Lab Report/APBio/Smockadapted from Mader
Preparing a Lab Report
Lab Report Preparation Form
1. Introduction: Tell the reader what the lab exercise was about.
a. Background information: Begin by giving an overview of the topic.
Look at the introduction to the laboratory. Do not copy the information,
but use it to indicate ideas about what information to include. For example, suppose
you are doing a laboratory report on photosynthesis. You might want to give
a definition of photosynthesis and explain the composition of white light.
b. Purpose: State the purpose of the lab.
Think about the steps of the experiment, and then decide what its purpose was. If you
tested the effect of white and green light on photosynthesis, you might state that the
purpose of this experiment was to determine the effect of white light versus green
light on the photosynthetic rate.
c. Hypothesis: State what results you expected to get.
Most likely, the introduction to the laboratory will suggest the expected results.
State this in the form of a hypothesis. For example, you might hypothesize that white
light would be more effective for photosynthesis than green light.
2. Procedure: Tell the reader how you did the experiment.
a. Equipment used: Help the reader envision the experimental setup.
Read the experimental procedure, which describes how the experiment is conducted.
Describe the equipment in your own words. You might state that a 150-watt lamp
was the source of white light directed at Elodea placed in a test tube filled with a
solution of sodium bicarbonate (NaHCO3). A beaker of water placed between the
lamp and test tube was a heat absorber.
b. Collection of data: Tell the reader how the experiment was done.
Think about what you did during the experiment. What did you observe, or what
did you measure. You might state that the rate of photosynthesis was determined
by the amount of oxygen released and was measured by now far water moved in
a side arm of the test tube.
3. Results: Present the data in a clear manner.
a. Graphs and tables: If at all possible, show your data in a graph or table.
Look at any tables you filled in during the experiment and reproduce those
sections that pertain to data collection. Do not include any columns that have
to do with interpretation.
b. Description of data: Examine your data and decide what they tell you.
In the sample photosynthesis lab, you might state that the data in the table indicate that
the rate of photosynthesis with white light was faster than with green light.
4. Discussion: Interpret your data and offer conclusions.
a. Support of hypothesis: Tell whether the hypothesis was supported.
Compare your hypothesis with your data. Do your data agree with the hypothesis?
You might state that your results supported the hypothesis that white light gives a
higher rate of photosynthesis than green light.
b. Explanation: Explain why you think you got the results you did.
Look at any questions you answered while in the laboratory and use them to help you
decide on an appropriate explanation. For example, the answers to the questions in the
photosynthesis example lab might help you state that white light gives a higher rate of
photosynthesis because it contains all the visual light rays. Green light gives a lower
rate of photosynthesis because green plants do not absorb green light. Be sure to report
your data exactly. If your results fail to support the hypothesis, explain why you
think this occurred.
c. Conclusion: Review the entire experiment in your mind, and then explain what you
learned. You might state that you learned that the quality of light can affect the
rate of photosynthesis.
Points to remember:
1. Clarity. Your report should be organized and presented so that the reader can easily understand your work.
2. Good writing. Pay particular attention to grammar and style. Your writing will be enhanced by careful proofreading and revision.
3. Observations and interpretations. Keep the distinction between observations and interpretations clear. These are frequently confused in laboratory reports.
4. Exercise good judgment. As you prepare your report, you will constantly make difficult decisions about how best to present and interpret your data. Your attention to these decisions will be reflected in the quality of your report.
Submit:
Submit a typed lab report with four sections – introduction, procedure, results and discussion.
All information should be presented sequentially. Do not place tables and graphs at the end of the report, expecting your reader to flip back and forth in order to understand your work.
Tables and graphs may be hand-drawn. Tables and graphs must be very neatly executed.
Laboratory Report Preparation Form
1. Introduction
a. Background information
b. Purpose
c. Hypothesis
2. Procedure
a. Equipment used
b. Collection of data
3. Results
a. Graph or table
b. Description of data
4. Discussion
a. Support of hypothesis
b. Explanation
c. Conclusion