Writing Your Lab Report
The results of scientific investigations must be properly documented and communicated
to both other scientists as well as the non-scientific community. Scientific experiments
and data are summarized and described in hundreds of different journals as well as
magazines, newspapers and books. Good, clear, concise writing skills are essential.
A scientific report is a compilation and analysis of your data that you collect during an
investigation. It is a permanent record of the experiment you undertook and as such
every effort should be made to ensure it is clear and accurate. Time and effort should be
put into writing all lab reports.
The following are guidelines for completing your labs. Length of each section has been
given as guidance.
General Format:
Title page & cover picture required for all reports.
Headings/sub-headings – 16 point font maximum.
Main report - 12 point font.
1 ½ line spacing maximum.
A full report will include all of the following sections:
Abstract: NOT THIS REPORT
A brief summary of your entire paper. It will clearly state the research question
(problem), the hypothesis and a brief summary of the experiment. A summary of the
data should be included and major conclusions outlined. One-two paragraphs should be
adequate.
Example:
The group conducted a two week study into the effect of the highly popular Peach
Snapple Ice Tea on Radish Plants. We used 6 large plant pots labeled Alpha through Foxtrot. The
group hypothesized that the Peach Snapple would help the Radish plants grow better than water
would.
From day one the pots that were given water produced seedlings unlike the Snapple fed
pots, which did not grow until day two at the earliest. Throughout the two-week study, the group
measured the height of the tallest stem in each pot in order to compare development between
the control groups and the experimental groups.
The data gathered showed that watering radish plants with Snapple impaired their
development compared to the radish plants that received water.
Introduction:
This section includes general background information on the topic. It should be a
summary of what scientific knowledge there is regarding the problem you are trying to
solve. You should gather material from textbooks, journals and online sources. All
sources MUST be cited in appropriate MLA/APA format, including parenthetical
references. If this is not done then the information may be considered plagiarized, for
which you will receive no credit. The lab report will then become invalid and receive a
score of zero and an honor code violation will be submitted. Plagiarism is an extremely
serious offense. Including words, phrases and sentences and placing them in quotations
does not get around being accused of plagiarism. At a minimum you should expect a
good introduction to be a page in length.
Example:
Snapple, a common household drink, was used in the experiment to see if it would boost
the growth of radish plants. Peach Snapple contains filtered water, sugar, citric acid, tea,
natural flavors (unknown). When the group started the experiment the hypothesis was that the
Peach Snapple would be able to boost the growth of the plants.
Research shows that citric acid in a pure form has a pH of 1.87. Although the recorded pH of
Snapple was not available, because citric acid is a major component in Snapple the drink itself
has an acidic pH of between 3 and 4, as measured using pH test strips. The pH of a substance is a
measure of the hydrogen ions. It is a logarithmic scale which means that for every unit change
on the scale the number of hydrogen ions increases 10 fold. The scale runs from 1-14. Above level
7 is called a base and below level 7 is an acid. Neutral is level 7. Acidic substances have the
greatest amount of hydrogen ions.
The radish plant is an edible root that came from Europe in pre-Roman times. The radish
plants used are the most common ones, a scarlet globe. They are a crisp, red, round, globe
looking plant. It has large, rounded, terminal lobes, and 1 to 2 linear leaflets. A radish plant can
germinate in up to 1 day. They can grow up to 3 feet when fully matured. In the plant pots that
contained water the radish plants germinated in only 1 day. A radish plant is rich in ascorbic
acid, folic acid, and potassium. Radish plants grow best in soil with an almost neutral pH of
around 6.5-7. (unknown)
By adding Snapple to the experimental pots the effect would be to lower the pH of the
soil in which the radishes were growing. Acidic soil can be toxic to plant roots. The acid can also
change the permeability of the plant cell membranes, which means that the plant will not be
able to regulate and control the substances that move in and out of its cells. This can weaken a
plant and affect its growth. Acidity of soil can also change the physical properties of the soil as it
can change the mineral content and composition. Plants rely on soil minerals such as nitrates,
phosphorus, and magnesium for their growth. (Schutt)
Materials & Methods:
This is a summary of the materials you used and an explanation of what you did. It
should be in list, bullet or number format and should be in sufficient detail that
someone could replicate your experiment.
Example:
Materials:
1. Radish Plants
2. Water
3. Snapple Peach tea
4. Large plant pots
5. Graduated cylinders
6. Ruler
Method:
1. Take 6 large plant pots and label them Alpha through Foxtrot.
2. Fill each plant pot up to the measuring line with soil.
3. Plant 3 radish seeds exactly a half an inch into the soil.
4. Plant pots labeled Alpha, Bravo, Charlie were the controls and were given 40 ml of water
every day.
5. Plant pots labeled Delta, Echo, Foxtrot were the experimental group and were given 40
ml of Peach Tea Snapple every day.
6. Continue steps 4 and 5 every day for two weeks.
7. Take a measurement of the height of the tallest stem in each pot every day. Record in
the data table.
Results:
This section should include tables and graphs that summarize all the data you gathered.
Tables and graphs are a great visual representation of data and are generally much
easier to read than paragraphs of text.
Data tables should never be split onto more than one page. Each table should have a
number, e.g. Table 1; table 2 etc and have a title. Graphs should also be numbered but
as figure 1, figure 2 etc and they too should have a title. Beneath each table and graph
there should be a summary statement of what the table or graph is showing or the
trend seen in the data.
Example:
Table1: Radish growth by day.
Day
1
2
3
4
5
6
7
8
Alpha
5
6
7.5
9.5
10.5
13
13
13
Average
9.69
Average by
group
Height of tallest stem (cm)
Control Group
Experimental Group
Bravo
Charlie
Delta
Echo
Foxtrot
5
4
0
0
0
7.5
7
1
0
0
10
8
1
0
0
11
10.5
1
0
0
11
11
1.5
0
0
11
14
2
0
0
12
14
2
0
0
12
15
2
0
0
9.94
10.02
10.44
1.31
0.0
0.44
0.0
Table 1 shows the growth of the plants in each pot over the time of the experiment. As the data
shows, the control group grew an average of 10.02cm in the two-weeks that the experiment was
running, compared to the experimental group, in which growth was only seen in one of the three
pots.
Figure1: Growth of control group
Height - cm
Growth of Radish Plants - Control
Group
16
14
12
10
8
6
4
2
0
Alpha
Bravo
Charlie
1
2
3
4
5
6
7
8
Day
Figure 1 shows that all the pots in the control group had growth over the time of the experiment.
The plants in the pots labeled Charlie grew the tallest, while the plants in the pot labeled Bravo
grew the fastest but slowed after day 4.
Conclusion
This section must include the following:
 State whether or not you accept or reject your hypothesis.
 Explain what your data means. Recognize the limitations of your data, such as
sample size. Look critically at the data and explain it thoroughly. If you believe
your data is flawed then say so and attempt to explain why.
 Explain the significance of your results and come to some conclusions, based on
the scientific research you did for your introduction.
 Describe how you would improve the experiment
 Describe how you could extend the investigation. What other conditions could
you consider varying?
A full conclusion will be at least a page in length and should have some basis in science.
You should tie this section in with the background information you gathered at the start
of the report.
Example
The hypothesis was that the pots that received Peach Tea Snapple would have better growth
compared to those that were only given water. The hypothesis was wrong. The pots that
received water grew considerably better.
Although the data showed a vast difference in the growth of the experimental and control
groups it may not be conclusive. Even though three plant pots were used for each group, more
could have been set up in order to increase the sample size. The more data you have the more
reliable the results are. More seeds could also have been planted in each pot and measurements
could have been taken from all the plants, not just the tallest in the pot.
A conclusion that can be drawn is that a liquid with a low pH (high acidity level) does not
improve the growth of plants. According to the data collected it actually appears to inhibit the
growth. In two of the experimental pots there was no growth, so acid conditions may also affect
seed germination. This is consistent with the research which stated that acid soil can affect plant
growth by weakening the plant and altering the mineral content in the soil. Acidity can also
affect membrane permeability.
The experiment could have been improved by taking the pH of the Snapple and the soil
beforehand, and re-measuring it daily as liquid was added to the soil. More data sets could have
been gathered by using more pots and increasing the number of seeds planted.
Further experiments based on this investigation could include testing to find out at what pH
plants grow best, or using different kinds of acid on plants to see if different acids, other than
citric acid affect plant growth. You could also investigate the effect of watering both the plant
leaves and the soil with acid solutions to see if the acid affects the plant leaves.
Works Cited
References used in the report should be listed in alphabetical order. You can use
programs such as noodletools (available on computers in the school library) or you can
insert references using the toolbar in Microsoft Word.
Works Cited
Schutt, John. Nitric acid & the growth of radishes.
<http://schutt.net/john/science/Nitric_Acid_and_the_Growth_of_Radishes.pdf>.
unknown. The Grow Spot. <http://www.thegrowspot.com/know/f7/all-aboutradish-53868.html>.