WRITING A SCIENCE LAB REPORT
A cornerstone of scientific experimentation is that an experiment can be repeated by other investigators and the same results achieved. In order to make this possible, a written record of the experiment must be kept including the analysis of the data, observations, inferences and/or conclusions reached. Anyone reading your lab report should be able to reconstruct your experiment precisely in its entirety.
The outline for your report should follow the report outline given below. When you are asked to write a report of an experiment in which the results and your interpretations are of primary importance, the procedure is usually outlined for you. Lab reports are written with precise language, not flowery or verbose language. In other words, say what you mean and leave out the filler and fluff.
I. Title
The title says what you did. It should be brief (aim for ten words or less) and describe the main point of the experiment or investigation. An example of a title would be: "Effects of Ultraviolet Light on Borax Crystal Growth Rate". If you can, begin your title using a keyword rather than an article like 'The' or 'A'.
II. Purpose/Problem
The purpose or problem states the reason(s) why you are doing the experiment. Write down exactly the problem that will be investigated or experimented. Purposes can be and often will be stated as an open-ended question. Example: What will happen when Substance A is exposed to Substance B?
III. Introduction/Research:
In a few words tell what you already know or have found about the problem that will let you make an educated guess. This is your background information from the text, teacher, or other sources. It gives the reader an understanding of underlying principles and content information of the laboratory.
IV. Hypothesis
Describe the theory which will be tested during this experiment and predict what will happen. From a sentence to a paragraph in length.
What do you expect to find? The hypothesis can be stated as an "If..., then..., because…" statement. The 'If' part of the statement is based on related facts that you know to be true, and the set-up of the problem. The 'then' part of the statement is an educated guess on the outcome of the experiment. The 'because' part is an explanation of why you think that will be the outcome. The hypothesis does not have to guess the correct outcome, but the experiment must be set up to test the hypothesis.
V. Materials/Supplies:
This is a list of all equipment and chemicals used to do the experiment. Please include quantities (amounts).
VI. Procedure
Carefully explain, in a step-by step fashion, what is done in this experiment. This may be a narrative or a list of specific steps, but must instruct others to duplicate your procedure precisely.The procedure tells exactly what you did. Be specific. The procedure you use affects the results. So, it is important to be accurate in explaining what you did. It may be helpful to provide a figure to diagram your experimental setup.
VII. Observations and Data:
The observations tell exactly what happened when you did the lab. An observation is measurable information that comes to you through your senses. Results include experimental (raw) data in the form of well-labeled tables, drawings and other observations. Place your observations and data in this section without discussion or comment. This is where you include any calculations made during the experiment. If the experiment lasted more than one day, be sure to date each day’s recordings.
VIII. Data and Analysis
Document the results of your experiment. Include tables, graphs, drawings or any analysis performed directly on the data.Make inferences based on the gathered observations in this section.
IX. Conclusion
Briefly state what is learned from the logical interpretation of the data. This conclusion should answer the question posed in the statement of purpose, as well as any questions asked as part of the lab.Conclusions explain your observations and describe how your data relates to the problem. It is written in paragraph/essay form and should include why you did this experiment (restate the purpose/problem). You should explain in your own words what you found out or discovered. Your conclusion should state whether or not the data confirms or rejects your hypothesis. Discuss any errors as well as any patterns you see. Part of the conclusion may be a new hypothesis based on your findings and suggestions for testing the new hypothesis in a different experiment. You may also make any predictions you would expect based on what you discovered.
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