Experimental Design Plan
For your course project you are tasked with designing a
Experimental Design Plan
For your course project you are tasked with designing and carrying out a research project on plant transpiration of your own design using the Vernier instruments (see attached Transpiration Lab Student Guide for directions).
Transpiration is the process by which moisture moves through a plant. The process is broken down and explained in chapter 30, section 30.5 of the text book. The purpose of this assignment is to help you plan and design an experiment investigating the factors that impact plant transpiration.
Today’s experiment is all about planning. You will not actually conduct the experiment until during (or before if you choose) Week 14. However, after this week’s assignment is complete, you will be well organized and prepared to conduct your experiment, collect data, and conduct the experiment analysis.
During week 14 you will submit an experiment report using information from your design plan as well as your experiment results.
Please note that experiments that do not use the Vernier sensors will receive a grade of 0 so make sure you have your sensors ordered and available by week 14 when you must turn in your experiment report. See Content > Course Materials for ordering information.
LAB SAFETY NOTES:
You will be using a sharp object to cut the stem of your plant. Please take appropriate care and caution.
Do not cut any plant stems you cannot identify to avoid allergic reactions.
The Experimental Design Plan assignment is Due Week 6.
Submit the attached experiment design sheet with answers as an attachment.
*Note: additional instructions for determining leaf surface area by hand have been added to the documents for this week’s assignment.
Instructions:
Look through the directions in the transpiration lab student guides. Before performing an experiment or lab, you must design and plan what is going to be tested and how you are going to test it. You must be organized and be able to communicate your results effectively. This assignment is designed to help you organize your experiment design. Use what you have learned about the scientific method from your lab assignments to help you design an experiment on plant transpiration. You will need to conduct some background research on plant transpiration to help you design your experiment. The research will be used to help you write the introduction portion of your experiment paper.
An experiment is a research method in which you manipulate a variable or variables under very controlled conditions and examines whether any changes occur in response to the manipulation of the variable.
It is a cause and effect relationship
1. Experiment introduction & background research with references in APA format (50 pts)
Before you can design an experiment you need to have a good understanding of the current research. You need to summarize what research is currently known about your experiment question in the introduction of your report. This part of the assignment allows you to get a jump start on that task while building valuable knowledge that will help you in your experiment design.
1) Visit the APUS library and internet to research information on plant transpiration. The program guide for natural sciences is a good starting place to begin your APUS library research: Natural Science
2) Look through these tips for how to share background research in an introduction: Tips for Introduction section
Collect background information for your research experiment and use references and in-text citations to back up you research. (In science writing, almost every sentence is cited. Make sure you cite your sources!!)
Explain any ideas or techniques that are necessary for someone to understand your experiment. At the minimum you should cover what transpiration is, what role/influence your independent variable has on enzymes, why this is important, your testable question and hypothesis. The introduction is generally 1 page long. You need to use APA formatted in-text citations and references and this should be written in the 3rd person. You need to use at least 4 different academic references for your background research.
The grading in this section of the assignment is broken down as follows:
Coverage of topic including scientific question and hypothesis: 30 points
4 academic references and APA reference and citation technique: 15 points
Grammar/spelling/voice:5 points
Need tips on APA in text citations? They can be found here: In Text Citation
Need tips on APA reference formatting? They can be found here: Reference List
Want a handy tool that formats your references in APA for you? Visit this website: KnightCite
2. Identify the Independent Variable, Dependent Variable and Constants (10pts)
Independent Variable is the variable that is manipulated. It is the variable that you change on purpose. (The CAUSE) There are many variables that can change transpiration. You will choose only 1 independent variable to test. You can choose from temperature, light, humidity, plant species, or air flow.
Dependent Variable is the variable that we measure in response to the manipulation of the independent variable. It is a measurable change. State what are we measuring to gauge transpiration in our experiment here(The EFFECT)
Constants are all the other variables in the experiment that must remain the same so we can see what effect the independent variable has on the dependent variable.
The Control is used as a standard of comparison. The control is a level of the independent variable that has been changed the least or not at all.
3. Write a Title (5pts)
Use the following pattern when writing a title…
The Effect of the (Independent Variable) on the (Dependent Variable)
4. Write a Testable Question (5pts)
Not all questions are testable!!
A testable question asks. . .
“What is the effect of the Independent Variable on the Dependent Variable?”
5. Write a Hypothesis (5pts)
A hypothesis is a prediction of the outcome of the lab. Your prediction is based on your understanding of the scientific concept.
It answers your testable question. Use the following pattern:
IF the (IV- how it is changing), then the DV- how you think it will change), BECAUSE (why do you think this is happening.
Example- If the IV increases, then the DV will decrease because….
6. Write your Methods (20pts)
Procedures are a list of materials used in the experiment and the steps in performing the experimental part. Procedures are the recipe you follow in order to perform the experiment. Write these in order, in paragraph form, and using your own words. Do not simply copy and paste from the student lab guide. Avoid first person language!
7. Create your Data Table (5pts)
Data is recorded during the procedures. You need to create your data collection table for your experiment. Below is an example Data collection table. Create your own collection table using labels with the names of your variables and the correct units you are measuring. Do not collect data yet! You are just setting up the table so you are ready to collect data when it is time to run your experiment. Wait until you get feedback from this assignment to begin any data collection
{Insert name of Independent Variable} (insert units)
{Insert name of Dependent Variable} (insert units)
Average { Insert name of Dependent Variable }(insert units)
Trial 1 *
Trial 2 *
Trial 3*
Control
{Insert Treatment 1 Name}
{Insert Treatment 2 Name}
{Insert Treatment 3 Name}
*Repeated Trials——Why repeat the experiment more than once?
Mistakes happen no matter how careful you are so if you repeat the experiment you will get more reliable data. The more repeated trials the more likely you will reduce the effect of chance errors and the more reliable your data becomes and the more confidence you can place in your data. Generally a minimum of 3 trials is acceptable for experiments with more being better.
Here are some helpful videos that walk you through the setup steps involved in conducting the experiment:
AP Biology Investigation
Vernier Video (uses old gas pressure sensor)
Read through the attached documents to understand how you will customize the experiment and make it your own.