AP/IB BIOLOGY – LABORATORY FORMAT
All biology labs will be written in the lab composition book while doing the lab. The first page of the book should be reserved for the table of contents. Every lab must be listed in the table of contents with the page number on which it starts. Your lab reports will be typed.
The following titles and subtitles should be used for your lab report and given in this order.
DESIGN
Question – must be focused and not ambiguous in any way. If a living organism was used, identify it by common name and scientific name. Include research you did leading you to your question. Don’t forget to cite your sources.
Hypothesis statement
A hypothesis should propose a relationship between two or more variables and should be quantitative, if possible. A typical format of a hypothesis statement is “if …(proposed explanation), and … (what you did), then … (expected results)”.
Variables
Create a chart or list identifying the IV, DV, and controlled variables. Be specific; room conditions is not acceptable. Explain why the independent and dependent variables were chosen.
Protocol Diagram
Draw and label a diagram which best shows the major protocol(s) you used. Often this will focus on the technique that was used to measure the dependent variable and/or the technique that was used to ‘set up’ different increments of the independent variable. Be sure to show how the control group(s) differ from experimental group(s). This is also where I want you to emphasize the inclusion of a period of time for ‘equilibration’ of equipment, fluids, organisms, etc. The inclusion of time periods for equilibration should also be included in your written procedure.
Photograph of Lab Setup
When your lab is completely set up, take a digital photograph. Annotate this photo to show how variables were instituted, especially the controlled variables. Do not just label equipment. This is the section that I use to decide if your procedure properly controls the variables you have identified in a chart or list earlier.
Methods
Write the procedure out in steps, passive voice, past tense. Detail should allow repeatability. You should ensure that your procedure includes at least 5 levels of the independent variable (i.e., 5 temps, 5 pH’s, 5 concentrations) and also includes a minimum of 5 repeats (trials). You must also collect some data that is qualitative. Please indicate measurement of controlled variables.
DATA COLLECTION AND PROCESSING
Raw Data
Present your results in an organized, clear fashion. Use charts and drawings when appropriate and be sure labels and units are clearly indicated. Drawings should be labeled with the magnification and/or view. Every drawing, table or graph needs a specific title. Make sure all columns, etc. are properly headed and units are given. Forgetting one unit or misidentifying one unit is enough to drop your score in this section. Do not split a table onto two pages. Be consistent in the number of digits used when reporting data (appropriate precision). Uncertainties are mandatory and can be given within column headings for equipment precision and as footnotes beneath data tables for other types of uncertainties.
Data Processing and Presentation
This is typically one or more data tables (of your now processed data) and one or more graphs of the processed data. Once again, the design and clarity of data table(s) is important and the quality of graphs is also very important. Give careful consideration to the choice of graph style(s) that you choose. Remember that demonstrating errors and uncertainties is also mandatory in processed data. Plotting best fit lines with error bars is a good way to show uncertainties in processed data. Make sure you follow good standard rules for doing graphs (valid title, axes labeled with variable and unit, appropriate range for scale). Data processing may also include diagrams, maps, or statistics. Neatly lay out and explain one example only of any type of calculation that was done to raw data.
Note: Weak experimental design can sometimes limit you to pie graphs and/or bar graphs.
Avoid this by good experimental design in which you have a quantitative independent variable
(with well chosen incremental values) as well as a quantitative dependent variable.
CONCLUSION AND EVALUATION
Conclusion
Interpret the data and come to conclusions. Start by addressing whether your data seems to support or refute the hypothesis (use of statistics is helpful). this should be discussed and not just stated. Specifically refer to your graphs to give support to this discussion. Avoid use of the word ‘proof’ or ‘proves’ within your conclusion, as your data will not prove anything. Base your conclusions on the data and research of the topic of the experiment. Look for trends in the data to guide you.
Limitations of Experimental Design
In this section, discuss how well the experimental design helped answer the original question. What worked well (and why) and what did not work well (and why)? This is also the section in which outlier points could be discussed (if there were any outlier points), as well as possible reasons for those outlier points. If you did a statistical test, what did the results of that test show? If you have error bars on your graph(s), what do those show? Remember to relate all of this to your design.
Suggestions for Improvement
In reference to the limitations and weaknesses given in the previous subsection, what realistic and useful improvements could be made if you were to do this investigation again? Both the limitations and the suggestions for improvement must show good reflective thinking. If you simply list a few obvious ‘flaws’ without good consideration of their relative importance, or if you ignore obvious ‘flaws’, then do not expect to score well.