1. Title: What is the name of your experiment?
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. A good guideline for a title is to use the following:
The Effect of INDEPENDENT VARIABLE on DEPENDENT VARIABLE.
2. Abstract: Summary of Lab
In this section, you should provide brief background information, state the purpose of the lab, briefly describe the methods you employed, briefly describe results and state conclusion. This should be a short summary of everything that you include in the lab. It is intended to be a “snapshot” of the entire paper.
3. Introduction: Establishing a context for the lab
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.
4. Research Question, Explanatory Hypothesis and Related Prediction
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. Your hypothesis should be testable. You should identify your dependent and independent variables. After stating your hypothesis, you should include a few sentences explaining why you think your hypothesis is what it is.
5. Materials: What equipment, organisms, or reagents did you use?
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 (Homo sapiens) must be provided. If chemical reagents are used, concentrations of these reagents must be given, if known.
6. Procedure: How was the experiment conducted?
This section should outline exactly what steps were taken to conduct the experiment and should be written 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 control treatment and your controlled variables.
The data section is evaluated according to two separate criteria.
- Data Collection: What information have you gathered?
Your data section will include your raw data gathered during the lab. This should include both quantitative and qualitative data collection (both need to be present). Qualitative data can include descriptions and photographs or sketches, which must be in color since we are often working with living materials.
Tables should be organized, and informative. Units should be used wherever possible. Here are some items to keep in mind when constructing data tables:
- The table is easy to understand
- The table has a specific title
- The table has column headings
- The table includes the unit of measurement (always in metric units)
- The table includes the measurement uncertainty of the measurement tools used (or, if the data was a count, indicates that “counts have no measurable uncertainty”).
- Uncertainly is usually stated in a column heading or as a footnote at the bottom of the table.
- The table has a consistent and correct number of digits for each measurement
- The table has decimal points aligning down a column (if applicable) and numbers centered in the column
- The table indicates which data was collected by which student IF the data was collected and pooled across multiple students.
Graphs should be hand generated on graph paper, 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:
- Use the correct type of graph for the type of data you are presenting.
- Graphs need to have appropriate scales, labeled axes with units, and accurately plotted data points.
- If necessary, add smooth lines or curves to show the overall trend of the data.
- If a mean is calculated, only graph the mean, not all data points. When a mean is graphed, its associated standard deviation error bar must also be included (and labeled as such).
- Legends (keys) are not always necessary, but should be used whenever more than one trend line is graphed on a common set of axes.
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:
- Include labels written off straight, horizontal lines to the right of the side of the drawing. The labels should form a vertical list.
- Be accurate. Draw what you see; as you see it, not what you imagine should be there.
- Include a title that states what is being shown and what lens power (if any) it was drawn under. The title must be informative, centered, and larger than other text.
- Include a scale that indicates how many times larger the drawing is compared to life size and a scale line that indicates relative size.
9. Experimental Evaluation:
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:
- In general, how much confidence do you have in your results. If you did a hypothesis test, make sure to state your answer in terms of the percentage that the hypothesis test determined.
- Why do you feel confident (or not confident) in your results?
- What did you do to ensure validity?
- Looking back on the lab, is there anything that you, your group, or the class could have done differently? Be detailed in your recommendations.
- Discuss the sources of error in the lab, why/how they contributed to errors, and what could be done (if anything) to address those sources of error. Here are some of the more common sources of error seen in labs:
- Human error: Human error can occur when tools or instruments are used or read incorrectly. Human errors can be systematic because the experimenter does not know how to use the apparatus properly or they can be random because the power of concentration of the experimenter is fading. Automated measuring using a data- logger system can help reduce the likelihood of this error; alternatively you can take a break from measuring from time to time.
- Calibration error: Some instruments need calibrating before you use them. If this is done incorrectly it can increase the risk of systematic error.
- Random errors: In biological investigations, the changes in the material used or the conditions in which they are carried out can cause a lot of errors. Biological material is notably variable.
- The act of measuring: Could the measurement uncertainty have affected the results? Why or why not?
- Uncontrolled variables: What variables were not controlled? What effect might each of these uncontrolled variables have had on your data? On the conclusion?
- How could the lab be changed or modified to provide more accurate data or to measure other aspects than what was measured? What improvements could be made? How could the weaknesses identified be improved?
- What are some of the areas of future or expanded investigation that might be worth looking at?
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!