Learning how to write a good lab
report is like learning to ride a bike. Once youíve figured it out,
you can do it over and over again.
lab reports is very important in IB as they make out a big part of your final
in the science subjects. The key to
writing a good lab report is to find out what is asked for and
include all those parts in your
report. Here are some steps to follow:
should give the aim
of the investigation. It should be clear and concise. If the teacher states
the aim you shouldnít just copy that down, you need to change it to get a full
need to write the
prediction of the investigation. The hypothesis needs to be
very clear, giving an exact and complete description of what might happen (and
why). The prediction is written like: If ÖthenÖ
You can also
give a general
background to the study if you feel like itís
relevant and necessary.
should present the different variables.
The independent variable
is the one that you alter throughout your experiment. For an example, if you
investigate the effect of temperature on yeast fermentation, then the
different temperatures that you use are the independent variable.
The dependent variable
is the variable that you measure. Using the yeast example, the dependent
variable would be the amount of CO2 produced by the yeast (this
shows how well the fermentation is going).
The controlled variables
are the ones that you try to keep constant
throughout your experiment so that they donít affect your experiment. If
investigating the effect of temperature in yeast fermentation, the controlled
variables would be the amount of yeast and water, the time for fermentation,
First give a
list of all the
equipment used in the experiment. Give the size
of beakers/measuring cylinders, etc, used, give the names of any chemicals
that are used in the experiment.
You can use a
(picture) to show the experimental set up if you find it necessary.
Now you should
describe the method.
It should be written in past tense (i.e. not written as a guide on how to
carry out the experiment again, but rather, how you did it). The steps in the
experiment are either self-evident or explained.
In this part
you should explain the different variables. Write
how the independent variable was
Using the yeast example, the independent variable can be
varied by placing the fermentation tubes in hot water baths of different
how changes of the dependent
variable were monitored. You should write how you got your results, e.g.
by reading from the scale on the fermentation tube to see how much CO2
that has been produced.
how the controlled variables
Using the yeast example, you write that you made sure
that the amount of yeast used in each fermentation tube was the same (because
you used a scale), that you used a watch to make sure that the time that the
tubes were allowed to ferment was the same for all tubes.
Write how you
made sure that the
sufficient relevant data was recorded. Describe
the method for data collection, i.e. if you had several trials, if you used
controls, methods of measurements, if your calculations are correct, etc.
your raw data in tables. The tables should be numbered and have captions in
which you briefly describe the contents of the tables and how you recorded the
results. Titles, units and the uncertainty should be given in the headings of
table you can briefly describe the results. You can describe the main
trends and account for any anomalous result. You donít have to discuss the
significance of the results to the aim of the investigation.
Data Processing and
should be processed (calculated) correctly and presented in tables (as above)
and graphs. If you use graphs, they should have a caption in which you
describe the contents of the graph. The axes of the graphs have to be labelled
with units and the points have to be plotted correctly. Make sure that you use
the correct type of graphs. If both variables are continuous, use a
For HL: Error analysis
should be carried out if possible (calculate the percentage uncertainty, etc).
conclusion you should discuss the results you obtained in relation with your
hypothesis. Write a conclusion based on an interpretation of the gathered
results with literature values if possible.
evaluation you should evaluate the method used. Write about the main weakness
of the method used and the weakness in the method of manipulation of data.
the source of error, but donít include personal mistakes.
improvements (that can be carried out in the school lab) to the investigation.
further investigations that are of interest and can be carried out and new
questions that could be posed.
by: IB Genius