Proper Lab Report


How to Write a Proper Scientific Lab Report in S.A.C. Science Classes

 The following lab format was taken from the Ministry of Education web site under the SCIENCE COURSE profile.

 Writing Scientific Lab Reports

The purpose of a scientific lab or research report is to reveal to others some specific data you have collected and what you think they mean. A report must be written as concisely and clearly as possible so that the reader can grasp the material quickly and could accurately repeat or expand on your research. Whether you are writing a lab report for a course, a graduate thesis, or a paper for publication in a scholarly research journal, the format is similar to the one described below.

1. Title

The title of a report should indicate exactly what you have studied, e.g., The Effects of Light and Temperature on the Growth of the Bacterium, Escherichia coli. This title explains the environmental factors manipulated (light and temperature), the parameter measured (growth), and the specific organism used (E. coli). If a large number of variables or organisms were used, the title could say “Several Factors...” or “Various Chemicals....” It is unnecessary to include words such as “Observations on the Effects of...” or “A Report on the Effects of...” or “A Study on the Effects of....”

2. Abstract

The abstract is a condensed version of the entire paper. It allows a reader to quickly understand the purpose, methods, results and significance of your research without reading the entire paper. Abstracts or papers published in scholarly journals are useful when conducting library research, because the researcher can quickly determine whether the research report will be relevant to the topic. The material in the abstract is written in the same order as that within the paper, and has the same emphasis. An effective abstract should include a sentence or two summarizing the highlights from each of the sections: introduction (including purpose), methods, results, and discussion. To reflect the content of the paper accurately, the abstract should be written after the final draft of your paper is complete, although it is placed at the beginning of the paper.

3. Introduction


The introduction should identify the problem or issue and give background information (historical and/or theoretical) about that problem. The introduction contains a brief literature review which should describe previous research conducted on the problem, and explain how the current experiment will help to clarify or expand the knowledge. This information should justify why you conducted the experiment. All references to previous studies should be properly documented. The introduction should end with a purpose statement, sometimes in the form of a hypothesis or null hypothesis. The purpose statement is a single sentence which specifically states the answer to the question that the experiment was designed to answer; e.g., the purpose of this investigation was to determine the effects of environmentally realistic exposures of acid precipitation on productivity of field-grown and chamber-grown peanuts.

4. Materials and Methods


In the materials and methods section of a formal lab report, you should describe how and when you did your work, including experimental design, experimental apparatus, methods of gathering and analysing data, and types of control. This section must include complete details and be written clearly enough to allow readers to duplicate the experiment if they so wish. This section is written in past tense because you have already done the experiment. It should not be written in the form of instructions or as a list of materials, as in a laboratory manual. Instead, it is written as a narrative describing, either in first person active voice or in passive voice, what you did, e.g., first person active voice: I filled six petri plates with agar; passive voice: six petri plates were filled with agar. Methods adapted from other sources should be referenced. Photographs, maps and diagrams may be used to help describe the experimental set up (see Tables and Figures below).

5. Results


In the results, you present your observations and data with no interpretations or conclusions about what they mean. Tables and graphs should be used to supplement the text and to present the data in a more understandable form (see Tables and Figures below). Raw data will probably be most effective in table format, with the highlights summarized in graph form. The written text of the results section may be as short as one sentence summarizing the highlights and directing the reader to specific Tables and Figures. Use past tense to describe your results. Sample calculations for a lab report in a course may be included in a separate section titled, “Calculations,” or in an Appendix at the end of the report.

6. Discussion


Explain what you think the data means. Describe patterns and relationships that emerged. Compare these results to trends described in the literature and to theoretical behaviour. Explain how any changes to, or problems with, the experimental procedure may have affected the results, or offer other suggestions as to why the results may have been different from or similar to related experiments described in the literature. Interpretations should be supported whenever possible by references to the lab manual, the text, and/or other studies from the literature, properly documented. Remind the reader of your own results, when relevant, without repeating endless information from Results. If the lab manual includes questions to be answered in the Discussion, integrate the responses into a logical discussion, rather than answering them one by one. In addition, do not include only the answers to the questions – use them as a guideline for supplementing your discussion, not limiting it.

7. Literature Cited

Also called “References” or “References Cited,” this is a list only of papers actually mentioned (cited) within the report. (A “Bibliography,” on the other hand, refers to a list of all materials used to get background knowledge on a subject; you will not usually be required to include one in a scientific lab report.) Remember that all information within the report that is not your original work or ideas should be referenced (not necessarily quoted, but paraphrased or summarized – quotations are rare in scientific writing.) There are several standard styles for documenting references. Check with the teacher for their preference. You may be asked to follow the format of a particular journal in your field. If so, follow that format exactly.

8. Tables and Figures

Tables and figures are often used in a report to present complicated data. Use the following guidelines to incorporate them effectively. Each table or figure must be introduced within the text, and the comment should point out the highlights, e.g., The temperature increased on the third day (Figure 1). All tables and figures must be numbered and have self-explanatory titles so that the reader can understand their content without the text, e.g., Table 1. Per cent of soybean plants exhibiting visible injury after exposure to acid rain. Tables and figures are assigned numbers in the order they are mentioned in the text. Tables and figures are numbered independently of each other, e.g., Table 1 and 2, and then Figure 1 and 2 as well. Tables are referred to as tables, and all other items (graphs, photographs, drawings, diagrams, maps, etc.) are referred to as figures. Tables are labelled at the top and figures at the bottom. Tables and figures may be placed at the end of the paper, or within the text as soon as possible after they are mentioned without interrupting the text, e.g., at the end of a paragraph or section.

Copyright the University of Guelph, 2002 - 1991. (Used with permission.)

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