eq: what is the scientific method. identify problem or question observation/research formulate a...

EQ: What is the Scientific Method

Identify problem or questionObservation/Research

Formulate a HypothesisExperiment

Collect and Analyze ResultsConclusion

Communicate the Results

Steps of the Scientific MethodRevamped to a

Circuitous Approach

http://mjksciteachingideas.com/pdf/STITutorial6.pdf/

PURPOSEIn this lesson, you will learn how to use the scientific method to create and conduct

experiments.

OBJECTIVES

1. How to write a problem or question 2. How to construct a hypothesis 3. How to design an experiment 4. How to conduct an experiment 5. How to collect data 6. How to graph data 7. How to draw conclusions

Objective 1Choosing a Problem/Question Develop a question or problem that can be solved through experimentation.

Problem/QuestionYour question must include both an independent (manipulated) and a dependent variable (responding).

An independent variable (or IV for short) is something that you intentionally change in your experiment.

A dependent variable (or DV for short) is something that changes as a result of what you intentionally changed.

Problem/QuestionExamples of good questions:

How does the amount of sunlight affect the growth of bread mold?How does color influence people's food choices?How is brand name related to the absorbency of paper towels?How does age affect a person's reaction time?How do different diet supplements affect a cat's coat?How does the size of a wheel affect the speed of a hotwheels car?

Problem/QuestionObjective 1 Quiz

How are rainbows formed? No Manipulated or Responding VariableDifficult to get materials Unsafe question Good question

Problem/Question

Objective 1 Quiz

How are rainbows formed?No Manipulated or Responding Variable

Problem/QuestionObjective 1 Quiz

How does the type of liquid a plant receives affect its growth? No Manipulated or Responding Variable Difficult to get materials Good question Not a safe question

Problem/Question

Objective 1 Quiz

How does the type of liquid a plant receives affect its growth?Good question

Observation/ResearchMake observations and research your topic of interest.

A hypothesis is an educated guess about the question

To construct a hypothesis, all you really have to do is ask yourself what you think the outcome of the experiment will be. Use your head and research that you may have already conducted to help you guess what the answer will be.

Formulate a Hypothesis

Begin a hypothesis with "I think that..."

Because the purpose of a hypothesis is to make a prediction or guess about the answer to the question, you should always start your hypothesis out with "I think that..."

Formulate a HypothesisUse an "If...then..." statement

An "If...then..." statement is one that shows a cause and an effect relationship.

Example:

“I think that if a plant is given acidic liquids, then the plant's growth will decrease."

In this hypothesis, there is a cause (acidic liquid) that produces an effect (decrease in plant growth).”

Formulate a Hypothesis

The hypothesis must address the manipulated and responding variables

The cause and effect in your hypothesis are related to the independent and dependent variables in your question.

Example:

"How does the type of music affect a plant's growth?"

"I think that if a plant is exposed to classical music (IV), then it will grow very fast (DV)."

Formulate a Hypothesis

Right or wrong does not matter

At the end of the experiment you will find out whether your hypothesis was right or not. As a scientist, you should understand that it is not important that you "got it right." It is more important that you learned something about your topic. Don't get hung up on having the right answer.

Formulate a Hypothesis

Examples of good hypotheses:

I think that if a person reviews his or her class notes for 30 minutes each day, then his or her test scores will improve.

I think that if a person eats a healthy breakfast each day, then his or her writing skills will improve.

I think that if a plant receives light filtered through a green piece of plastic, then it will produce more leaves.

Objective 2 Quiz: Formulating a Hypothesis

Question: How does color influence people's food choices?

Hypothesis: I think that if people see a red sweater, then they will choose it over a different color.

"I think that..." is missing "If...then..." statement is not included Does not answer the question Good hypothesis

Objective 2 Quiz: Formulating a Hypothesis

Question: How does color influence people's food choices?

Hypothesis: I think that if people see a red sweater, then they will choose it over a different color.

Does not answer the question

Objective 2 Quiz: Formulating a Hypothesis

Question: How are paper towel brand names and absorbency related?

Hypothesis: If the brand name is expensive, then the absorbency will be higher.

"I think that..." is missing "If...then..." statement is not included Does not answer the question Good hypothesis

Objective 2 Quiz: Formulating a Hypothesis

Question: How are paper towel brand names and absorbency related?

Hypothesis: If the brand name is expensive, then the absorbency will be higher.

"I think that..." is missing

Objective 2 Quiz: Formulating a Hypothesis

Question: How does age affect a person's reaction time?

Hypothesis: I think that if a person is older, then he or she can react.

"I think that..." is missing Does not include both the MV and the RV from

the question "If...then..." statement is not included Good hypothesis

Objective 2 Quiz: Formulating a Hypothesis

Question: How does age affect a person's reaction time?

Hypothesis: I think that if a person is older, then he or she can react.

Does not include both the MV and the RV from

the question

Objective 2 Quiz: Formulating a Hypothesis

Question: How does the size of a wheel affect the speed of a HotWheels car?

Hypothesis: I think that if the car has large wheels, then its speed will be slower.

"I think that..." is missing "If...then..." statement is not included Does not include both the MV and the RV Good hypothesis

Objective 2 Quiz: Formulating a Hypothesis

Question: How does the size of a wheel affect the speed of a HotWheels car?

Hypothesis: I think that if the car has large wheels, then its speed will be slower.

Good hypothesis

Objective 2 Quiz: Formulating a Hypothesis

Question: How do different diet supplements affect a cat's coat?

Hypothesis: I think that using a brand-name diet supplement will make the cat's coat very shiny.

"If...then..." statement is not included "I think that..." is missing Does not include both the MV and the RV Does not answer the question

Objective 2 Quiz: Formulating a Hypothesis

Question: How do different diet supplements affect a cat's coat?

Hypothesis: I think that using a brand-name diet supplement will make the cat's coat very shiny.

"If...then..." statement is not included

Objective 3

ExperimentDevelop and follow a procedure.

Include a detailed materials list.The outcome must be measurable.

Carefully decide what your controlled variables will be

Before you do any designing, you must decide what variables will need to be controlled or kept the same in your experiment. Remember that you can change only one variable intentionally - the manipulated variable. Everything else must remain the same in your experiment or your results will be not be valid..

Tip #2:Decide what materials you will need to conduct the

experiment

Think about what you will be testing in your experiment and decide what materials you will need. Write all materials down in your log book. Be sure that the materials are ones to which you have easy access.

Once materials are listed, ask yourself how you will measure (or operationally define) your materials and results. If you are measuring length, use millimeters, centimeters, or meters. If you are measuring weight, use milligrams, grams, or kilograms. To measure volume, you must use milliliters or liters. Temperature must be measured in degrees Celsius. All measurements must be Metric.

Tip #3:Operationally define all variables before experimentingBefore you begin experimenting, you must ask yourself how you will operationally define your

variables. In other words, how will you measure them so that they can be put into number or quantitative terms?

If you are measuring growth of a plant, then how will you define "growth?" Is it the height of the plant (measured in millimeters or centimeters)? Is it the weight of the plant (grams)? In your experiment, does growth refer to the size of the leaves? Whatever you want growth to be in your experiment must be clearly defined ahead of time. Write down all measurements you will use to define each variable operationally.

Tip #4:List all procedures in the order in which they will be completed

Once you decide which variables need to be controlled, what materials you will need, and how you will operationally define your variables, you must list all the procedures you need to complete in order to conduct the experiment.

Starting from the very beginning, list all of your procedures in order. Include many details. Include how you will control variables. Write down how you will measure your results.

Your finished procedures should be detailed so that anyone who wants to duplicate your experiment can do so simply by following your list.

Example of how you should design your experiment:

1. Question: How does the amount of water affect the growth of a plant?

2. Hypothesis: I think that if a plant receives too much water, then the plant will become unhealthy or die.

3. Experiment design:

Controlled variables: Type of plant, age of plant, size of pot, amount of soil, type of soil, amount of sunlight, type of water provided, time of day that growth is measured

Materials needed: 5 small, identical plastic pots, bag of soil, bean seeds, water, measuring cup, sunny window

Operational definitions: Water will be measured in milliliters. Plant growth will be measured using centimeters. I will measure from the soil to tallest part of the plant.

Example of how you should design your experiment:

Procedures:

1. Measure 300 ml of soil and pour into plastic pot. Repeat for each pot.

2. Place 3 bean seeds on the top of the soil in each pot.

3. Measure 100 ml more of soil and sprinkle over beans. Repeat for each pot.

4. Place all 5 pots in a sunny window. All pots should be positioned to receive the same amount of light.

5. Label each pot with a number using a magic marker. Pots will be numbered 1 - 5.

6. Measure 10 ml of water and pour into pot #1. Measure 20 ml of water and pour into pot #2. Put 30 ml in pot #3, 40 ml in pot #4, and 50 ml in pot #5.

7. Record date in log book along with water measurements for each pot.

8. Check plants at the same time every day. Measure and record height for each plant daily.

Quiz for objective 3

Question: How does color influence people's food choices?

Hypothesis: I think that if people see a red cookie, then they will choose it over any other color of cookie offered to them.

Controlled variables: Type of cookie, color of cookies, age and gender of people being offered cookies, size and shape of cookies, temperature of cookies, "doneness" of cookies.

Correct One of the variables listed should not be included More variables need to be controlled These are not controlled variables

Quiz for objective 3

Question: How does color influence people's food choices?

Hypothesis: I think that if people see a red cookie, then they will choose it over any other color of cookie offered to them.

Controlled variables: Type of cookie, color of cookies, age and gender of people being offered cookies, size and shape of cookies, temperature of cookies, "doneness" of cookies.

One of the variables listed should not be included

Quiz for objective 3

Question: How does color influence people's food choices?

Hypothesis: I think that if people see a red cookie, then they will choose it over any other color of cookie offered to them.

Materials: sugar, flour, milk, butter, food coloring (blue, red, yellow, and green), oven, cookie sheet, cookie cutter, bowls, spoons, spatula, measuring cups, serving tray, 10 girls who are 11 - 12 years old.

Correct Material list does not fit the problem or hypothesis Some materials listed are not necessary Some materials are missing

Quiz for objective 3

Question: How does color influence people's food choices?Hypothesis: I think that if people see a red cookie, then they

will choose it over any other color of cookie offered to them.Materials: sugar, flour, milk, butter, food coloring (blue, red,

yellow, and green), oven, cookie sheet, cookie cutter, bowls, spoons, spatula, measuring cups, serving tray, 10 girls who are 11 - 12 years old.

Correct

Objective 4: Conducting the Experiment

Tip #1:Always keep variables in mind

Don't forget that the only variable that you are changing in your experiment is the manipulated variable. Everything else must remain exactly the same.

Conducting the Experiment

Tip #2:Follow your procedures

Take each step of your experiment one at a time. Stick to the procedures that you wrote down in step 3. Make sure you complete the procedures in exactly the same way for each test you conduct.

Objective 5:Collecting Data

Tip #1:Keep raw data in your log book

Raw data is the first information you get as you make observations during your experiment. For example, if you were charting plant growth, you might find that on the sixth day of the experiment, the plant has grown to a height of 1 cm. On the next day, it is 1.5 cm. Then the following day the plant is 1.7 cm. All of this information is raw data. It needs to be kept in your log book.

Collecting Data

Tip #2:Construct a data table to record data easilyA data table is the easiest way you can record your information. It

looks like the diagram below. The manipulated variable is always placed on the left side of the table, and the responding variable is always located on the right side. When you get your data, simply put it into the table.

Collecting Data

Tip #2 Continued:Construct a data table to record data easilyWhen you record data in a table, be sure to list the manipulated variable

numbers in the left column from smallest to largest. Also, the numbers for the manipulated variable should fall into a pattern (for example, by ones - 1, 2, 3, 4, 5; by fives - 5, 10, 15, 20, 25; by hundreds - 100, 200, 300, 400, 500). Look at the example below:

Collecting Data

Tip #3:Use a data table to help make a graph

Once you have collected your data in a table, it will be very easy to create a graph in Step 6. Keep all data written neatly in your log book.

Objective 6:

Graphing Data

Tip #1:Transfer information from the data table to your graph

Take the raw data from your data table and use the exact same numbers in your graph. Remember that you must keep the number from the manipulated variable side with its counterpart on the responding variable side. These two matching numbers are called ordered pairs, and they cannot be separated from one another. They always go together.

Objective 6:

Graphing Data

Tip #2:Put your MV on the x axis and RV on the y axis

The horizontal axis (or x axis) on a graph shows the manipulated variable. Therefore, you must write your MV just below the x axis on your graph. The vertical axis (or y axis) represents the responding variable in your experiment. Write your RV to the left of the y axis on the graph. Look at the graph below to see how to label each axis.

Objective 6:

Graphing Data

Tip #3:Include operational definitions for the MV and RV on the graph

Once you label the manipulated and responding variables on your graph, you must also include how you will operationally define each of these variables. For example, if you are measuring length, you might operationally define the variable with millimeters, meters, or kilometers. Be sure to use abbreviations when operationally defining variables, and only use Metric measurements.

Objective 6:

Graphing Data

Tip #4:Use a pattern of numbers for each axis on your graphA pattern of numbers must be established for each axis. This pattern must cover the smallest and

largest numbers in your manipulated and responding variables. A pattern is a series of numbers that adds an equal amount for each successive number. Look at the examples of number patterns below.

Pattern by ones 1, 2, 3, 4, 5...

Pattern by twos 2, 4, 6, 8, 10...

Pattern by fives 5, 10, 15, 20, 25...

Pattern by twenties 20, 40, 60, 80, 100...

Pattern by hundreds 100, 200, 300, 400, 500...

Objective 6:

Graphing Data

Tip #5:Plot data when you finish labeling the graphTo plot data, start with the x axis and find your first number under the MV column

on your data table. In the table below, the first number is 2. Then, on the y axis, find the corresponding number from the RV column on your data table. In the table below, the corresponding number is 14. Draw one imaginary line up from the x axis and another imaginary line to the right on the y axis until the two lines intersect. The point of intersection is where you should plot your point. Repeat this process for all of your ordered pairs on the data table.

Objective 6:

Graphing Data

Tip #5 continued:.

Objective 6:

Graphing Data

Tip #5 continued:.

Objective 6:

Graphing Data

Tip #6:Add a title to the finished graphThe title of your graph must relate directly to your

manipulated and responding variables. It is a good idea to include both the MV and RV in the title.

Objective 7 Quiz:Drawing Conclusions

Tip #1: Summarize the facts you gathered from your experiment

Now that you have finished all the other parts of your experiment, it is time to look at the data you have gathered. By examining the facts you learned, you can easily relate them back to your question and hypothesis from steps 1 and 2. Drawing a conclusion involves telling whether your hypothesis was correct or not.

Objective 7:

Drawing Conclusions

Tip #2: Explain how the manipulated variable affected or

changed the responding variable

The best way to write a conclusion is to tell how your manipulated variable influenced (if at all) your responding variable. The point of your experiment was to see if the MV would affect the RV. Explain what you found out about the relationship of the MV and the RV.

Objective 7:

Drawing Conclusions

Tip #2 Continued: Explain how the manipulated variable

affected or changed the responding variable

Let's say your question was "How does the amount of light that a plant receives affect its growth?" Your hypothesis was "I think that if a plant receives a lot of light, then it will grow more." Let's assume that this is what you found out:

Objective 7:

Drawing Conclusions

Tip #2 Continued:

Objective 7:

Drawing Conclusions

Tip #2 Continued: Explain how the manipulated variable affected or

changed the responding variable A good conclusion might be as follows:

Plants that receive too much light do not grow well. Findings indicate that the ideal amount of light for a plant is about 12 - 14 hours per day. In this experiment, fourteen hours of light produced the greatest amount of growth.