The Formal Laboratory Report
The general layout for a formal laboratory report will have the following headings in order:
Title
Background Information
Aim
Hypothesis
Apparatus and Materials
Safety
Method
Results
Discussion
Evaluation
Conclusion
See the following pages for an example.
Red words are headings that are to be used as a guide, but are not to be included in the final report.
Blue words are examples of each section.
TITLE OF EXTENDED PRACTICAL INVESTIGATION
Example: Investigating Friction
Background Information:
Provide known scientific information that is the basis for your experiment. Discuss the theories behind your investigation to provide a context for the work you are about to conduct. You do this by conducting research using the Internet, text books, journals or scientific experts.
Example: Friction is a force that opposes motion. Different surfaces provide different levels of friction due to ...
Aim:
Clearly and concisely state what is the purpose of the experiment. It should be 1-2 sentences maximum.
Example: To investigate the effect of mass on the friction force when a block of wood is dragged across a table. (The aim must include the independent and the dependent variable).
Hypothesis:
This is a statement of a possible outcome. Your hypothesis is based on an educated guess. It must be able to be tested in an experiment. This must be supported by scientific reasoning.
Example: The greater the mass on top of the wood, the greater the friction force will be.(The hypothesis statement must include the independent and the dependent variable).
Apparatus & Materials:
List the resources used to carry out the experiment including quantities (volume, mass, length, etc)
Example: 10 cm square block of soft wood (pine) with metal hook attached to one edge, 50 cm approx string, spring balance (5 N maximum), 20 50 g masses, masking tape, metre ruler, stopwatch.
Safety
Think about what the safety risks might be in your experiment. Identify safety measures you could take to make the experiment safer. You should discuss this with your teacher.
Example: There are no specific safety concerns with this experiment.
Method:
Variables
Independent variable: (What were you changing?)
Independent variable: The amount of mass placed on top of the wood block
Dependent variable (What were you measuring?)
Dependent variable: The size of the friction force.
Controlled variables (What variables did you have to keep the same for a fair test?)
The speed the block was dragged, the size of the block, the temperature of the surfaces.
Control Sample (if applicable)
Describing your method (step-by-step)
Describe, in a logical sequence, how you will perform your experiment in enough detail that it could be repeated by another experimenter. They must be numbered steps, beginning with a verb.
1. Attach a wooden block measuring 10cm square with a hook to a force gauge using string.
2. Record the mass of the entire block and hook.
3. Mark a set distance of 80cm.
4. Drag the wooden block with the hook so that it takes 3 seconds to travel the distance, thus keeping the speed the same.
5. Measure the average force from the spring balance, measuring about the middle of the journey.
6. Repeat steps 4-5 5 times and calculate and record the average obtained.
7. Add another 10cm square wooden block to the hook, so that there are now 2 wooden blocks.
8. Repeat steps 2, 4, 5 and 6.
9. Add another 10cm square wooden block to the hook, so that there are now 2 wooden blocks.
10. Repeat steps 2, 4, 5 and 6, for up to 4, 5 and 6 wooden blocks.
Diagram/photograph
Finally, draw a diagram that sums up your design at a glance. Your diagram/photo must be;
· Two dimensional
· Main features labelled
· Drawn in pencil with a ruler (unless computer generated)
Results:
Force (N)Total mass (g) / 1 / 2 / 3 / 4 / 5 / Av
200 / 0.8 / 0.8 / 0.9 / 0.9 / 0.7 / 0.82
250 / 1.2 / 0.9 / 1.2 / 1 / 1 / 1.06
300 / 1.2 / 1.2 / 1.2 / 1.4 / 1.3 / 1.26
350 / 1.6 / 1.5 / 1.7 / 1.7 / 1.6 / 1.62
400 / 2 / 2 / 1.9 / 2.1 / 1.9 / 1.98
450 / 2.2 / 2.3 / 2.3 / 2.4 / 2.2 / 2.28
1. Table of results
2. Calculations
You might need to do some calculations from your data.
In this example, an average was calculated. Show all workings. Even show how you calculated the average!
3. Graph
A graph is almost always the best and clearest way of presenting your results. In general, your graph should have the following:
· Title
· Axes labels
· Units
· Correct scale
4. Observations
List any relevant observations
for later discussion
Discussion:
This is the most important part of your report!
What
Describe the general trends/ patterns in your results
In general, the size of the friction force increased with increased mass on top of the block... Refer to and discuss your results!!!
Why
Suggest some reasons WHY you got these trends. You do not have to be exactly right, just credible.
The added masses on top of the block pushed the two surfaces together more tightly and this is what increased the friction force. Link to the information you gave in your scientific background section. Use information from further research.
Evaluation:
Evaluate
Evaluate the reliability of your data
Did you collect enough data/repeat the experiment enough times to consider your results to be reliable? Were repeated results similar to each other?
Evaluate the accuracy of your data
Was well do your results fit with any published results or trends already known by scientists? How well did the equipment you used help you to get the data you needed? Would there be a better piece of equipment for this experiment?
Identify and explain two strengths of your experimental design.
One benefit of the design was having the two marks on the table to help me keep a constant speed for each trial. By doing each mass 5 times, I was able to obtain a fairly accurate average.
Suggest two improvements and explain how they might have improved your design.
The tape on the bench marking the start and stop caused the block to bump and get stuck a little. It would have been better using whiteboard marker.
The string was too short and pulling it along caused it to pull up a little. It would have been better a little longer.
Evaluate the validity of your method
Did the method allow you to collect relevant data to test your hypothesis. Summarise what was good about your method or what could be improved.
Further
Having done your experiment, what further ideas did it inspire you to investigate?
It would be interesting to try different types of surfaces to try and find the two that generate the least friction force. It would also be interesting to investigate the effect of water on the surfaces and see which have more friction when wet. This could relate to car tyres and road surfaces.
Conclusion:
Say whether the hypothesis was supported or rejected. Answer the aim – be specific.
The aim of the experiment was achieved so that the effect of mass on the friction force when a block of wood is dragged across a table was able to be investigated.The hypothesis is generally supported, the friction force increased with added mass.
DO NOT WRITE: “I had fun and learnt a lot from this” or “I think….”
How to Write an EPI Report Page 6 of 6