If . . . , then . . .” statement.
The Scientific Method
Experiment – A test of your hypothesis.
* You are trying to prove your hypothesis wrong!
Scientists use experiments to search for cause
and effect relationships in nature. In other words, they
design an experiment so that changes to one item
cause something else to vary in a predictable way.
The Scientific Method
Variable –
Independent variable - variable that is changed by
the scientist. There is usually only one independent
variable. (The Cause)
Dependent variable - changes in response to the
independent variable. The data that is collected from
the experiment. (The Effect)
Control Group - does not receive the variable
The Scientific Method
Constants – Things that are the same for both the
experimental and control groups. There can be multiple
constants.
Controlled Experiment
Experimental Group - receives the treatment
Control Group - does not receive treatment
Experimental Group
• 10 plants
• 20 mL of water a day
• 5 g of fertilizer
• 8 hours of sun a day
Control Group
• 10 plants
• 20 mL of water a day
• 0 g of fertilizer
• 8 hours of sun a day
The Scientific Method
Data – Information you collect during an experiment.
Conclusion – A summary of your experiment.
States: “The data supported (or did not support) the
hypothesis.”
States possible errors effecting the outcome.
The Scientific Method
How do we make the results more reliable?
Increase the sample size!
Consider this . . .
• Aidan Dwyer did a much better job on his 7th grade science
project than any of us. While on a wintertime hike in the
Catskills, he noticed the branches of trees held a spiral
pattern as they ascended. He wondered if that could possibly
serve some purpose, looked into it, and learned about the
Fibonacci sequence, which is a mathematical way of describing
a spiral. Then he studied tree branches more closely and
found their leaves adhered to the sequence. Then he figured
out that if he arranged solar panels the way an oak tree
arranged its leaves, they were 20 to 50 percent more efficient
than the standard straight-line solar arrays. That is why the
American Museum of Natural History gave him a Young
Naturalist award, and published his findings on its website.
Consider this . . .
• His write-up concludes: The tree design takes up less room
than flat-panel arrays and works in spots that don't have a full
southern view. It collects more sunlight in winter. Shade and
bad weather like snow don't hurt it because the panels are not
flat. It even looks nicer because it looks like a tree. A design
like this may work better in urban areas where space and direct
sunlight can be hard to find.
• Not bad for a kid who hasn't started high school yet.
The Scientific Method
Are wrong answers “bad?”
Can we learn anything
from “wrong” answers?
Is there always a final or
definitive answer?
Are we done studying a
problem once an
experiment is finished?