1. Scientific
Investigation

2. HOW TO…ask a question that
Step 1：
HOW TO…ask a question that
can be tested?

3. Must be turned into a question that
Scientists are always doing investigations.
They want to find out about things.
An Idea
Must be turned into a question that
can be tested.

4. 1.Flour 250 g 2.Yeast 12.5 g 3.Water 150ml Recipe
This is a recipe for making bread.
Recipe
1.Flour 250 g
2.Yeast g
3.Water 150ml

5. ？
Is it better to add
more yeast
into the dough?
Is this a good question to ask?

6. Will the dough rise higher if more yeast is added?
This question has clearly
stated the quantities
to be measured.
The rise of the dough can be measured.

7. HOW TO…make predictions?
Step 2：
HOW TO…make predictions?

8. Explain the theory behind your predictions.
Making predictions basing on the
science you know.
If more yeast is added, the dough will rise higher.
Explain the theory behind your predictions.

9. Explanation︰ Less yeast More yeast 3 minutes
Yeast in the dough will release a gas.
This makes the dough rise. So the dough
will rise higher when more yeast is added.
Explanation︰
Less yeast
More yeast
3 minutes

10. HOW TO…make complicated predictions?

11. Quite a number of factors will usually affect
the results of an experiment.
Factors that will affect the rise of the dough︰
Amount
of yeast？
Temperature？

12. HOW TO… plan investigations
Step 3：
HOW TO… plan investigations
and fair tests?

13. In planning the experiment, we have to consider：
what factors to change
what factors to keep constant
what factors to observe and measure

14. Experiment 1: The effect of the amount
of yeast on the fermentation of the dough
Factors to change：amount of yeast
Factors to
keep constant : amount of flour, amount of water,
time, temperature...
Factors to observe and measure：the rise
of the dough

15. Experiment 2: the effect of temperature
on the fermentation of the dough
Factors to change：temperature of
fermentation
Factors to
keep constant：
amount of flour, amount of yeast, amount of water, time...
Factors to observe and measure：
the rise of the dough

16. HOW TO…choose the spread of
Step 4：
HOW TO…choose the spread of
your readings?

17. Experiment 1: the effect of the amount
of yeast on the fermentation of the dough
Group A 4 4
Group B 10 10

18. Which spread of readings can provide a more reliable result?
Group A
Group B

19. Group A Height of the dough (cm) Amount of yeast(g)10 8 6 4 2 20 40 60 80
Amount of yeast(g)
When the range of measurement is too small, the data collected will be less reliable.

20. Group B Height of the dough (cm) Amount of yeast (g)10 8 6 4 2 20 40 60 80
Amount of yeast (g)
When the range of the measurement is bigger, the data collected will be more reliable.

21. Step 5：
HOW TO…carry out
the experiment?

22. Apparatus of the experiment︰
yeast
flour
glass
teaspoon
hot water
cold water
ice

23. Procedure: Experiment 1 Experiment 2
The same temperature for fermentation but
different amount of yeast
Experiment 2
The same amount of yeast but
different temperature for fermentation

24. HOW TO…observe and record
Step 6：
HOW TO…observe and record
experimental results

25. Observation and recordings

26. Using other methods to record
experimental results
1minute
After 1 minute,
the dough will...
2 minute

27. Scientific journal I observed： I learnt :
Applications in everyday life：
I want to know more about：

28. Step 7：
HOW TO…draw conclusions
from experimental results?

29. A scientific explanation
My conclusion is...

30. Factors affecting the results Ideas for investigation
Observation
A testable question
Prediction
Factors affecting the results
Ideas for
investigation
Range of measurement
Conducting the experiment
Observation and recording
Drawing conclusions

31. Reflection： Any difficulties met ways to solve the problems
the science involved in solving the problems
conclusions drawn from the experiments
problem-solving skills
experience in cooperation