Example of a scientific report
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Science experiments need to be done properly and reported following the
scientific format.
Check out Jo’s experiment report.
Report on the effect of fertiliser on plant growth
Introduction:
Our garden does not grow nearly as well as the
neighbour’s garden. I know that my Dad puts
fertiliser on the garden but I don’t think it works
because the plants don’t grow very well.
The hypothesis: Adding fertiliser does not make
plants grow better.
The independent variable will be changing the
amount of fertiliser given to the plants. One plant
will get no fertiliser. This will be the control. The
other plant will be given fertiliser, and this will be the
test plant. The dependent variable will be measuring
the height of the plants. The variables that will be
kept the same are the type of plants, the amount of
water, the soil type, and the amount of sunlight.
Materials:
Good observation Jo. There is a
problem here that needs
investigating.
Using a word like ‘better’ is
unclear.
Now we know what ‘better’
means.
The hypothesis would be clearer
if it were ‘Adding fertiliser does
not make plants grow taller’.
Only using two plants is a very
small sample size. Jo wanted two
identical plants but this is difficult
to get as most plants are slightly
different, just the same as people
are different. It would be better
to have more plants and work out
an average for the growth
measured.
2 snapdragon plants
fertiliser
measuring cup
watering can
ruler
2 pots (15 cm diameter)
garden soil
Jo should try to get at least five
plants to test with fertiliser and
five to measure that are not
given fertiliser.
It is also important that all the
plants are about the same size at
the beginning of the experiment.
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Report on the effect of fertiliser on plant growth continued
Method:
This is good.
1.
Two identical 15 cm pots were filled with the
same garden soil.
2.
Two snapdragon plants about the same size
were chosen from the punnet of seedlings.
Jo has written in the past tense: this
is a record of what was done. There
are no personal words like ‘I’ or ‘we’.
3.
One snapdragon plant was planted in each
pot.
4.
The pots were labelled, ‘with fertiliser’ and
‘control - without fertiliser’.
5.
The fertiliser was mixed the same as the
directions on the packet.
6.
The ‘with fertiliser’ plant was watered with
250 ml of the fertiliser mixture.
7.
The ‘control - without fertiliser’ plant was
watered with 250 ml of water.
8.
The plants were placed near each other in
the garden so they would get the same
amount of watering from the automatic
sprinklers.
This is good. Jo has made sure the
plants get the same treatment, only
the amount of fertiliser is different.
This is good. The variables that are
being kept the same have been
identified. The amount of light and
water is the same for each plant. Also
the soil is the same.
Jo would need to make sure that the
plants were not affected by insects or
disease.
9.
The plants were measured by placing the
ruler on the soil and finding the tallest shoot.
The height was recorded at the start of the
experiment.
10. The plants were then measured, using the
same method each Sunday for 8 weeks.
11. The height was recorded in the table.
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This is good. Jo has recorded the
starting height of each plant so she
can measure if there is any growth.
Because plants usually grow slowly,
watching and measuring them for this
long should be enough to measure
any change in the amount of growth.
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Report on the effect of fertiliser on plant growth continued
Results:
With fertiliser
Actual height
(cm)
Growth from
start (cm)
Without fertiliser
Actual
height (cm)
Growth from
start (cm)
Start height
10
11
Week 1
11.5
1.5
12
1
Week 2
13
3
13
1
Week 3
14
4
13.5
2.5
Week 4
15.5
5.5
14.5
3.5
Week 5
17.5
7.5
16
5
Week 6
18.5
8.5
17
6
Week 7
19.5
9.5
17.5
6.5
Week 8
20
10
17.5
6.5
3
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Report on the effect of fertiliser on plant growth continued
This is good. This is
good. The results
should be done in
both a table and a
graph.
The effect of fertiliser on plant growth
Total growth (cm)
15
10
With fertiliser
Without fertiliser
5
0
0
5
10
Time from start (weeks)
Discussion:
The results clearly show that the plant given fertiliser grew taller
than the plant not given fertiliser.
The table lets people
check the exact
results.
The graph gives a
good picture of what
is happening.
This is good. Jo has
interpreted the
results.
The fertiliser might have supplied something like a mineral that
the soil was lacking. Without this mineral the plants were being
starved and couldn’t grow properly.
This is part of
interpreting the
results. Jo has tried
to explain why the
results have
happened.
During the experiment I checked that the plants were both
getting watered by the automatic sprinklers and that they were
both getting the same amount of sunlight because the trees did
not shade that part of the garden.
This is an important
part of the evaluation
of the experiment.
On a couple of occasions I couldn’t find my ruler so I used a
measuring tape instead. This might have caused a small error in
measuring as the tape was difficult to hold straight. Also the tape
had larger marks on it so it might be less accurate than my ruler.
Jo has identified a
possible error that
might have affected
her results.
The experiment could be improved if I had tested more plants
and worked out an average. Also it would be good to test
different types of plants. I only tested snapdragon plants but it
would be good to see if all plants grew better with fertiliser.
This is good. Jo has
suggested
improvements to her
experiment.
Home gardeners and farmers would need to know that fertiliser
does really make a difference to how plants grow.
This is good. Jo has
pointed out where
her experiment could
be used. This is
identifying a
consequence for her
experiment.
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Report on the effect of fertiliser on plant growth continued
Conclusions:
This is what the
results show.
Fertiliser does make plants grow taller.
The hypothesis was not supported by the results.
This is consistent
with the results.
After doing the experiment Jo still wondered why the neighbour’s garden grew
better than her garden. Her experiment clearly showed that fertiliser did make a
difference so perhaps they used a different type of fertiliser. This could lead to
another experiment testing different types of fertiliser.
Now it is your turn to identify good points or errors in an experiment.
You will do this in Assignment 4a, the report on sports drinks.
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