Some portions modified from NCSU’s LabWrite program: http://labwrite.ncsu.edu
So you have conducted an experiment, have buckets of data, and have given things some thought. It is now time to communicate the results of your experiment. Formal lab reports are important (labs count for as much in your course average as exams do), and there are certain expectations that you should follow when you write one for AP Biology.
In AP Biology, we will use the IMRaD format when writing lab reports. IMRaD (Introduction, Methods, Results, and Discussion), is a standard format for reporting the results of experiments in the scientific community. This document explains the specific details of our IMRaD lab reports. It is important that you read this document fully, and ask any questions that you have prior to submitting your first AP Biology Lab Report.
Table of Contents:
The following table of contents is provided to help you navigate the document:
Generally, you will be given several weeks to work on a formal lab report at the conclusion of a lab experience. This is both because I am a gracious soul, and because I fully expect that the document that you will submit will be evidence of your best possible effort. To that end, there are a few, basic things that you should make sure you have done prior to submitting the lab:
All labs in this course are to be submitted to me via google docs. You must create them in Google Docs on the Deer Park Google Apps Portal. This process must be specifically adhered to. There are several things that you must make sure you do when submitting your lab:
ANY LAB THAT DOES NOT FOLLOW THESE GUIDELINES WILL NOT BE COUNTED AS SUBMITTED, AND MAY BE PENALIZED FOR LATENESS (10 POINTS/DAY) ACCORDINGLY.
Not a section, per se, but it should be mentioned. At the top of your page, you should give your report an appropriate title . “Appropriate” means that it is related to the investigation that you conducted, and the variable that you manipulated. So a title like “Brine Shrimp” is not acceptable. A title like “The Effect of Salinity on Brine Shrimp Hatching Rate” is just about perfect. As always, I love a bit of humor, so if you want to go with something like “The Law of The Briny Deep: Brine Shrimp Hatch Rate as a Function of Salinity”, it’s totally fine. But the bottom line is that we put this:
The Effect of INDEPENDENT VARIABLE on DEPENDENT VARIABLE.
Or a variation therein somewhere in the title.
The introduction section for your report should include the following sub-sections. These can be individually delineated, or cohesively integrated, as per your preference:
In this section of the lab report, you will provide the reader with background information that will use to help them understand the experiment you have done. The introduction should also inform the reader about the underlying biological concept of the lab. This section should include any unfamiliar terms that might be used to clarify ideas for the reader, particularly ones that you are going to use later on in your report. You are going to want to cite information from somewhere other than your own brain, and as such, you should include the sources you have cited here in your reference section at the end of the lab. Do not forget to include in-text citations in this section, where appropriate.
You will always need to list what the objectives of the lab experiment are. Why did you do this lab? What was the point. I’ll give you something that should clue you in, in the material that I provide you with for each lab (which can be cited as per the previous section), but the demonstration of independent thinking is always appreciated. Bullet points are fine to use here if it helps you frame your thinking.
In this section, you will formulate a testable question that addresses a problem. This problem can either be one your teacher assigns, or one you devise on your own. You will also establish what you think will happen during the lab. Your hypothesis should be testable. You should identify your dependent and independent variables. While I won’t take points off if you have to use the “if, then” format, I won’t be super psyched about it, either. After stating your hypothesis, you should include a few sentences explaining why you think your hypothesis is what it is. In other words, don’t just state your hypothesis and move on, put some thought in to a justification of why your hypothesis is a reasonable one.
The Methods section for your report should include the following sub-sections. These can be individually delineated, or cohesively integrated, as per your preference:
A complete list of the supplies used during the experiment should be given. Be as specific as possible. Include the volumes of tubes and cylinders. If organisms are used, scientific names (Genus species) must be provided. If chemical reagents are used, concentrations of these reagents must be given, if known. Include the model and manufacturer of any complex apparatus.
This section should outline exactly what steps were taken to conduct the experiment and should be written in in third person past tense. Do not use “I.” This section should be concise and describe exactly what was done during the experiment. In this section, you should also clearly identify your independent and dependent variables, as well as your control treatment (if there is one) and your constants. Generally speaking:
This section should be written in sequential order (numbered steps are fine). If you did not design the procedure yourself, you do not write up this section of the lab, you can simply reference the document that you took your procedure from (citations strike again). Similarly, if you adapted your procedure from another protocol, you can say as much and then delineate how you have adapted the procedure for your purposes:
Make sure that your procedure is detailed enough so that another person could repeat your work by reading your report. Your procedure should speak to validity measures. Validity measures are things kept constant to make sure experimental measurements are valid and consistent (ex. cleaning test tubes prior to use, cleaning the microscope lenses, using the same ruler…). Your procedure must clearly state how you collected data:
If you will be combining data with data collected by other students in the class, you should indicate that explicitly in your procedure and explain why this pooling of data was done. If you are sampling only a portion of a population, you must explain how and why you ensured that the sample was randomly selected.
Your procedure must be safe and ethical. Organisms, including humans, can not be subject to harm in your investigation. List any safety precautions that were taken during the lab.
The results section is evaluated according to two separate criteria.
Your data section will include your raw data gathered during the lab. This should include both qualitative and quantitative data (both need to be present):
Degrees of precision:
It is important to be aware of the precision of the measuring instruments that we use. Generally the accepted rule is that the degree of precision is ± the smallest division on the instrument. Let’s look at an example using a ruler, graduated in millimetres, to measure the length of a leaf. You will probably find the edges of the leaf lie close to a millimetre division but probably not right on it. Recording the leaf is "4.5cm-and-a-bit" long is not very useful. So the length of the leaf in this example is recorded as 4.5cm ± 0.1cm. The degree of precision will influence the instrument that you choose to make a measurement. For example if you used the same ruler to measure an object 0.5cm long the degree of precision (± 0.1cm) is 20% of the measurement, this is very large error margin and, so, it is not very precise. Therefore, we must choose an appropriate instrument for measuring. Use this understanding when conducting and recording measurements in lab.
All lab reports must include at least one graphical representation of your data and two data tables (processed data should always go here. A raw data table should be included here or provided in an appendix for the lab depending on how extensive it is). Additionally, all calculations need to be shown in this data section. All items in this section should have a one-sentence explanation of what is being shown. Label all graphs, drawings, and images as figures in numerical order (ex: figure 1, figure 2, etc.). Do the same for tables, though number them separately from figures (ex: table 1, table 2, etc.). For each graph or table you construct, provide a brief description of the data trend the graph or table shows. For example, if a graph clearly shows a negative correlation between two variables, give a brief statement about the trend underneath that graph. If drawings/photographs are included, they should be clearly labeled and accurately representative of what you are depicting. Clarity is important!
Tables should be organized, and informative. Units should be used wherever possible. Here are some items to keep in mind when constructing data tables:
Graphs should be generated on a computer program/website of your choosing, and adhere to all proper graphing techniques. The trend being shown in your graph should be clear and not obscured by poor design choices. Here are some items to keep in mind when deciding how to represent graphs:
Drawings and images are considered to be lab data. Unlike tables and graphical representations, not all labs require drawings/images (though they are acceptable in all lab reports). Here are some items to keep in mind when deciding how to represent drawings and images:
Statistics are useful mathematical tools which are used to analyze data. Common statistics used in biology are:
For each statistic you calculate, you must explain why you elected to do that calculation. What does the calculation tell you about the data?
Show an example calcualtion for each statistic you calculate. Given the nature of electronic word processing programs, it is strongly recommended that you use an equation editor to render equations and calculations (links to several equation editors are provided in the references for this document). Show the units of measurements in all calculations. Pay attention to the number of digits! Don’t lose accuracy by carelessly rounding off. Round only at the end of a calculation. Do not truncate. Present your data processing results in a table. The initial raw data and the processed (calculated) data may be shown in one table provided they are clearly distinguishable. Be sure your processed data table adheres to all table guidelines mentioned above.
The methods section for your report should include the following sub-sections. These can be individually delineated, or cohesively integrated, as per your preference:
The conclusion section of the lab is where you explain and analyze your results, relate the experiment to course concepts, discuss potential limitations to the activity you did, note any errors made, and provide suggestions for improvement or future study. The following questions will help guide you in writing the conclusion section for any of our lab activities. Do not address these questions individually (or even in total), but use them to construct your narrative:
Additionally, you may find useful items for discussion in the materials that you are provided with when conducting a particular lab. If possible, cite literature related to your conclusion. Does you result coincide with published results? Does it refute published results?
For every lab, you will need to evaluate your procedure, how you thought it would work compared to how it actually worked, how you could improve/refine the procedure and generally what you could do in the future to have a better lab experience. This section should also include a discussion of sources of error in your lab. The following questions will help guide you in writing the experimental evaluation for any of our lab activities. Do not address these questions individually (or even in total), but use them to construct your narrative:
Additionally, you may find useful items for discussion in the materials that you are provided with when conducting a particular lab. Do not be incomplete in your response in this section. Do not use vague or nonspecific language. Be precise and complete!
All lab reports should adhere to stylistic conventions of either the APA or IEEE (preferred) editorial style. If you are unclear about how these stylistic conventions apply (both in terms of a reference list, AND in-text citations), I encourage you to consult the references provided below. Wikipedia should never be used as the sole source for any aspect of a lab report.
If you choose to include appendices (for raw data, perhaps), they should come after the reference section and be presented in lettered order (ex: Appendix A, Appendix B, etc).
Obviously, there is no such thing as “correct length” for a lab report. At the same time, it might be suggested that since these documents are the result of weeks of effort, and given what is required in them, there are certain benchmarks that should sound an alarm if they are not close to being met for particular sections. To that end, I would expect that the Introduction would be at least a page, and that the Discussion sections would be at least two pages (they could easily be much longer). Materials and Results will vary in length considerably from lab to lab, and as per the decisions made by the author(s). Again, I wish to stress that these are guidelines and not hard rules.
The following specifically applies to independently written lab reports. To be clear: the following aspects of a lab report are allowed to be similar/identical among members of the same group:
All other work must be independently generated. While groups are encouraged to work together, the work that is submitted must be original enough to not be demonstrated to be identical when subjected to computational similarity analysis (ex. via turnitin.com). Plagiarism considerations are likewise noted (all non-original work and words must be cited).
As part of your grade, your lab notebook will be checked to verify the accuracy and quality of the data that you are taking during laboratory activities. The caliber of this data is accounted for in scoring the lab, typically as a grade multiplier outside of the main categories.
This document is intended as a guide, not as a “no exceptions” use case. The particular details of any one lab report may change from what is described above, in some cases significantly so. In all instances, the specific details and requirements for any lab report will be discussed with the class, and a forum posting for the lab will be available to track any changes to the report that will be produced/provide help with writing the report. Any details/alterations to a specific lab report take precedence over the guidelines explained above.
The following references may be helpful for particular aspects of your lab report writing:
LabWrite Lab Report Help:
Wikipedia IMRAD format Page:
General Graphing Primer (also contains a lot of other information about the lab report process):
Making Graphs (aka “Charts”) in Google Docs Spreadsheets:
Plot.ly: Robust Online Graphing Tool (my preferred online graphing tool):
Using the Google Chart API directly (no spreadsheet required- 2 different sites):
Create-A-Graph Graph Construction Website:
Editing equations on a computer can be a bit tricky to learn. As you probably know, trying to format an equation in a document is almost impossible (at least if you want it to look good). On computers, all equations are basically handled by a markup language called LaTeX, which is really powerful, but also a bit tricky to learn. Fortunately, there are a variety of visual editors that you can use to help you make your equations, but you are going to make a few mistakes before you “get” the logic that works under these systems. Google Docs has an in-program editor (available in the view menu) which is based on LaTeX, but is a bit simplified.
Using the Google Docs Equation Editor:
There are some nice visual equation editors that use full LaTeX scripting (you would export these equations as .png files and then import them into your lab report). Here are two that are pretty easy to use:
(does not do IEEE style citations):
Provided below are the criteria that are considered when grading a lab report. Not all criteria are given equal consideration when scoring a lab.
Introduction: Background and Objectives
•Introduction is thorough, connecting the material of the course to the activity of the lab.
•The introduction provides the reader with key terms.
•Appropriate, properly formatted citations are provided.
•The underlying biological concept of the lab mentioned and is clearly explained.
Research Question/ Hypothesis
• Research Question is stated
• Rationale is provided for question.
• Testable Hypothesis is stated and is justified.
• Independent and dependent variables are explicitly identified.
• Materials list is complete (according to lab report guidelines).
• Concentration of chemical reagents used (when known), scientific names of organisms are named, volumes of apparatus, etc. are provided.
• Procedure is concisely written using third person past tense.
• There is an acceptable range of variance in the independent variable.
• Constants are clearly identified.
• Control group is identified.
• Labeled Diagram or photo is provided.
• Validity measures are addressed.
• The procedure allows for the collection of “sufficient relevant data”
• The protocol states that data will be combined (if necessary).
• Procedure is safe and ethical.
• At least one, properly formatted citation is provided.
• Raw data is recorded.
• Processed data is recorded.
• Both quantitative data and qualitative data are recorded.
• Data adheres to precision guidelines.
• Units are present on quantitative data.
• Report includes at least one graph and two data tables (raw data and processed data)
• All tables, graphs, drawings, and calculations adhere to lab report guidelines
• Relevant statistical analysis of data is demonstrated.
• Calculations are clearly demonstrated.
• All elements in the data section are explained with at least one descriptive sentence.
• Conclusion is based on reasonable interpretation of data.
• Clear connection is made between hypothesis and data collected.
• Clear connection is made between the lab activity and the understandings of the course.
• Discussion of limitations of the experiment is provided.
• Discussion of unexpected results is provided (when applicable).
• Applicability of the conclusions of this experiment to other situations is provided.
• Statement of confidence in the experiment is provided and justified.
• Measures to ensure validity are discussed.
• Recommendations for refining the experiment are provided.
• Identification and discussion of sources of error is provided.
• Specific recommendations to address identified weaknesses are provided.
• Suggestions for future avenues of research are provided.
• Report demonstrates proper spelling, grammar, and consistent design considerations (formatting, spacing, etc.)
• Report adheres to APA or IEE citation conventions in-text and in the reference section.
• Report is shared correctly, posted publicly on course blog correctly, and posted in a timely fashion.
Lab Notebook Data Verification: The quality and accuracy of your lab data serves as a score multiplier for your overall grade, ranging from .9 at the low end, to 1.1 at the high end. In other words, if you keep poor records, it can cost you up to 10% of your total grade earned. Likewise, keeping exemplary records in your lab notebook can earn you an additional 10% on your score.
By David Knuffke, adapted from documents by Lee Ferguson and Richard Kurtz