Lab report Procedure and Requirements

A scientific paper is an important method of communication.  Therefore, the paper must be well organized and concisely written.  A lab report is no different from a published report in a scientific journal.  Although each journal has its own requirements and stylistic techniques, in this assignment we will use examples of those required specifically for a high school Biology class.


The purpose of doing the investigation is very important.  In this section, you will summarize what you already know about the project, as well as indicate the reason for doing this particular experiment.  The purpose is best written in the past tense with passive voice.  It must follow a logical pattern of reasoning, so organization of the information before this section is written is important.  General statements related to the topic are presented first, and as the narration continues, the statements become more specific.  The progression from general to specific helps the reader to “focus in” on the hypothesis or the problem.  The terminating statements should precisely define the problem being investigated.  The variable, measurements that will be made, and/or organisms studied are identified.  An example of a “purpose” section for a lab report follows:
Photosynthesis is an important process not only for plants, but for all living things.  In this process, carbon dioxide and water are used in conjunction with light energy to create a substance that stores energy in its bonds, as well as oxygen as a byproduct.  The rate of photosynthesis varies with several factors, among them the amount of carbon dioxide present, the light, and the type of organism.  In this investigation, we will investigate the rate of photosynthesis in the water plant Allium.  Temperature and the amount of carbon dioxide will remain constant, but the amount of light will vary.  The rate of oxygen produced will indicate the rate of photosynthesis.  This rate will be measured by counting the bubbles evolved from a cut stem of Allium during a specific time interval.


The procedure or methods section describes the materials needed and the experimental procedure.  It is NOT a list of materials, then a numbered list of steps.  The materials are NOT listed independently, but are identified within the description of the experimental procedure.  The procedure must be concisely describe in sufficient detail that it might be duplicated.  During the course of the experiment, careful recording should be made of everything that is done, so that it may be replicated in this section.  The procedure is written in past tense with a passive voice, and follows a chronological sequence.  The specific variables, controls, organisms, parameters, time frames and any other pertinent information are given in the experimental directions.  The terminating sentence should indicate how the results or data will be interpreted.  An example of a procedure section follows:
Cuttings of Allium containing growing new leaves were placed into test tubes, with the stem upward, along with a calcium carbonate solution that would maintain a constant high carbon dioxide availability.  Temperature of the cuttings was maintained at room ambient temperature.  Two test tubes with Allium were set aside as a control.  Two were exposed to increased light, in the form of a 60 watt bulb at a distance of 20 cm from the test tubes.  Oxygen production from the plants was measured in the form of bubbles coming from the stems.  The rate of oxygen production was measured every minute, for a period of time of ten minutes.  This bubble production will be analyzed to directly determine the importance of light intensity to rate of photosynthesis.


The results or observations section includes data collected and observations made during the experiment.  The data may be represented as tables or figures, but some narrative must be included.  Each table or figure must be described and explained.  Comments should be offered that will contribute to the reader’s understanding and interpretation of the data.  The narration of the results section is written in the past tense.  Specific data should be used in chronological order to focus the reader on unusual or significant data.


In the conclusions section, the data from the results are interpreted.  What the results indicate, what relationships or patterns exist are shown.  The investigator also compares his or her results to those that were expected or those that were obtained  in previous experiments.  This section commonly follows an inductive line of reasoning.  A discussion of the specific, significant data is presented, and the section is terminated with a general conclusion.  An example of a conclusion section follows:
In this investigation, it was seen that both of the experimental Allium plants increased their production of oxygen bubbles by 50 percent with an increase of light exposure for a ten minute period. Photosynthesis rates increase with increased light intensity.  This may be of value and importance for those plants that exist in different climates and locations.

Your lab report should represent your best efforts.  It should be completed neatly and have numbered pages.  Do not start a separate page for each section.  Instead, each section should immediately follow the end of the previous section.  Proofread your entire paper for errors.  Make it look as professional as possible!

Lab report example.