It is difficult to overstate the need for good verbal and written communication. The most significant advances in research may be overlooked or misunderstood if they are not communicated properly to their target audience. Just as importantly, your professional image may either be tarnished by poor writing, or be boosted by excellent communications skills.
The best way to improve communication skills is by practice. You can also your improve writing skills by critical reading of journal articles and textbooks. This guideline is not meant to be a blueprint for good lab reports; it is an attempt to address a number of common shortcomings of "full" lab reports.
When writing your lab reports, the two most important pieces of advice are:
You have just done an experiment and you wish to write a report describing it. In constructing your report -- or any other form of communication, for that matter -- the two fundamental concepts to keep in mind are (i) your message, and (ii) your audience.
Your message should basically answer the following three questions:
Your must always keep in mind the main point(s) you mean to communicate. Keep your writing simple and to the point. In particular, extensive rambling is a sign that you either don't know the material, or that you have not organized your ideas well. Don't try to impress your audience with your extensive knowledge of peripheral topics.
As you compose your report, you must always keep your audience in mind. And I don't mean your course instructor! Like research papers, lab reports are meant to be read by your scientific peers. Although you must assume that your readers have general training in science, don't assume a familiarity with details that are very specific to your experiment. For example, if you were to write a Full Report on the Gravimetric Determination of Sulfate experiment, you would assume that your average reader would only need to be reminded of the general principles of gravimetric analysis -- so you need only provide a brief (1 paragraph) summary of those priciples. However, details that pertain to your specific experiment -- analysis of sulfate using a certain reagent -- might need to be explained more fully.
A written lab report is a fairly comprehensive document. Research articles in Analytical Chemistry or the Journal of the American Chemical Society are good models. You should look at the articles in these and other journals and use them as guides. However, you must realize that the style and organization of a lab report varies from person to person and from experiment to experiment. Different formats may be appropriate for different experiments.
With this in mind, the following format is standard for most scientific writing:
Again: this format is a general guide. You must ultimately decide on the format appropriate for your work.
The purpose of an abstract is to summarize the purpose, results and significance of your work. It should be short, usually less than 100 words or so. In this class, the abstract should answer the following questions:
In addition to answering these questions, you should state any other conclusions warranted by your results. If the sole purpose of the experiment was to measure analyte concentration in some sample, then it is sufficient to report the analyte concentration (as a confidence interval) and perhaps make a statement about the suitability of the analytical technique for the analysis of your sample. Your experiment may have had an additional purpose other than quantitative analysis (eg, to compare the characteristics of two different analytical techniques); if so, you should summarize your conclusions regarding this other goal.
By reading the abstract, and perhaps glancing at the figures and tables, the reader gains a brief overview of paper. Abstracts are meant for browsing reports or journal articles. I like to think of the abstract being for a supervisor or colleague who doesn't have time to read the entire lab report in detail, but just wants to know "the bottom line."
This portion of your full report is exactly the same as the Abstract Reports that you submit for other experiments. Please refer to the instructions for these reports for more detail on how they are written.
The Introduction section sets the stage. You should present/summarize the background necessary to understand your work and its significance. Don't try to be too comprehensive; write about topics that are most pertinent to your experiment. You might choose to focus attention on the specific analytical technique you are using, or on a particular area of application of the technique, or both. This section must be concise enough that experts are not bored, but are instead reminded of the main principles. However, the introduction needs to be comprehensive enough that non-experts are given enough information to understand the main points of your results and conclusions. Additional references should be cited for non-experts who need more detail.
Finally, after presenting the relevant background, you should describe
For example, let's say you used fluorescence analysis in a clinical assay. You might summarize the analytical technique used (fluorescence) or the application (clinical analysis), or both, depending on the focus of your report. You must keep in mind that the reader may be either a specialist in fluorescence spectroscopy or a clinical lab technician, and plan your report accordingly.
This section should provide all the information needed to reproduce the experiment. This does not mean you have to re-write the experimental procedure verbatim. It is common in scientific journals practice to refer to another paper for a full account of an experimental procedure. However, it is courteous to provide a brief (1-2 paragraph) summary of the experimental procedure, so that the reader does not have to look up another article to have an inkling of your experimental work. If the reader actually wishes to repeat the experiment, then s/he would expect to look up the original reference(s) for all the details.
Any deviations from the recorded procedure must be given in detail. This does not mean that you must include pedantic, trivial or implicit/obvious details; be clear and complete without excessive and detracting verbosity.
If instrumental analysis is used, one detail that should always be provided is the make and model of the instrument used for the analysis.
In this section you should present
Even though tables and figures can summarize a great deal of information, you should provide a "verbal tour" of all your data and results. In this section, ORGANIZATION is key. There is almost always a great deal of data. Note that not all calibration curves need to be included in the report, just representative ones. The final results should be displayed prominently.
In this section, and throughout your report, all figures and tables should be labeled (figure 1, table 2, etc.) and titled. In tables, each column should have a descriptive heading that includes (if appropriate) the proper units for data or results. The axes of all graphs should be well labeled (including units) and the data points should be clearly defined. Curves in the graph should never obscure the experimental points; if each data point is the result of repeated measurements, then error bars should be included.
A caption that summarizes the contents of the figure/table should also be included. In most cases, the reader should not need to refer to the text to understand a figure or a table. Don't worry if you repeat material that you cover elsewhere. Remember, many people will scan just the abstracts, figures and tables.
NOTE: in your lab handouts, there is a table provided to turn in your raw data. The purpose of this table is to help me evaluate your accuracy, precision, and calculation grades. This table is not meant to be included in the Data/Results section of your lab report. Make your own tables! It is not necessarily appropriate to include all your raw data in a lab report, anyway. For example, it would be assumed by your audience that you - the author - are capable of typical calculations such as subtraction (for mass by difference) or construction of confidence intervals. However, as your lab instructor, I don't make that assumption!
The discussion of errors may be included as part of the Discussion section, or can be a separate section, depending on the length and depth of your treatment. In this section you should identify, as quantitatively as possible, the primary sources of error in your final results. You should address issues specific for your experiment, not for the technique as a whole (although it may be necessary to point out some of the inherent weaknesses of the analytical method in order to explain your errors).
This section is your opportunity to demonstrate an understanding of
To begin this section, you may want to summarize your results, and perhaps make a comment regarding the suitability of this technique for the analysis you performed. You should state your conclusion(s) at some point in this section.
Good discussions require thought and additional reading (i.e., library work). This section is your chance to impress me. Go beyond the book and the lecture. You may wish to give a theoretical description of the method, a discussion of other applications of this technique, a comparison of another technique for this application, or a general discussion of the merits and disadvantages of this technique in analysis.
My own advice is the following: don't attempt to address too general a topic in this section. It is much more difficult to write a discussion on a broad topic than on a specific one.
Literature references provide the reader with access to other available information and data. Standards for bibliographic listing exist; the format of the citation (in the body of the report) and the bibliography is slightly different for the various scientific journals. You should refer to a few of these for examples. Personally, I prefer numbered citations, rather than Author/Year, as some journals use.
Even though they have been mentioned, it is worth emphasizing the following points: