Transcript Fair Testing

Presenters:
Maria Barrett & Jodi-Ann Gulley
Science & Engineering Faculty
Queensland University of Technology
(QUT)
Scope
• Fair testing – life skills focus :
– ACARA – Science Inquiry Skills focus (also SHE – not
covered in this session)
– Problem-based learning
– Inquiry-based learning
• Recognises variations between reporting formats –
The ‘scientific method’ is not covered in full in this session
• Session will benefit beginning teachers and those
seeking more information on fair testing as a process
and skill.
What is fair testing?
Fair testing is a way to
find the answer to a
researchable question
and know that the
answer is correct.
It helps us to be sure of
the cause of something.
Fair testing
• Change one thing
• Measure one thing*
• Keep all other things
the same
Doing this means we can tell what causes
the change.
* Measure can also include observe one thing.
Fair testing
• The thing we are changing is called an
independent variable (changed by the
scientist conducting the test)
• The thing we are measuring is called the
dependent variable
– This is because the result depends on the thing we
are changing
• The things kept the same are the controlled
variables
Example 1 Sherbet Fizz
(ACARA Chemical Sciences – Year 6*)
Step 1: the research question
We know that sherbet fizzes when put in our mouth
– but...
What question do we want to answer?
Q: What sherbet ingredients react to
cause the fizzing?
Note: Those teachers who use Primary Connections may have used a variation of
this experiment in the ‘Change Detectives’ unit.
Step 2: the hypothesis
• An educated guess about how things work
• An easy way to remember:
If ......[I do this]....., then .....[this will happen]*.
If I mix [different combinations of sherbet ingredients] with water, then I
can find out which ones cause sherbet to fizz.
• Needs to be worded so that it
can be tested by your experiment
* A ‘because’ statement may be added here to determine student prior
understanding and reasoning, and for development of argumentation skills. A
‘because’ statement is not used in secondary school contexts when writing
hypotheses.
Step 3: test the hypothesis
• How will you answer the question?
• Design and conduct an experiment using fair
testing principles.
• Devise method:
– Mix ingredients together
– Add water
– Watch for fizz
Sherbet testing
• FirstIcing
measure
out
all
the
ingredients
into
the
sugar &
Icing sugar &
Icing sugar &
Icing sugar
testing
tray inbicarb
a logical
order
citric acid
soda
jelly
crystals
– This prevents contamination (using clean, dry
Jelly crystals & Jelly crystals & Jelly crystals
sticks)
citric acid
bicarb soda
– We can compare all results at the same time –
Bicarb soda & Bicarb soda
there
may be some bubbles but only one should
citric acid
fizz up
Citric acid
– Make
sure this includes testing the ingredients on
their own (control)
• Then add the water and watch for fizzing
How do I know I am right?
• Fair testing!
– Test combinations of ingredients
(independent variable)
• Test each ingredient
• Test pairs of ingredients
– Watch for fizz (the dependent variable)
– Keep all other things the same
(controlled variable)
Example 2 WaterWorks
(ACARA Chemical Sciences – Year 7*)
Step 1: the research question
Water filtration is needed to make water safe to
drink. You are supplied with a dirty water sample
and different filter materials.
What research question do you want to answer?
How will you answer the question?
Conduct an experiment
– Select different filtering materials to test
– Fill each column with one of the filter materials
– Pour water sample into column
– Leave to filter through column
– Check ‘clean-ness’ of water
How do I know I am right?
• Fair testing!
– Change one thing at a time
(independent variable – filter material)
– Measure one thing – ‘clean-ness’ of water
after filtering (dependant variable)
– Keep all other things the same – use same
syringe, base water sample, amount of water
filtered*, etc (controlled variables)
* Having to ‘measure’ the sample being filtered or amount of filter
material can cause some confusion for students – this is preparation
measurement NOT the output being measured
Water Filtration
1. Use water from same sample – shake before
pouring to ensure well mixed
2. Measure same quantity (10ml)
3. Pour water into column
4. Repeat 1-3 for other columns (filter materials
are the independent variable)
5. Wait for 5 minutes
6. Check ‘clean-ness’ of water in beaker
(dependent variable)
Example 3 LEGO car design
(ACARA Physical Sciences – Year 7*)
Step 1: the BIG design question
What makes a car go faster?
In this example you are provided with a LEGO
car and a variety of wheels...
What research question do you want to
answer?
How to run a Fair Test - recap
• Remember
– Step 1: What’s the question?
– Step 2: State your hypothesis – a guess about how
things will work
– Step 3: How do I find the answer?
• Design the experiment
– How do I know I am right?
• Change one thing
• Measure (or observe) one thing
• Keep all other things the same
Resources
• Elsie and the Golden Cows:
http://learningplace.com.au/sc/online/Elsie_an
d_the_golden_cows/pirates_v0_04.html
• STAQ website – members only – log-in
required
www.staq.qld.edu.au/programs/primary