This document outlines the key components of an experimental design for teaching students, including background research, aim, hypothesis, equipment, variables, results, discussion, and conclusion. It explains that an experiment tests a hypothesis by manipulating an independent variable and measuring its effects on a dependent variable while controlling other influences. Replication, validity, and reliability are also discussed.

1. Teaching experimental
design
Year 7 Integrated Curriculum

2. What is an “experiment”?
• In school, “experiment” is often used
to describe hands-on experiences

3. What actually is an
“experiment”?
• A science experiment tests a
hypothesis

4. Components of an
experiment
• Background research
• Aim
• Hypothesis
• Equipment
• Types of variables
• Results
• Discussion
• Conclusion

5. Background research
• Every experiment starts with a topic
of interest (Eg. What are the effects
of ocean acidification on living
things?)
• Background research finds out what
we already know about the topic

6. Aim
• Always starts with “To”
• Tells the reader what the
experiment aims to do
• Eg. To find out how
ocean acidification
affects the shells of living
things

7. Hypothesis
• A prediction of the results based on
the background research
• Example – The more acidic the
ocean is, the quicker the shells of
ocean invertebrates will dissolve
If A happens then B will happen

8. Equipment and Method
• List the equipment used in
the experiment
• Method lists how to do the
experiment in steps
• Always starts with a verb
• Accompanied by a
scientific diagram where
appropriate

9. Types of variables
• Independent variable – What we change on purpose (Eg.
how acidic the water is)
• Dependent variable – What we measure as the result
(Eg. How much shells have dissolved after 3 days)
• Controlled variables – What we keep the same to keep
the experiment fair (Eg. The amount of acids and water;
the type of shell; the temperature of the environment)
• In most experiments there is ONE independent
variable, ONE dependent variable and many controlled
variables

10. Types of variables -
Strategies
• Cows Moo Softly
– Change one thing
– Measure one thing
– Keep everything else the same

11. Controlled variables vs
control
3M HCl with 2M HCl with 1M HCl with Water with
shell shell shell shell
•Independent variable - concentration of acid
•Dependent variable – how much each shell dissolves
•Controlled variables – time of experiment, amount of
acid and water, type of shell
•Control – the water with shell

12. Validity and reliability
• Validity – Is the experiment testing
what you intend to test?
• Reliability – Are these results a
fluke? If I repeated the experiment
again, will I get the same results?

13. Replication
• You shouldn’t just have
one beaker of 3M acid, one
beaker of 2M acid, etc.
• You need 5 beakers of
each acid so that there is
replication.
• Replication increases
reliability.
• You’ll need to use average
calculations.

14. Results
• A table and graph must be
done
• A graph shows patterns
that cannot be seen easily
in a table
• It’s usually a choice
between a column graph
or a line graph
• X-axis = independent
variable
• Y-axis = dependent
variable

15. Discussion – analysis of
results
• What do the results mean?
• Are the results expected? Are
there any usual results?
• What were some possible
sources error?
• How can the experiment be
improved?
• What are some other
experiments to do in the
future?

16. Conclusion
• The aim written in past tense and
says whether the hypothesis is
correct
• Eg. The effects of ocean acidification
on shells were determined. The
more acidic the water, the faster
shells dissolve. The hypothesis was
correct.