Identifying Variables Notes:
Learning Objective: Identify the different parts (variables) of an experiment.
● Hypothesis – ___________________________ / Claim
o If….Then… (Cause and Effect)
o How to write a hypothesis:
1. Find the problem.
2. Identify the part of the problem you can manipulate or would cause something to
happen.
3. Identify the part of the problem that will be affected by the change.
4. Make a statement using prior knowledge!
Hypothesis Practice
If I take time to study every day,
will I make an A in Biology?
Will there be more bacteria in the
warmer or cooler temperatures?
Identify the part of the problem
you can manipulate or would
cause something to happen.
Identify the part of the problem
that will be affected by the
change.
● Experimental Design:
o Experiment – performing a trial or an event to collect support to test a hypothesis.
Variables we need to consider:
●
Independent variable (IV) = ________________________
o
●
Manipulated Variable (MV)
Dependent variable (DV) = ________________________
o
Responding Variable (RV)
not being tested on
●
Control group (C) = _____________________ subjects
●
Experimental group (E) = Test subjects that
●
Controlled Variables or Constants (CV) = Parts of the experiment need to stay the
are
being tested on
_________________________.
Note: Not every experiment has a control group, but will have constants Example: Which ice cream flavor do students
prefer?
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Practice Identifying Variables:
●
In the experiment testing the effect of loud noises on a person’s reaction time. Sarah uses different volumes of
a particular song when testing the time, it takes a person to catch a falling ruler.
●
o
Independent variable: _____________________________
o
Dependent variable: _____________________________
o
Experimental group: _______________________________
o
Control group: _________________________________
o
Controlled Variables (constants): __________________________________________________________
A group of middle school students was given a short course in speed-reading. The instructor was curious if a
reward would influence performance on a reading test taken at the end of the course. Half the students were
offered $5 for obtaining a certain level of performance on the test, the other half were not offered money.
o
Independent variable: _____________________________
o
Dependent variable: _____________________________
o
Experimental group: _______________________________
o
Control group: ________________________________
o
Controlled Variables (constants): __________________________________________________________
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