The Steps of the Scientific Method 1. Identify a Problem/Ask a Question 2. Conduct Background Research 3. Form a Hypothesis 4. Design an Experiment 5. Collect & Analyze Data 6. Draw a Conclusion 7. Communicate your Results
1. Identify a Problem/Ask a Question The Scientific Method begins by choosing a topic that interests you and identifying a problem related to that topic. Then you should ask a question about something you can measure. A scientific research question usually starts with: How, What, Who, Which, Why, or Where. You have asked a good research question if you can design an experiment to answer it. An experiment requires that you change only one factor (variable) and keep all other conditions constant. If you can not design such an experiment, you should revise your question with the help of your mentor and/or chapter coordinator. Ideally, your question will involve factors or traits that you can measure numerically (like distance or time), or observe objectively (like colors). Simple Example Problem: I’m interested in craft projects. I’ve noticed that sometimes glue is easier to spread than other times. Question: Will glue flow faster when it is warmer? Environmental Examples Problem: I’m interested in water quality. I’ve noticed that the river that flows through my community is very murky and looks dirty. Question: What sections of the river are brown and what sections are clear? or What causes certain sections of the river to be brown? Problem: It’s very noisy outside my school and it distracts me from doing my school work. Question: Do students in a quiet school environment earn better grades than students in a noisy school environment?
Your EnvironMentors Project You will complete Step 1 of the Scientific Method in Section 4: Project Planning. You will use brainstorming to identify an environmental topic that interests you, and then make a list of what you know and don’t know about the topic in order to identify a problem, and then ask a question. The Project Topic Form assignment will help you organize your thoughts and ideas.
2. Conduct Background Research The next step in the Scientific Method is finding out what is already known about your problem by conducting background research. You can use the library, the internet and talk to experts. Your background research will help you make an educated guess about the answer to your question, and will also save you from starting from scratch in putting together a plan for answering your question. When doing your background research you should: •
Identify keywords in your question and use question words (why, how, who, what, when, where) to develop research questions such as: When does a plant grow the most, during the day or night? and Why are moths attracted to light?
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Look for information about similar research projects and find out what was learned in those experiments.
Simple Example Research Questions: What affects the “stickiness” of glue? My mentor mentioned viscosity, what does that term mean? What other experiments have been done on glue? Environmental Examples Research Questions: What affects the clarity of the water in the river that flows through my community? My mentor mentioned turbidity, what does that term mean? How do you measure turbidity? What other experiments have been done on river turbidity? Research Questions: What is noise pollution? Does the amount of traffic outside of my school increase noise pollution? What other experiments have been done related to noise pollution? What other experiments have been done on the factors that affect students’ learning? Your EnvironMentors Project You will complete Step 2 of the Scientific Method in Section 5: Background Research. You will learn how to use the library and internet for research and how to create an annotated bibliography. With the help of your mentor, you will also identify a local expert on your topic and interview them. Using what you’ve learned from your library and internet research, as well as your expert interview, you will complete the Background Research Paper assignment.
3. Form a Hypothesis After researching your topic area, you’ll be more knowledgeable about the problem you identified in Step 1. Based on what you now know about your topic, you’ll be able to form a hypothesis. A hypothesis is an educated guess about the answer to your question. When wording your hypothesis,
be careful to word it in a way that can be tested by your experiment. Do this by identifying both the variable you will change during your experiment (independent variable) and the variable whose changes you will observe (dependent variable). You can state your hypothesis in the following form: If the independent variable is changed in a certain way, the dependent variable will change is a predictable manner. Simple Example Background knowledge: Liquids expand when they get warmer and flow more easily. Hypothesis: When the temperature of the glue is raised, it will flow faster. Environmental Examples Background knowledge: Factors such as shoreline erosion and runoff can increase the turbidity of river water. Turbidity is the amount of total suspended solids in water. The higher the turbidity the harder it is to see to the bottom of the river. Hypothesis: If I measure the turbidity of the river water at different sites, it will be higher in areas where there has been recent significant shoreline erosion. Background knowledge: Other studies have shown that students usually learn better in a quiet environment. Hypothesis: The average test scores of students at a school with a lot of noise pollution will be lower than the average test scores of students at a school in a quiet neighborhood. Your EnvironMentors Project You will complete Step 3 of the Scientific Method in Section 6: Forming a Hypothesis. After assessing what you learned about your topic from your background research, your mentor and/or your chapter coordinator will help you develop a hypothesis. You will complete the Hypothesis Form assignment.
4. Design an Experiment Your experiment will test your hypothesis and it is important that your experiment is a fair test. In order to conduct a fair test, you should be sure that you change only one factor, or variable, at a time, while keeping all other conditions the same. You should repeat your experiment multiple times to be sure that the results aren’t just an accident. You should write your procedure like a step-by-step recipe for your experiment. Your procedure should be detailed enough that someone else could repeat your experiment just by reading it. Your materials list should include all the supplies and equipment you will need to complete your experiment. By making your list and gathering your materials ahead of time, you can be sure that you will have everything on hand when you need it. It is a good idea to make your materials list well in advance because some items may take time to obtain.
Simple Example Procedure: 1) Draw three circles along one edge of a piece of cardboard. Label one circle hot, one room temperature, one cold. 2) Put one bottle of glue in ice water for five minutes and one bottle of glue in hot water for five minutes. Leave one bottle of glue at room temperature. 3) Place five drops of glue from each bottle in the appropriately labeled circle on the cardboard. 4) Tilt the cardboard by placing
the upper end on a book so the glue flows down the cardboard. 5) After one minute, measure the distance each drop of glue flowed. 6) Repeat the experiment 2 more times. Materials: 3 bottles of the same kind of glue, 1 container of ice water, 1 container of hot water, 3 pieces of cardboard, 1 ruler, 1 thick book. Independent variable: the temperature of the glue. Dependent variable: the distance the glue flows on the cardboard. Controlled variables: the kind of glue, the amount of glue, the height of the cardboard, the respective temperatures of the ice water, hot water, and room. Experimental group: the trials with hot and cold glue. Control group: the room temperature glue. Environmental Examples Procedure: 1) Locate a portion of the river that has a relatively the same width for several meters. 2) Pick and label with a flag or marker three or more sample sites, 10 meters apart along the river bed. 3) At each site, collect a sample of water in a clear bucket or bottle, making sure not to stir up river sediment on the shore as you collect the sample. 4) Thoroughly mix the water in the container to ensure that settled sediment in the container rises off the bottom. 5) Gradually pour the sample into the turbidity tube, while looking straight down at the bottom of the tube. As you are doing this, make sure to hold the tube out of direct sunlight as it may alter your measurements. 6) Stop pouring the sample into the tube when the design (the black and white checkers) on the bottom of the tube is not visible. To check your results, rotate the tube to make sure you still can’t see the bottom. 7) Record the measurement on the side of the tube (in Nephelometric Turbidity Units, NTU’s). If the measurement is between two NTU’s record the lowest value. 9) Repeat at each of the three or more sites three times to ensure an accurate reading. Be sure to rinse out the turbidity tube with tap water each time to decrease the possibility of error and contamination. 10) To determine the link between turbidity and soil erosion, take the set of measurements before a rainstorm and after, as rain causes sediment to be pulled from the ground into bodies of water, therefore increasing the amount of sediment in the river and hence the river’s turbity. 11) In total, there should be at least nine data sets (three for each location) for both before and after a storm. This experiment will tell you how erosion changes turbidity at three different points along a river. Materials: Turbidity tube with NTU measurements and a black and white disk at the bottom, clear bucket, pencil and paper for recording data, tap water, a meteorological report to predict an upcoming rainstorm, meter stick to measure distance between points along the river, flags to designate locations so experimenters will be able to return to the same location before and after the storm. Independent variable: Soil Erosion Dependent variable: Turbidity Controlled variables: location, turbidity tube. Experimental group: Trials at each distance after the storm Control group: Trials at each distance before the storm. Procedure: 1) Obtain sound level meter, to determine sound levels in classrooms in decibels (db). 2) Choose a quiet location that you determine to be your control, and calibrate the sound level meter to decibel level zero. You must recalibrate your sound level meter to zero at each different location that you take a reading. 3) Gather average test scores for a specific course and grade level for six local schools (e.g. average test scores for 9th grade mathematics). 4) At each of the six schools, locate all the classrooms for your chosen grade and course (e.g. rooms 202, 204, 206, and 214 are the classrooms where 9th grade mathematics is taught at X Senior High School). 5) At a pre-determined time (must be the same for each school), find the center of each classroom and take the decibel reading. 6) This experiment will show you the amount of noise in each classroom, which can then be compared to test scores. Materials: Average test scores for each of the six schools studied, pen and paper for recording data, sound level meter
Independent variable: classroom location by school Dependent variable: noise pollution in decibels (db) Controlled variables: location within the classroom, sound level meter, test scores Experimental group: the amount of noise pollution in each room Control group: the zero decibel reading at a pre-determined quiet area. Your EnvironMentors Project You will complete Step 4 of the Scientific Method in Section 7: Designing an Experiment. You will learn more about designing an experiment, identifying independent and dependent variables, as well as a control data set during the Experimental Methods Workshop. You will also complete the Experimental Methods & Materials List assignment.
5. Collect & Analyze Data When conducting your experiment, you should be sure to record all your data in an organized manner. You should follow your procedure exactly, and record any changes that are necessary. Be careful to only change your independent variable and keep all other variables constant. It is also very important to be safe while doing your experiment. For example, if your experiment requires you to go out on a boat to collect water samples, make sure you are wearing a life jacket. If you need to do some chemistry to analyze your water samples, be sure to wear the necessary protective equipment. If you’re not sure what safety equipment you need, consult your mentor and/or chapter coordinator. After collecting your raw data, you will need to perform some calculations in order to analyze your data and form a conclusion. This often involves calculating a mean, or average, of all data from all your experimental trials. Graphs are usually the best way to display your data so that it is easy for others to understand. Most scientists will use the x-axis for the independent variable and the y-axis for the dependent variable. Bar charts and pie charts can also be useful. Examples calculations and graphs and charts are provided in Section 8. Simple Example Raw data: Distance the hot, cold, and room temperature glue traveled on the cardboard for five experimental trials. Analysis: Calculate the mean distance traveled by each of the three glue temperatures. Create a graph or table that displays your data in a way that is easy to understand. Write a description of the data in words (The hot glue traveled the farthest distance, and the cold glue traveled the shortest distance). Environmental Examples Raw data: Three data sets, with three data points at each location down the river before the storm as well as after the storm. Analysis: Calculate the average difference between turbidity at each location before and after the storm. Determine the statistical significance of change in turbidity versus change in soil erosion. Create a graph or table that displays your data in a way that is easy to understand visually. Write a description of the data in words. Raw data: Data points for the decibel reading from each of the chosen classrooms within each of the six schools.
Analysis: Calculate the average decibel level for the classrooms in each school. If you choose six schools, you will then have six average decibel readings. Compare average test scores to noise pollution and calculate the statistical significance. Create a graph or table that displays your data in a way that is clear and easy to understand. Write a description of the data in words to prove or disprove your hypothesis. Your EnvironMentors Project You will complete Step 5 of the Scientific Method in Section 8: Data Collection & Analysis. During the Experimental Methods Workshop you will learn how to keep a good record of your experiment, how to collect data in an organized fashion, and how to create graphs using Microsoft Excel. You will complete both the Raw Experimental Data and Data Analysis assignments.
6. Draw a Conclusion Once you have analyzed your data, you can determine whether they support or disprove your hypothesis. Scientists often find that their hypothesis was false, but this does not mean that their experiment was incorrect. Scientists often learn the most when their data show something that was unexpected. Even if your data support your hypothesis, it is still a good idea to test it again in a different way. A good conclusion will suggest future experiments that will build on what you have learned, and help you and other scientists learn more about your topic area. Simple Example The data indicate that the warmer glue traveled the farthest. This supports the hypothesis that when the temperature of glue is raised, it will flow faster. It would be useful to repeat this experiment with different types of glue, or with more temperatures. Environmental Example Turbidity example – The data indicated that turbidity levels were increased at the three designated locations after a rainstorm. This supports our hypothesis that soil erosion increases turbidity of the water. It would be useful to repeat this experiment in other rivers, after different storms, and with more trials to decrease error. Noise pollution example – The data indicated that there was a correlation between higher noise pollution and lower test scores. This supports our hypothesis that average test scores will be higher in areas of lower noise pollution. It would be useful to repeat this experiment in other school departments as well as over a larger variety of schools.
Your EnvironMentors Project You will complete Step 6 of the Scientific Method in Section 9: Drawing a Conclusion. With the assistance of your mentor and/or chapter coordinator, you will determine what your data are telling you and whether or not they support your hypothesis.
7. Communicate Your Results Perhaps the most important part of the Scientific Method is to communicate your results to other scientists and to the public. Remember that the information you gathered during your background research was available because other scientists completed this critical step of the Scientific Method. When writing a report, you should use clear, objective language and avoid the use of the First Person (I think‌ or I measured‌). You should also use the active voice whenever possible, as it is more concise than the passive voice. When presenting your research orally, it is often helpful to have visual aids that will help your audience understand your research project. You can show pictures of your experimental site, as well as graphs and charts. Your visual aids should enhance your presentation, but not be your entire presentation. If you use slides, avoid merely reading your slides to the audience, which can be boring. Try to be animated and make your audience as excited about your project as you are, while still presenting yourself in a professional manner. Your EnvironMentors Project You will complete Step 7 of the Scientific Method in Section 10: Communicating Your Results. You will learn how to write like a scientist and how to present your results orally to both your peers and to the general public. You will complete the Final Research Paper, Project Display Board, and Elementary School Visit Lesson Plan assignments.
Some content reproduced from: Science Buddies (http://www.sciencebuddies.org/mentoring/project_scientific_method.shtml) Energy Fair Scientific Method, The NEED Project (http://www.eia.doe.gov/kids/classactivities/EnergyFair2002.pdf)
Test Your Knowledge 1. The Scientific Method was developed to help scientists organize the process of solving problems. a. True
b. False 2. Which of the following is not a step in the Scientific Method?
a. b. c. d.
Form a hypothesis Communicate your results Plagiarize Draw a conclusion
3. A hypothesis is: a. A random thought b. An answer c. An educated guess d. An experiment 4. Which of the following words are not associated with the Scientific Method? a. Disorganized b. Organized c. Data d. Control 5. What to you do to test a hypothesis? a. Guess b. Create a spreadsheet with data c. Write a scientific paper d. Design an experiment 6. An independent variable is a factor that changes because of procedures conducted on the dependent variable. a. True b. False 7. Experiments often test multiple variables at once. a. True b. False
8. Experiments are usually conducted one time and by one scientist to speed up the scientific process. a. True b. False Fill in the blank(s): 9. Your hypothesis is a(n) _______________ based on information gathered from doing __________ research. 10. The experimental method must list your _______________ and _______________. 11. There should be only one ______________, or characteristic of your experiment, that will change. 12. _______________ is shown in the form of tables and graphs. 13. Your _______________ must state whether your data supported or disproved your _______________. 14. Put a number next to each step of the Scientific Method to indicate the order in which you should complete it: ___ Draw a conclusion ___ Identify a problem ___ Collect data ___ Form a hypothesis ___ Analyze your data ___ Do background research 1. a; 2. c; 3. c; 4. a; 5. d; 6. b; 7. b; 8. b; 9. educated guess, background; 10. procedure, materials; 11. variable; 12. data; 13. conclusion, hypothesis; 14. 6,1,4,3,5,2
Adapted from: Biology4Kids (http://www.biology4kids.com/extras/quiz_studyscimeth/index.html) A Science Fair Handbook by Sandy Lautz (http://192.107.108.56/portfolios/l/lautz_s/science%20Fair%20handbook/SFquiz.html