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4:00 - 4:05 PM
Welcome
4:05 - 4:15 PM
Starter on Fair test
4:15 - 5:30 PM
Fair test
5:30 - 6:00 PM
Can we implement the fair test in students’
exams?
6:00 - 6:15 PM
Prayer Break
6:15 - 7:15 PM
How can you help your students to fair test?
7:15 - 7: 30 PM Survey and Feed back
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Ahmed and Ali are investigating how electrical
resistance of wires changes with length. Unfortunately
both of them let the current get too high for shorter
wires, which increases the temperature drastically.
Since temperature affects resistance (in addition to the
length), it is not a fair test.
Think:
1. What are the mistakes students did it in this
experiment?
2. What could we do to make it good experiment (fair
test)
3. Identify the independent and dependent variables in
their investigation.
How Science
Works
Conducting a Fair
Test
What is a Fair Test?
“A fair test is where you ensure that results are due to the effect of
the independent variable on the dependent
variable and to no other factors.”
“You achieve this by ensuring that all the variables
other than the independent variable are
kept constant or controlled.”
An investigation where only one factor is
changed while all others are kept the same
(controlled).
This way, the changes are due only to the
thing we want to test
e.g. if testing the effect of amount of light on
growth of seedlings, keep everything else
the same e.g. type of soil, amount of water,
temperature, length of time grown etc.

The things that can change in an experiment
are called variables.
e.g. in the seedling experiment, variables were
amount of light, amount of water,
temperature, soil type….
There are different types of variables in an
investigation:
 Independent variable: (What I change)
the thing that is changed on purpose


Dependent variable: (What I observe /
measure) the thing that is measured
Controlled variables: (What I keep the same)
all other changeable factors that must be
kept the same to ensure a fair test
Example
The following apparatus is used to
investigate the effect of glucose
concentration on the rate of yeast
respiration.
Glucose concentration is the
independent variable, and
the volume of gas produced is the
dependent variable...
Identifying Control Variables
Identify the control variables that you would need to keep constant during the
experiment, to ensure a fair test.
Move on to the next slide to show the variables…
Identifying Control Variables
“To be sure that changes in the volume of carbon dioxide
produced are due to changes in glucose concentrations, you
would have to ensure that the following
control variables were kept constant…”

The volume of glucose solution

The mass of yeast

The temperature of the reactants

The age and species of the yeast
Identifying a Fair Test
For these investigations, identify the experiment which would give a fair
test…
Can we
implement
the fair test
in
students’ exams?!!
Test B, 5a Bean seeds
In this question Aisha has described how
she will make an investigation fair.
Pupils need a good understanding of why
a test needs to be fair in order to
recognise and explain if the factors are
important or not.
In part 5b, most pupils recognised that
the colour of the watering can doesn’t
matter.
However, in this part, 5a, pupils have
more difficulty recognising why using the
same type of soil is important.
Level 3
Sc1/2d
A.
One type of soil could be rocky and the other plain mud with toxins
B.
Because she is using the same thing on everything
C.
Because she should only change the type of bean seed she grows
D.
Some soil might have more nutrients than a different type of soil
E.
Because you need to make it fair in a test
F.
If she uses different soils, one might be better than another
G.
If you use different types of soil the beans might grow quicker or slower
H.
Some seeds may only grow in a certain soil
I.
Some soils have less pH than others
J.
If you use a different soil you won’t get a fair test
K.
She is trying to find out which seed germinates more quickly, not the
best soil
B, E, J = Wrong A, D, F, I = Allowable C, G, H K = Correct
Test B, 9b Making
bread
In this question
pupils are given all
the variables in a
test.
They are required to
identify which ones
should be kept the
same in each
mixture, and which is
the variable being
changed.
Level 4
Sc1/2d
© Qualifications and Curriculum
Authority, 2006.
Test B, 9b Making
bread
In this question
pupils are given all
the variables in a
test.
They are required to
identify which ones
should be kept the
same in each
mixture, and which is
the variable being
changed.
Level 4
Sc1/2d
© Qualifications and Curriculum
Authority, 2006.
Generate Ideas
Change
Measure/observe
Which
variable
might
affect…
What will
be our
evidence?
Let’s make a question
The variable I will change is..
The variable I will
measure/observe is
c
m
These variables I will keep the same
c
c
c
c
c
c
Making a prediction
What will happen to
the
when I
I think that…
because…
m
c
How much data do I need?
How many
I will have
c
I will take
m
Why might you want to measure/observe
what happens more than once?
To make your
data
more reliable
Table of Results
c
change
m
Table of Results
change
c
m
*
Tables
When you draw up a table of your
results,
the independent variable goes in the
first column, like this:
If you take several readings of
the dependent variable, then
you can calculate the mean (average)
Then your results will be more reliable.
Making a graph
m
c
Interpreting graphs
m
c
Key questions
•Which is the highest reading?
•Which is the lowest reading?
•Do all the readings increase?
•Are there any unusual readings?
Drawing conclusions
When I
What happened to
c
m
Key Questions
•What happened and why?
•Is this what I thought would happen?
•Has this proved or disproved a some of my
scientific understanding?

Take a simple context such as bouncing a ball, or
dissolving some sugar in water.




Which factors are suitable for being measured (the
dependent variable)?
Are there any variables that are irrelevant and
unlikely to affect the outcome of the investigation?
Out of the remaining variables, only one should
be changed in an investigation (the independent
variable) and all the others should be kept the same.
Write down a question using these variables that
you could investigate.
Type of ball
Height from which ball is dropped
Surface on which ball is dropped
How high the ball bounces
How the ball is dropped
Number of times the ball bounces
How long the ball continues to bounce
Weight of ball
Size of ball
Indoors or outside
How many times will a ball bounce on different surfaces?
dependent variable
independent variable
Which of the variables need to be kept the same for this investigation?
Amount of sugar
Type of sugar
Size of beaker
How long it takes to dissolve
Amount of water
Stirring the mixture
Temperature of water
Type of liquid
Material of beak
Thermometer
How long will it take to dissolve different types of sugar?
dependent variable
independent variable
Which of the variables need to be kept the same in this
investigation?
Biology:
•Investigate the tar content of different brands of
cigarette.
•Investigate the effect of concentrations of sulfur
dioxide on growing plants.
•Investigate the effect of exercise on the heart
rates of people’s size.
•Investigate the rate of osmosis between solutions
of different concentration.
•Investigate the effect of concentrations of sulfur
dioxide on growing plants.
Physics
•Do investigation to show that the time taken by
an object to drop is independent of its mass under
conditions of negligible air resistance.
•Do investigation to measure the power output of
a muscle under varying conditions.
•Do investigation to compare the insulating
properties of different roof materials and
structures.
•Do investigation to study the factors effecting on
the resistance of a wire
Chemistry:
•Investigate the effect of factors affecting
rates of reaction.
•Do investigation to compare the energy
output from a blue and a yellow Bunsen
flame.
Do science investigation in your
classroom.
 Bring the daily lesson plan.
 Evidence of students work.
 The reflection on your lesson.

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