Experimental Design
Hypotheses
Objectives
• Become proficient at writing problem
statements, hypotheses, and experimental
procedures.
• Identify independent variable, dependent
variables, and controls when exposed to a
scientific experiment.
• Describe the correct way to gather data in an
experiment.
The Plan
• You need your Super Volcano lab.
• We will be taking some notes, going over some
examples, and filling out our lab sheet.
1. Write/analyze problem statements.
2. Write hypotheses.
What is the problem statement of our super
volcano lab?
First Example
• This first video is the basis of
the myth tested by the
mythbusters.
First Example
• Now we’re going to watch a
clip of the episode of
Mythbusters in which they test
the Lego myth.
• Listen and write their for their
problem statement(s).
#1
#2
Problem Statements
• What we’re the problem statements?
▫ Does a lego ball this size require 5 million pieces?
▫ Is a lego ball this size easily moved around?
▫ Will a ball bounce off a car?
Problem Statements
• A problem statement is a question statement
that identifies what needs to be solved. Problem
statements are formed as questions because
they are identifying something that needs an
answer. A problem statement should be
specific so that anyone reading or hearing it
knows exactly what needs to be measured to
answer the question.
Words to Use and Avoid
(for problem
statements and hypotheses)
• Words to use to help generate measurable data:
▫ “higher number”
▫ “increase in…population, rate, etc”
▫ “decrease in…”
• Words to avoid (will not generate measurable data):
▫
▫
▫
▫
▫
▫
“longer”
“better”
“faster”
“more effective”
“best”
general words that do not identify specifically what is
being talked about, such as “it”
Hypothesis
• What is a hypothesis?
• A hypothesis statement is:
▫ A proposed answer to a problem.
▫ Based on observations.
▫ Testable (must be able to measure what is being
tested).
• Do not define a hypothesis as:
▫ An “educated guess”
▫ An “if-then” statement
Hypotheses
• If a hypothesis is a PROPOSED answer to a
problem, you cannot be afraid to be incorrect.
"It is very unnerving to be proven wrong,
particularly when you are really right and the
person who is really wrong is proving you wrong
and proving himself, wrongly, right."
-Lemony Snicket
Things That Have Been Wrong
Science that has changed:
• There are nine planets in our solar system.
Things That Have Been Wrong
Science that has changed :
• There are 109 elements.
Things That Have Been Wrong
Science that has changed:
• Maggots “arise” from decaying meat.
Things That Have Been Wrong
• “Television won’t last. It’s a flash in the pan.”
— Mary Somerville, pioneer of radio educational broadcasts, 1948.
Things That Have Been Wrong
• “Heavier than air flying machines are
impossible.”
— New York Times, 1936
Things That Have Been Wrong
• "Everything that can be invented, has been
invented."
-- Charles H. Duell, Commissioner, U.S. Office of Patents, 1899.
Writing Hypothesis
• NEVER USE, “I think” in a hypothesis.
• The reader knows it’s you…you wrote it.
Objectives
• Become proficient at writing problem
statements, hypotheses, and experimental
procedures.
• Identify independent variable, dependent
variables, and controls when exposed to a
scientific experiment.
• Describe the correct way to gather data in an
experiment.
First Example – Writing a Hypothesis
Second Example – You Try!
Let’s work on the worksheet!
Second Example – You Try!
Let’s work on the worksheet!
First Example
• Now we’re going to watch a
clip of the episode of
Mythbusters in which they test
the Lego myth.
• Listen and write their for their
problem statement(s).
#1
#2
Closure and Summary
Summary
What three things must all
problem statements be?
Please write in a complete
sentence!
Homework
Problem Statement and
Hypothesis WS