How to write a laboratory report

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Laboratory Reports

Purpose

Laboratory reports are required to help you learn to write in a professional manner consistent with the expectations of workers in the discipline. When writing reports attempt to write to intelligent readers who have not read the lab exercise but know about the general subject. Pretend you are planning to submit your work to the Journal of Physiology for evaluation

Notes on Writing Reports of Your Experiments

No experiment is complete until the conditions of the exercise and its results have been clearly stated, and conclusions have been drawn from the results. A record should be kept of all observations, measurements, demonstrations, and maintained in a good quality lab notebook. While discussion between lab partners and sharing of data is expected, the writing of your lab reports is not a group or team activity and must be done independently. The written account of the experiment must state what you did, why you did it, what you found, and how you interpret the results. Be concise, clear, informative and accurate.

Lab reports will include the following six sections:

A. Brief, descriptive TITLE.
B. A concise ABSTRACT (one paragraph).
C. An INTRODUCTION that includes background information.
D. A short description of MATERIALS & METHODS used to complete the experiment.
E. A RESULTS and DISCUSSION section containing:
a) Clearly labeled charts, graphs, tables, diagrams, etc., with
legends.
b) A carefully written descriptive narrative.
c) Discussion and interpretation of results and their meaning.
F. REFERENCES - Some of these will be located in the lab but most of the reference information will be found at the library (primarily at Kendall). This is called the "primary literature".

The following narrative gives a brief description of the information that should be included in each section.

Title: Give a brief title of the investigation and the date(s) on which it was conducted.

Abstract:

The Abstract is a qualitative summary of the results describing events measured, witnessed, etc. in lab. Only slight reference should be made to the methods since these are in the lab directions. However, do report any changes in the methods that differ from the given directions. Attempt to express the results in general, but meaningful terms. Emphasize the principles illustrated by your data. See example below for an exercise on frog muscle contraction.

Sample: The frog sciatic nerve-gastrocnemius muscle preparation was exposed to single electrical stimuli of varying intensity (voltage) and duration (pulse width). There was no response to sub-threshold stimuli, and graded responses to supra-threshold or sub-maximal stimuli. Increasing the pulse width above 1 msec reduced the voltage necessary to elicit a response in the muscle. A single muscle twitch consisted of a short latent phase, and a contraction phase that was approximately 50% of the relaxation phase in duration. The sciatic nerve conducted action potentials at a speed of 27.5 M/sec at 20oC and had a relative refractory period of approximately 2.5 msec. These results are consistent with the expected findings for this preparation (reference) and were illustrative of neuromuscular principles.

Introduction

Explain what the experiment is designed to investigate and the significance of the phenomena being studied. First, you should provide some relevant background material from your reading (for example, one of your references!) and your lab handout. Then focus on the specific problem that is being addressed. If possible, state the hypothesis that you are testing.
Whatever questions you raise in the Introduction must be addressed in the Results and Discussion. For example, if you state that you are testing the hypothesis that certain marine animals are osmoconformers, then you must clearly indicate if your results support or refute this hypothesis in the Results and Discussion section. In other words, the Introduction really sets the stage for the rest of the lab report.

Materials and Methods

Include the genus, species, and common name of the animal(s), a description of the apparatus and, where it would be helpful, a diagram of the apparatus, full details of the experimental procedure, special precautions ...