Lab Reports
Your lab reports will be short and sweet. Another word for this is concise. Six sections complete your write-up: 1. Purpose: What are you investigating? 2. Hypothesis: Written as an if..., then... statement. Please include the change in your independent variable for the “if” part, and the dependent variable response in the “then” part. Example: If the color of the jar is changed from white to black and allowed to stand in the sun 10 minutes, then the temperature inside the jar will rise compared to the control. 3. Materials: A list of materials used is sufficient. 4. Procedure: Briefly explain what you did as well as tell me what variables you kept constant, what variable was changed (independent variable) and how, and what you measured or observed (dependent variable). 5. Results: Please use well labeled tables and graphs if applicable. Make sure all your data is presented. 6. Conclusion: The hypothesis is (correct, incorrect) because______________. To investigate this further I would _____________.
Voice in your report: Lab reports are written in passive voice because the experiment, not the person, is central. “ I” is never used. This is far different than an English paper. Do not use passive voice in your English assignments. Here are 2 examples: Active voice: I wrote an essay. Passive voice: An essay was written. Active voice: I used a triple beam balance to find the mass of the object. Passive voice: A triple beam balance was used to find the mass of the object.
Finally, please make sure your name and date are on the Lab Report. Reports may be handwritten or typed.
An example Lab Report is on the second page.
Name: Mrs. Kowalski Date: 9/9/12
Purpose: This experiment investigates how much water 3 brands of paper towel absorb. Hypothesis: If each brand of paper towel is allowed to soak up water for 10 seconds, then the Brawny will soak up the most as measured by the amount of water squeezed from each towel. Materials: Brawny, Bounty, and Awesome paper towels 50 ml graduated cylinder funnel bowl of water Procedure: Five paper towels of three brands were cut to the same size to keep the surface area constant between all test subjects. Each paper towel was immersed in water for 10 seconds, allowed to drain for 10 seconds, and the remaining water squeezed into a graduate cylinder. A funnel was used to collect the water into the cylinder. The volume of water collected from each paper towel was tabulated. Results:
Amount of water (ml) Trials Average amount
Type of Paper Towel
1
Bounty
33
30
32
31
34
32
Brawny
28
30
29
27
27
28
Awesome
23
24
22
23
24
23
2
3
4
5
of water (ml)
Conclusion: According to this experiment the hypothesis is incorrect because the Bounty absorbed more water than the Brawny, 32 ml and 28 ml, respectively. To investigate this experiment further, the weight of each paper towel should be measured so that the amount of absorbing material is compared and not just the surface area. Then the experiment should be repeated. Also, the cost per square yard could be compared to the absorbing power of the towel for an economical analysis.
