Lab report Procedure and Requirements
A scientific paper is an important method of communication.
Therefore, the paper must be well organized and concisely written.
A lab report is no different from a published report in a scientific journal.
Although each journal has its own requirements and stylistic techniques,
in this assignment we will use examples of those required specifically
for a high school Biology class.
The purpose of doing the investigation is very important. In this
section, you will summarize what you already know about the project,
as well as indicate the reason for doing this particular experiment.
The purpose is best written in the past tense with passive voice.
It must follow a logical pattern of reasoning, so organization of the information
before this section is written is important. General statements
related to the topic are presented first, and as the narration continues,
the statements become more specific. The progression from general
to specific helps the reader to “focus in” on the hypothesis or the problem.
The terminating statements should precisely define the problem being
investigated. The variable, measurements that will be made, and/or
organisms studied are identified. An example of a “purpose” section
for a lab report follows:
Photosynthesis is an important process not only for plants,
but for all living things. In this process, carbon dioxide and water
are used in conjunction with light energy to create a substance that stores
energy in its bonds, as well as oxygen as a byproduct. The rate of
photosynthesis varies with several factors, among them the amount of carbon
dioxide present, the light, and the type of organism. In this investigation,
we will investigate the rate of photosynthesis in the water plant Allium.
Temperature and the amount of carbon dioxide will remain constant, but
the amount of light will vary. The rate of oxygen produced will indicate
the rate of photosynthesis. This rate will be measured by counting
the bubbles evolved from a cut stem of Allium during a specific
The procedure or methods section describes the materials needed and
the experimental procedure. It is NOT a list of materials,
then a numbered list of steps. The materials are NOT listed
independently, but are identified within the description of the experimental
procedure. The procedure must be concisely describe in sufficient
detail that it might be duplicated. During the course of the
experiment, careful recording should be made of everything that is done,
so that it may be replicated in this section. The procedure is written
in past tense with a passive voice, and follows a chronological
sequence. The specific variables, controls, organisms, parameters,
time frames and any other pertinent information are given in the experimental
directions. The terminating sentence should indicate how the results
or data will be interpreted. An example of a procedure section
Cuttings of Allium containing growing new leaves were
placed into test tubes, with the stem upward, along with a calcium carbonate
solution that would maintain a constant high carbon dioxide availability.
Temperature of the cuttings was maintained at room ambient temperature.
Two test tubes with Allium were set aside as a control. Two
were exposed to increased light, in the form of a 60 watt bulb at a distance
of 20 cm from the test tubes. Oxygen production from the plants was
measured in the form of bubbles coming from the stems. The rate of
oxygen production was measured every minute, for a period of time of ten
minutes. This bubble production will be analyzed to directly determine
the importance of light intensity to rate of photosynthesis.
The results or observations section includes data collected and observations
made during the experiment. The data may be represented as tables
or figures, but some narrative must be included. Each table or figure
must be described and explained. Comments should be offered that
will contribute to the reader’s understanding and interpretation of the
data. The narration of the results section is written in the past
tense. Specific data should be used in chronological order to
focus the reader on unusual or significant data.
In the conclusions section, the data from the results are interpreted.
What the results indicate, what relationships or patterns exist are shown.
The investigator also compares his or her results to those that
were expected or those that were obtained in previous experiments.
This section commonly follows an inductive line of reasoning.
A discussion of the specific, significant data is presented, and the section
is terminated with a general conclusion. An example of a conclusion
In this investigation, it was seen that both of the experimental
Allium plants increased their production of oxygen bubbles by 50
percent with an increase of light exposure for a ten minute period. Photosynthesis
rates increase with increased light intensity. This may be of value
and importance for those plants that exist in different climates and locations.
Your lab report should represent your best efforts. It should
be completed neatly and have numbered pages. Do not start a separate
page for each section. Instead, each section should immediately follow
the end of the previous section. Proofread your entire paper for
errors. Make it look as professional as possible!
Lab report example.