In this experiment, you will be learning about hypothesis, variables, data interpretation, and how to put the scientific method into action. Make sure to carefully read the pre-lab and lab before you begin. It will help to read the lab questions as you wait for your experiment to finish up, and think about how the variables are interacting in your experiment.
Understanding how to make a hypothesis and how variables interact in scientific experiments is crucial to getting consistent results, and learning from those results.
A hypothesis is a statement that makes a prediction about an outcome; it is an educated guess in regards to an experiment. This is a good example of a hypothesis: If I keep my curtains closed during the day, then my room will stay cooler. An easy way to help make a hypothesis is to use an “If….then” structure. If x happens, then it affects y. For instance, the example hypothesis is predicting that keeping the curtains closed during the day will keep the sun from heating up the bedroom. Is that a true statement? To test the statement, one would need to design and conduct an experiment to see if the hypothesis is supported or disproved.
Hypotheses aren’t just used for science, either- they are applicable in various facets of life because they help to solve problems by problem diagnosis and elimination of solutions that haven’t worked. For example, if your television remote stopped working, you might make a hypothesis to try to find out what’s wrong with it. If you think the batteries are the culprit, then your hypothesis could be written: “If I change the batteries, then the remote will control the tv again.” You change the batteries in the remote and then sit down to test it. If the remote works with the tv, then you solved the problem, and your hypothesis was supported. If the remote still does not work, then your hypothesis was disproved, and you need to design another experiment; if the next test does not yield the results you are looking for, then you design another test, and so on and so forth. This cycle continues until you obtain your desired result or discontinue the experiment; the same cycle is followed daily by scientists conducting experiments. By design, hypotheses need to be testable, which is why scientists like to use the "If....then" format to help phrase the hypothesis correctly.
In the tv remote scenario, you were testing different things that you thought might be causing the remote to not work; the things that you were changing are called independent variables. Independent variables are changed by you---the experimenter. In any experiment, you should only be changing one variable at a time; this allows you to clearly test the outcome of changing that one variable. For example, let’s say you changed the batteries in the remote and moved items that you thought might be blocking the remote’s signal. You then test the remote, and it works! Were the batteries the problem? Or was the signal being blocked? You have no way to know which variable solved the problem, since you tried to test two at the same time. This is why it is very important to only change one variable when designing an experiment.
The other two types of variables in an experiment are dependent variables and controlled variables. Dependent variables are “dependent” on the independent variable, because they are caused by the changing of the independent variable. In our ‘if x happens, then it affects y’ statement, y would be the dependent variable. X would be the independent variable, and the one being tested, and the one that scientists are manipulating. Y is the one that is being measured. In our tv remote example, being able to control the tv with the remote is dependent on the independent variable (fixing the problem). Scientists focus on the dependent variables to measure the results of the experiment. Controlled variables are the variables that stay exactly the same during the experiment. Since scientists only want to manipulate one variable at a time, they try to keep everything else the exact same across the experiment so the results can be as accurate as possible. An example of a controlled variable for our remote example would be staying the same distance from the television while testing the remote, or pressing the same buttons. If these variables are changed, it could affect the results of the experiment.
Pre-lab Questions:
1. Define the terms hypothesis, independent variable, dependent variable, and controlled variable in your own words.
2. For the following experiment (with Susan), write a possible hypothesis, and then identify the independent variable, dependent variable, and controlled variables.
Susan wants to find the fastest route to bike to youth group. She can take arterials, residential roads, or bike paths on her way to youth group.
3. We discussed the importance of having only one independent variable, but trying to test more than one independent variable is an error many people make. In the following experiment (with Dan), identify the errors that the experimenter made and summarize a valid way to test his research question.
What cooking spray best keeps food from sticking to a pan? In the morning, Dan uses grapeseed oil to cook eggs for breakfast; for lunch, he uses vegetable oil spray to coat a muffin try and cooks cornbread to eat with his chili; and for dinner, he uses olive oil to pan cook a hamburger patty.
4. What might a good process for forming a hypothesis look like? What factors should you consider when making a hypothesis?
In this experiment, you will create three different types of paper airplanes. First, read the background information on hypothesis and variables, and fill out the pre-lab questions. Next, you will need to develop a hypothesis. Your airplanes can be created using different sized paper, using different types of paper, or adding different amounts of paper clips to the wings. Predict which one will fly the farthest.
Write your prediction as a hypothesis using the “If...then…” format. If you have any questions regarding this format, please use the “Ask for Help” button to ask for a teacher’s help or look for resources on the course LiveBinder site. Once you have made your prediction, follow the steps below to complete the experiment.
Your final step will be to evaluate your results and write a formal lab report. Formal lab reports contain hypothesis, procedure, data, questions, and conclusion sections. An example is available for reference in the LiveBinder for this course, and there is an outline for reference at the end of this assignment page.
Paper
Meter Stick or Metric Ruler
Paper clips
Reminder: You only need to choose 1 independent variable. Please follow the instructions for one of the options.
Directions for using different types of paper:
Gather three different types of paper (printer paper, construction paper, card stock, tissue paper, etc.)
Using the picture, build 3 paper airplanes using different types of paper.
Use a piece of tape to mark a starting point on the floor.
From the starting point, throw airplane 1 in a forward direction.
Once it has landed, use a meter stick to measure how far it has traveled. Record the distance into the data table.
Repeat steps 5-6 two more times for a total of 3 trials.
Repeat steps 5-7 for the other two airplanes.
Directions for adding paper clips:
Gather three sheets of paper.
Build 3 paper airplanes using the picture as a guide
For your first airplane, do not add any paperclips. For your second airplane, add one paper clip to each wing. For the third airplane, add two paper clips to each wing.
Use a piece of tape to mark a starting point on the floor.
From the starting point, throw airplane 1 in a forward direction.
Once it has landed, use a meter stick to measure how far it has traveled. Record the distance into the data table.
Repeat steps 5-6 two more times for a total of 3 trials.
Repeat steps 5-7 for the other two airplanes.
Directions for different sized airplanes:
Gather three sheets of paper.
Build 1 paper airplane using a whole sheet of paper.
Build two other paper airplanes using a different pattern or using the same pattern on a smaller piece of paper.
From the starting point, throw airplane 1 in a forward direction.
Once it has landed, use a meter stick to measure how far it has traveled. Record the distance into the data table.
Repeat steps 5-6 two more times for a total of 3 trials.
Repeat steps 5-7 for the other two airplanes.
Data:
Answer the questions provided below, in detail:
What parts of the scientific method were illustrated in this experiment? List each.
What was the dependent variable?
What were the constants in your experiment?
Which independent variable did you choose? Why did you choose that independent variable?
Which airplane flew the farthest? Why do you believe that airplane flew the farthest compared to the other two?
Evaluate your hypothesis by stating whether it was supported or disproved; use your data to support your evaluation. In this section, you should also note any unexpected results, explain the concepts illustrated, describe what you learned, and list any changes you would make to the lab (materials, procedure, etc.). Your conclusion should be 5 or more sentences in length.
Heading and unique title
Pre-lab, hypothesis, procedure, data, analysis, post-lab, and conclusion section headings
Each section is thorough and complete
Lab report typed into a word processor (such as Microsoft Word) and saved
Typed lab document uploaded to Ignitia and submitted
Steps of Project Overview:
Project Overview
Additional Resources:
Downloadable copy of lab report
LiveBinder
Lab Report Rubric:
A sample of the lab report format is given below.
Lab Report Format:
Your Name
Teacher Name
Course Name
Date Report Completed
Prelab Questions
Answer all four Pre-lab Questions below.
Hypothesis
Write your prediction of the results of the experiment. Remember to use the “If...then…” format.
Procedure
Summarize the steps that you took to complete this experiment; write your summary in third person present tense form. Make sure to include enough detail for someone else to repeat the experiment using only what you write in the procedure section.
Data
Describe the results of your experiment in detail, but do not explain the data. Include distances into the data table below.
Post-Lab Questions:
Answer the questions provided below, in detail:
What parts of the scientific method were illustrated in this experiment? List each.
What was the dependent variable?
What were the constants in your experiment?
Which independent variable did you choose? Why did you choose that independent variable?
Which airplane flew the farthest? Why do you believe that airplane flew the farthest compared to the other two?
Conclusion:
Evaluate your hypothesis by stating whether it was supported or disproved; use your data to support your evaluation. In this section, you should also note any unexpected results, explain the concepts illustrated, describe what you learned, and list any changes you would make to the lab (materials, procedure, etc.). Your conclusion should be 5 or more sentences in length.
In this experiment, the parts of the scientific method that were illustrated include formulating a hypothesis, conducting the experiment, collecting and analyzing data, and drawing a conclusion.
The dependent variable in this experiment is the distance that each paper airplane travels.
The constants in the experiment are the starting point, the force used to throw the airplane, and the measuring tool (meter stick).
I chose the independent variable of using different types of paper for the airplanes. I chose this variable because I wanted to test how the different types of paper would affect the flight distance of the airplanes.
Based on my data, the airplane made from card stock flew the farthest. I believe this is because card stock is thicker and more rigid than the other types of paper, which allowed it to stay in the air longer and travel a greater distance.
In conclusion, my hypothesis was supported by the data. The airplane made from card stock flew the farthest, followed by the one made from construction paper, and then the one made from tissue paper. The experiment showed that the type of paper used does affect the flight distance of a paper airplane. I also learned that the weight and rigidity of the paper play a role in how far the airplane can travel. If I were to repeat this experiment, I would consider using even more types of paper to see if there are any other factors that could affect the flight distance.