~Experimental Design~
~Science Fair ~
Name: ______
Homeroom:______
Cosmic Wonders 2011 Science Fair
Table of Contents & Due Dates
q p. 2 – Anticipation Guide
q p. 3 – Picking a Good Topic
q pp. 4-6 – Posing a Good “BIG Question”
q pp. 7-8 – Answering Your “BIG Question”
q pp. 9-10 – Making and Wording a Good, Clear Hypothesis
q pp. 11-13 – Identifying Variables
q p. 14 – Designing an Experiment
q pp. 15-16 – Identifying Constants
q pp. 17-20 - Review of Variable, Constants, Controls
q p. 21 – Materials
q p. 22 - Procedure
q p. 23 – Collecting & Interpreting Data; Drawing Conclusions
q p. 24 – Displaying Your Project
q p. 25 – Checklist – SEE DUE DATES BELOW!!!
q p. 26 – Safety Checklist
q p. 27 – Glossary of terms
q p. 28 – Journal Example
q p. 29 – Presentation Expectations
q p. 30 - Variables/Groups/Controls for YOUR experiment
q p. 31 – Research Check
q pp. 32-33 – Proposal – DUE BY THURS. 4/7
- no duplicate experiments in one class; first come, first serve
DUE DATES
q Proposal due no later than Thurs. 4/7
q TYPED Materials & Procedure due Mon. 4/11
q Variables/Groups/Controls List (p. 7B) due Wed. 4/13
q Research Check due Fri. 4/15
q Data Check #1 due Wed. 4/27
q Data Check #2 due Thurs. 5/5
q Rough Draft of ALL Final Items (TYPED) due Mon. 5/16
q Presentations – Week of May 23rd
Anticipation Guide
Read each statement. In the “My Answer” column right an A if you agree or a D if you disagree with the statement.
Statement / My Answer / Final Answer1. When scientists are posed with a question they want answered, they follow a specific procedure called the scientific method.
2. When forming a hypothesis to a question make sure you guess correctly.
3. During an experiment, a variable is a part of the experiment that stays the same.
4. Throughout an experiment, be sure to collect data accurately.
5. A conclusion is a summary of what you have learned and should match your hypothesis.
Terrific Topic!
You probably have a good idea of what topic you would like to choose for your science fair project. It’s important that your topic be one that you are interested in and can experiment with yourself.
A good topic is one that you can perform experiments on. It is more than just researching a topic, writing a report, drawing pictures and building a model. The topic must not be too general. Here are examples of good and bad topics.
Good Topic
“Which brand of popcorn pops the most kernels?” – This is a good topic because you can find the answer by doing experiments.
Poor Topic
“Bridges” – This topic is too general, or big. You could not do a good job of studying a topic that is this big. Choose a smaller, or more specific topic, such as, “Which bridge designs can support the most weight?”
Decide which of the science fair projects listed below are “Thumbs Up” (good topics) and which ones are “Thumbs Down” (poor topics). Put a ümark in the appropriate column.
Poor / Topic / Good“The effect of fertilizer on plants”
“How much of an apple is water?”
“Which gets warmer – sand or dirt?”
“Clouds”
“Heat affects the bounce of a basketball.”
“What foods do meal worms prefer?”
“Erupting Volcanoes”
“Ants”
Write your own example of a good topic: ______
Posing Questions
Scientific inquiry often begins with a problem or question about an observation. Of course, questions don’t just come to you from nowhere. Instead, questions come from experiences that you have had from observations and inferences that you make. Curiosity plays a large role as well. Think of a time that you observed something unusual or unexpected. Chances are good that your curiosity sparked a number of questions.
Some questions cannot be investigated by scientific inquiry. Think about the differences between the two questions below.
X Why has my CD player stopped working?
X What kind of music should I listen to on my CD player?
The first question is a scientific question because it can be answered by making observations and gathering evidence. For example, you could change the batteries in a CD player and observe whether it begins to work. In contrast, the second question has to do with personal opinions or values. Scientific inquiry cannot answer questions about personal tastes or judgments.
That’s a Good Question
What do you want to learn from a science project? State this in a clearly written question, called the Big Question. A good question can be answered by measuring something.
Highlight the question that is more specific and can be answered by measuring.
Circle the key word(s) that indicate that the question is measurable.
1. a. Which paper towel is the best?
b. Which paper towel absorbs the most water?
2. a. How much of an apple is water?
b. Does an apple contain water?
3. a. How does playing video games affect your heart rate?
b. Does playing video games affect your heart?
4. a. How does fertilizer affect the growth of plants?
b. How do bean plants grow?
5. a. What is the best brand of raisin bran cereal?
b. Which brand of raisin bran cereal has the most raisins?
6. a. With which brand of battery do toys run the longest?
b. What is the best brand of battery?
7. a. What is the best brand of golf ball?
b. Which brand of golf ball flies the farthest?
8. a. Is it better to take a shower or a bath?
b. Do showers use less water than baths?
9. a. Will aspirin make cut flowers last longer?
b. Is aspirin good for cut flowers?
10. a. From which direction does the wind blow most frequently?
b. Does the wind blow?
Rewrite the following questions more clearly.
11. What is the best kind of soap?
______
12. Is an orange juicy?
______
Posing Questions
Examine the statements below. For each item, write yes if the topic can be investigated scientifically. Write no if it cannot be investigated scientifically. Then for each item to which you answered yes, rewrite the topic in the form of a scientific question.
1. Some people work better in the morning, and other people work better in the afternoon.
______
2. Taking something that belongs to another person is wrong.
______
3. Snakes travel in pairs.
______
4. Animals behave in strange ways before an earthquake.
______
5. People who don’t recycle should have to pay fines.
______
6. Basketball is a better sport than soccer.
______
7. You will remember best whatever you read just before you fall asleep.
______
8. Maria’s kind of bike is faster than Rob’s kind of bike.
______
9. Each year when the weather gets cold, birds fly to warmer regions.
______
10. Trucks use more gasoline than cars.
______
What’s the Problem?
Tony has chosen “water conservation” as his topic for his science project, but the topic is too general. The best way to narrow his broad topic is to phrase his topic into a question that asks exactly what he is trying to find out. This question is referred to as the BIG Question. Tony’s BIG Question is: “Does taking a shower use less water than taking a bath in a tub?”
After Tony has written his BIG Question, he takes a careful guess at what he will find out. This careful guess is called a hypothesis. Tony’s hypothesis is: “Showers use less water than baths.”
Practice narrowing down broad topics by writing a BIG Question and a hypothesis for each topic. Some boxes have already been completed for you.
Topic / BIG Question / Hypothesis1. Water Conservation / Does taking a shower use less water than taking a bath in a tub?
2. Bouncing Balls / When more air is put in a basketball, it will bounce higher.
3. Plants / Warm temperatures help seeds sprout more quickly.
4. Hearts / Playing video games increases your heart rate.
5. Consumer Science / Which paper towel absorbs the most water?
6. Fruit and water / Apples are more than 60% water.
Your Prediction
“Will the weather be sunny and warm tomorrow, or will it rain?” Scientists, including meteorologists, often ask questions and then make predictions. In a scientific investigation a prediction is called a hypothesis. A hypothesis is a careful guess.
A clearly written hypothesis (1) answers the question, (2) is brief and to the point and (3) uses the same
“vocabulary” as the question. Read the sample question and hypothesis. Notice the underlined words.
Question: Does the depth of a planted bulb affect its growth?
Hypothesis: If bulbs are planted at different depths, then the bulbs that are planted deeper will not grow as tall.
Pretend you are a scientist and write a hypothesis for each of these questions. It does not matter if the hypothesis is correct.
Question: Will frozen seeds sprout?
Hypothesis: ______
Question: Can a mouse be taught to run in a maze?
Hypothesis: ______
Question: Do all people have the same body temperature?
Hypothesis: ______
Question: How much can a caterpillar eat in one day?
Hypothesis: ______
Question: How long does it take a meal worm to travel 5 centimeters?
Hypothesis: ______
Question: Who has the fastest heart rate – big people or small people?
Hypothesis: ______
Developing a Hypothesis
How could you explain your observation of noisy crickets on a summer night? “Perhaps crickets chirp more when the temperature is higher,” you think. In trying to answer the question, you are developing a hypothesis. A hypothesis (plural: hypotheses) is a possible explanation for a set of observations or answer to a scientific question. In this case, your hypothesis would be that cricket chirping increases at higher temperatures.
It is important to realize that a hypothesis is NOT a fact. Instead, it is only one possible way to explain a group of observations. In this case of the crickets, perhaps they only sounded louder that night because you had left more windows open than you usually do. Or, maybe there were more crickets around that night.
In science, a hypothesis must be testable. This means that researchers must be able to carry out investigations and gather evidence that will either support or disprove the hypothesis. Many trials will be needed before a hypothesis can be accepted as true.
Forming a Hypothesis
While an inference is a tentative explanation based on observations and prior knowledge, a hypothesis is a tentative explanation for an observation or scientific problem written in a special way that leads to further investigation. You can write a hypothesis in the form of an “If…, then…” statement. Keep in mind these important points about a hypothesis.
Ø The results of an experiment cannot prove a hypothesis is correct. Rather, the results either support or do not support the hypothesis.
Ø You can gain valuable information even when your results do not support your hypothesis.
Ø In science, a hypothesis is supported only after many scientists have conducted many experiments and produced consistent results.
Use the “If…, then…” format to write hypotheses about the following scientific problems. The first one is done for you.
1. Problem: How does fertilizer help tomato plants produce more tomatoes?
Hypothesis: If fertilizer is added to plants, then the plants will produce more tomatoes.
2. Problem: Which produces higher grades on science tests, studying with music on, or studying with quiet conditions?
Hypothesis: ______
______
3. Problem: What is the relationship between the number of ducks living on ponds and the amount of bacteria in the pond water?
Hypothesis: ______
______
4. Problem: How do vitamin C supplements help prevent colds?
Hypothesis: ______
______
Identifying Variables
Variables are any of the factors that could change in a scientific investigation. A controlled scientific investigation is designed so that only one factor is changed or manipulated. However, one or more factors may be measured during an experiment. All other factors remain constant throughout the study. Suppose that you wanted to conduct an experiment to see how the amount of water a plant receives affects its growth. Your hypothesis for this experiment might be “If I give different plants different amounts of water, then the plants will grow at different rates, because the amount of water a plant receives affects its growth rate.
Ø The independent variable is the factor that you wish to test and that you manipulate or change so that you identify its effects. When you use the “If…, then…, because…” to write your hypothesis, the independent variable is found after the word if. In the example above, you are intentionally changing the amount of water. Therefore, the amount of water given to the plants is the independent variable.
Ø The dependent variable is the factor that you measure to gather results. It is expressed in your hypothesis after the word then. In the example above, you are measuring plant growth. Therefore, plant growth is the dependent variable.