HOW TO WRITE LAB REPORTS FOR BIOLOGY
**Please note that this document is on the web. The underlined phrases are links to other pages on the web
This document contains instructions for writing a lab report in scientific format. It was created and edited by the biology faculty at Union College. A example of scientific writing is also included at the end of this chapter.
The Effects of Jumpamine...... (although not a real paper, it is written with correct format).
Unless otherwise told by your instructor, lab reports are to be an INDIVIDUAL effort. You may discuss the lab and the data, but do not look at anyone else report (rough draft or final version). You should not even outline the report together. Many students have received a severe penalty for plagiarizing lab reports from their lab partner or from someone else.
You should think of your lab report as a Research Report. It should be written as if you were going to submit it to a scientific journal for publication. Therefore, it should follow a very precise format and should be written for a general audience, NOT just your instructor.
Laboratory reports should be double spaced on 11 x 8 1/2 white paper (or graph paper where appropriate) using just one side of the page. Typing is required except for tabular data and complicated formulae and equations which may be neatly hand-lettered in ink. Submit the report on its due date; excuses such "the computer was down" are not acceptable.
Although there are many minor variations in the format of scientific reports, almost all of them conform to the basic principles set out below, and you should follow this format for all of your lab reports.
FORMAT OF A RESEARCH REPORT
GOOD Examples: See sample paper (fictitious): "The effects of jumpamine chloride...."
BAD examples: What NOT to do
- Your reports will be read critically, not only for scientific content and logic, but also for your ability to express yourself in this form of writing. The text should be organized into logical paragraphs and sentences. Each paragraph should start with a topic sentence which introduces the information in that paragraph.
- Be sure to proof-read. Since most word processors have spell checkers, there is no excuse for mis-spelled words.
- When you are writing about methods and results, be sure to use past tense because you have completed the experiments by the time you begin writing.
- It is often desirable to use we and I in a research paper. However, some journals prefer passive voice.
- Scientific writing should be clear and concise. Don't use five words when two will do. Work on clarity and organization in your presentation.
- Too long: "The effect of obesity on heart rate was the purpose of the experiment"
- Better: "We investigated the effect of obesity on heart rate".
- Bad: "We obtained an aquarium and then we put the fish in it."
- Better: "All experiments were performed in a 10 gallon aquarium." This is includes more information and leaves out the trivial detail 'we obtained a...'.
- Too long: "The effect of obesity on heart rate was the purpose of the experiment"
- Scientific binomials (genus and species names) are Greek or Latin, and are therefore underlined or italicized.
On this page give the title of the report, your name, the date, the day of your lab section ( e.g. Tuesday, Wednesday), and the name of your lab partner (if you have one). Your title should be very informative. It can even be a sentence that summarizes the most important result. Your title is the only text likely to be read by a large number of scientists.
This section is as short as a few paragraphs or as long as a few pages. It serves to introduce your experiment. Start with general statements and become more specific.
The first part of the introduction should set the context for your experiment by briefly providing background information. You should present what information is known from previous studies, and then state what additional information your experiment may provide. Be sure to give proper citations when you state facts or ideas from outside sources.
EXAMPLE: The larch is an evergreen that loses its leaves in the fall (Jones, 1921).
See other examples of citations in "The effects of jumpamine chloride....".
In the second part of the introduction you should describe the specific questions you chose to study. State what you did in a general way, eg., "We investigated the effect of obsesity on heart rate by comparing heart rates of fat an thin people after they climbed stairs", but do not give away the specific details of your Methods or Results. Specifically state your hypothesis at the end of the Introduction. However, not all scientific studies, have a hypothesis; the scientist just wants to obtain more information . You need to decide whether a hypothesis is appropriate for your study.
The experiment has been completed by the time you write your report, so use past tense. This section includes a brief outine of the methods used in the experiments For any details that are contained in other literature (eg., your lab manual), you may refer the reader to the methods described there by using a proper citation; you do not need to reiterate these details in your report. However, if the laboratory procedures were changed, describe these in this section.
The purpose of this section is to allow other experimenters to duplicate the methods you used, so it should be detailed enough so that someone else could read your report and repeat the experiment. However, you should NOT include trivial details such as "we used test tubes that were 10cm long," or "the test fish were kept in a beaker before the experiment began."
It is important to quantify your treatments whenever possible; for example, how many milligrams of caffeine did each person injest, or how long did you wait between administering salt and measuring blood pressure?
We exposed cells to 0, 15, 30, or 45 seconds of ultraviolet irradiation. Cells from each irradiation treatment were diluted to 10-3 and 10-5 of their original concentration. One ml of each of these dilutions was plated on nutrient agar and incubated overnight. The number of colonies was counted the next day.
Our lab bench received cells from treatment #1, and these were serially diluted, so that there were 2 different concentrations of bacteria to count on the petri dishes. Lab bench 2 received cells from treatment 2. These were also serially diluted, resulting in 2 different concentrations of bacteria to count.
Problems with the bad example, which contains nearly the same number of words but much less information:
- Trivial information is included (Our lab benched received...)
- "Treatment #1" is a poorly identified variable. The reader will probably have to refer back to a previous page to find out what this treatment is.
- Important details are left out, such as the number of seconds the cells were irradiated, the dilution factors, and the temperature at which the cells were grown.
ResearchReports.phpReturn to page 1.
The results section always starts with normal paragraph (text ) format, NOT with tables or figures. You MUST first direct the reader's attention to EACH table and figure before they appear, indicate what they show, and summarize the important data in each.
Good Example of How to Begin the Results:
The mean IQ of Union biology students was found to be higher than the mean IQ of Harvard students and of students from many colleges, as seen in Figure 1.
As with all writing the results should be organized into coherent logically organized paragraphs and sentences. .
Data is reported in 3 ways:
- Text or paragraph form, if there are just a few numbers to report.
- Figure: a graph, picture, or diagram
***** A figure will have a detailed legend at the bottom ******
- Table: something that contains only numbers, and has a detailed legend at the top.
See examples of figures in, "The effects of jumpamine....."
Report ALL data, even if it was unexpected or if it did not support your hypothesis. Include data for any pilot experiments. Types of data will include:
- General observations made during the experiments
- Quantitative results (summarized as means, standard deviations etc.), which normally appear in figures and/or tables
- The results of statistical analyses. This can be done in the text if it is simple. If there are many numbers, put the data in a table.
Reporting of statistical analyses:
Statistical analyses are frequently done poorly in lab reports. In the text, go straight to the important point(s).
- Good Example:
The mean weight of plants grown under white light was greater than the mean weight of plants grown under green or red light as seen in Fig. 1. The difference between means was significant (p = 0.052), as seen in Table 1.
- Bad Example:
The mean weight of plants grown in Treatment 1 was 27grams. The mean weight of plants grown in Treatment 2 was 19 grams. The variance was 99.1343. The T value was 3.1384. The df was calculated to be 12. The p was 0.04, so the probability that the results were to to chance was less than 5%. All the data and t-tests can be seen in Figure 1 and Table 1.
Problems with the bad example:
- MUCH too detailed and wordy; for most of this information, the reader can be directed to the figure and table.
- Great precision is implied by the number 3.1384; round off to 3.14 or even 3.1
- The reader probably has forgotton what "treatment 1" and "treatment 2" are; use meaningful labels that the reader does not have translate by referring to previous pages.
- You do not need to define what "p" means, and it is redundant to do so (it is defined as the probability that the results are due to chance); readers of scientific literature are familiar with the term.
Do NOT discuss the implications of the results in this section, nor attempt to explain why various results occurred.
Most of the DETAILS of the results will occur only in figures or tables. Only the important points of each figure and table should be described paragraph format; don't reiterate the whole figure.
RAW DATA is NOT normally reported in the Results. Readers are usually interested only in SUMMARIZED DATA, such as means, standard deviations, totals, etc. However, since this is not really going to be submitted for publication, you should include any raw data and lengthy calculations in an APPENDIX so your instructor can detect any errors you may have made.
This is usually the most important part of your paper. This is your chance to be original, cleverly interpret the results you obtained and draw general conclusions from them. Information in the discussion should go from the specific to the general. This is a typical order of topics which might occur in the Discussion:
major conclusions (don't list this as a subheading)
Begin the discussion by briefly stating the major conclusions from the results. Explain what the results mean. Discuss whether the results SUPPORT or do NOT support your original hypothesis(es). Your experiment is really very limited in scope, so DO NOT claim that you have "proven" or "disproven" a hypothesis; you perhaps obtained some small bit of evidence to support a hypothesis, or you provided some evidence which contradicts a hypothesis.
expand on your results
In next paragraph(s) expand your discussion of these results. You might wish to compare them to results from other studies, which you should cite properly.
introduce some new ideas
As the discussion continues it is important to offer some original ideas and interpretations. For example, discuss the implications or your results for the biology of the organism(s). For example, why did the behaviors you observe evolve? You may wish to suggest new experiments which would shed further light on the questions raised by your results.
improvements in experimental design
Your best guess is that the results reflect reality. Students often feel that their discussion should consist mainly of an analysis of all the things that went wrong with the experiment. We strongly discourage this approach. Naturally all experiments have some weaknesses, but for the purposes of this exercise assume that your results are reasonable. It is OK to get negative results (no significant differences). You may, however, suggest additional experiments using different methods that may improve our understanding of the topic.
In this section you will list any literature which you have cited in the text. List ONLY those references which you have specifically cited. References are listed in alphabetical order, by the first letter of the first author's last name .
FREQUENT PROBLEMS IN SCIENTIFIC WRITING
The following are a few hints to better scientific writing. Read them carefully.
- Underline or italicize scientific names. The genus should be capitalized and the species name lower case (unless it's a proper name). The word "species" is both singular and plural; there is no word specie'. The plural for "genus" is "genera"
- Be concise by eliminating unnecessary words. Some examples:
In his paper on spiders, Jones stated that spiders can't fly (Jones, 1950).
In order to conduct the experiment we used 10 test fish.
The bold faced words in the above examples can all be eliminated.
- Use the standard scientific citation format:
Smith (1987) found...
Eagles eat turtles (Smith, 1987) ...
- The cited articles should be listed in alphabetical order at the end of the paper under "Literature Cited."
- In general, DON'T use quotes.
Instead, paraphrase the author and cite him/her. Quotes interrupt the flow of your text. Only quote if the precise wording is absolutely critical. If you must quote, incorporate 2-3 lines into the text. Longer quotes should be isolated by single spacing and wider margins.
- If an entire paragraph comes from a certain author, cite once at the end of that paragraph, not after every thought or sentence.
- Scientific writing is formal communication. Don't use conversational language, colloquialisms or slang.
- Read your paper out loud, or, better, have a friend read it to you. This helps with the placement of commas (at pauses) and points out awkward phrases or sentences.
Some frequently misused/misspelled words:
The effect of their misuse will be that your grade will be affected by subtracting five points.
"Effect" is a noun (usually).
"Affect" is always a verb.
"It's" is the conjunction "it is".
"Its" is the possessive, and possessive pronouns don't have apostrophes. e. g. hers/his/ theirs.
I assume this is just carelessness, but it happens too often.
Between refers to two things, while among refers to more than two.
Use "fewer" if you can count the items, "less" if you can't. e.g. less water, but fewer boats.
Use 'amount" if you can't count them, "number" if you can. e.g. The amount of sand and the number of rocks
Drop the "times"; it's redundant.
- different from / different than
Different from is correct; different than is not.
- than/then -- each of these is sometimes used when the student means to use the other; proofread!
This is commonly misspelled (there is no a in this word).
These words should almost never be used in a biology lab report. Your experiment is very limited in scope and will only provide evidence for or against a hypothesis.
- Use parallel constructions in a series. e.g. The dog likes to run, play and bark. NOT The dog likes to run, play, and he barks too.
- Always put a zero in front of a naked decimal point (0.12, not .12).
- Species is both plural and singular
For questions or comments, email to Paul Willing: firstname.lastname@example.orgLast Revised 3/19/02