The Scientific Method

6 Important Steps Purpose/ Question Research your topic(s) Form a hypothesis (based on your research) Procedure Analysis Draw a conclusion (based on your data)

What is the Scientific Method? It is a process that is used to find answers to questions about the world around us.

Is there only one “scientific method”? NO!  there are several versions Some versions have more steps while others may have only a few. All begin with the identification of a problem or a question to be answered based on observations around us and provide an organized method for conducting and analyzing an experiment.

Steps to Solving a Problem (The Scientific Method) Identify the Purpose/Problem State the problem to be solved or the question to be answered. Collect Information/Research Obtain facts and ideas from books, journals, internet, etc. that provide insight regarding your problem/question. Cite these resources. Form a Hypothesis Based on the information/research you collect, propose a solution or “best guess” that will help guide your experimentation and attempt to answer the proposed problem/question. Test Your Hypothesis – “Procedure” Describe, design, and conduct an experiment that will give you information or data that supports (or not) your hypothesis. Accept or Reject Your Hypothesis – “Analysis” Determine whether your data/results from the experiment supports (or not) your hypothesis; if not, it may be necessary to review your information/research and revise your hypothesis. Report Your Results – “Conclusion” Formulate a conclusion that answers the original question from step one and share the results with the scientific community (or the community at large).

Step 1: Identify the Purpose/Problem What do you want to learn from the experiment?

Purpose Written as a question - called the “BIG QUESTION” Purpose includes three components 1. It is clearly written 2. It usually starts with the verb “does.” 3. It can be answered by measuring something

Purpose (cont.) A good topic can be tested!!! It is important the topic isn’t too general Example: Too General Good Topic meal worms food meal worms eat

Topic Purpose plant growth rates Does fertilizer affect the growth rate of plants? fireflies’ flash rates Does temperature affect the flash rate of fireflies? paper airplanes’ Does the design of a paper design airplane affect its hang time?

TEST YOURSELF Topic Too General/Good 1. best brand of batteries 2. volcanoes around the world 3. water conservation 4. materials used as insulators Topic Purpose 5. temperature and bread mold 6. texture of a paper towel 7. colored light and plant growth 8. light and the activity of meal worms

What is already known about the topic? Step 2: Research What is already known about the topic? Start by identifying key words in the purpose Look up the key word in an encyclopedia, dictionary, or textbook Then, expand the research to the internet THE GOAL IS TO FIND INFORMATION THAT WILL HELP IN FORMING A PREDICTION ABOUT WHAT WILL OCCUR IN THE EXPERIMENT!!!

RESEARCH EXAMPLE Does fertilizer affect the growth rate of a sunflower? Key Words: fertilizer and sunflower Fertilizer Sunflowers Why do we need fertilizer? Why does soil type affect plant growth? How do fertilizers affect plant growth? How do minerals and nutrients affect plant growth? Who invented fertilizer? Who would be a good resource in my community to contact about plants? What are the ingredients in fertilizers that affect plant growth? What are the elements required for plant growth? When do plants need fertilizer? When does photosynthesis affect plant growth? Where should fertilizer be applied to the plant to get the best results? Where in the plant does photosynthesis occur?

RESEARCH: TEST YOURSELF Underline the key words for each purpose below. Does the depth a seed is planted affect its ability to sprout? Does eating breakfast affect short-term memory?

RESEARCH: TEST YOURSELF II. Write questions to direct the research for the purpose: Does temperature affect the strength of a magnet? Temperature Magnet Why How Who What When Where

Step 3: Hypothesis What do you think will happen in the experiment? -follows a set pattern -answers question stated in the purpose - it is brief and to the point - makes an educated guess or prediction

Example: Purpose: Does the depth of a seed affect its sprouting time? Hypothesis: If there is an increase in the depth of a seed, then the sprouting time will also increase. Hypothesis… is worded so that it can be tested Identifies the independent and dependent variables independent: factor that is changed in an experiment (depth of seed) dependent: factor that responds to the change. The change is measured and recorded in metric units. (sprouting time)

HYPOTHESIS EXAMPLE If water temperature increases, then the amount of sugar dissolved in the water will also increase. Independent Variable: water temperature Dependent Variable: amount of sugar that dissolves, measured in grams

Hypothesis Test Yourself Purpose: Does fertilizer affect the growth rate of a plant? Hypothesis: _______________________ Hypothesis: Warmer water temperatures will increase the heart rate of fish. Independent Variable: _______________ Dependent Variable: ________________

Step 4: Procedure How will you test the hypothesis and record the results?

Procedure Procedure is a step-by step set of directions for testing the hypothesis. A good procedure is so detailed and complete that other scientists can duplicate the experiment.

Procedure involves several components. Materials - list of items needed to conduct experiment Experiment - test designed to answer the question stated in the purpose The test consists of two groups Experimental group: includes the part(s) of the experiment that are changed and tested. Control group: includes the part(s) of the experiment that are left unchanged

The test consists of two groups Experimental group: includes the part(s) of the experiment that are changed and tested. Results compared to the control group. Control group: includes the part(s) of the experiment that are left unchanged. The conditions a scientist wants to remain the same during an experiment are called the constants.

Variables are certain things a scientist changes to see how they affect the experiment. Independent Variable: The factor that is changed and tested in the experiment. A good experiment only has one independent variable Dependent Variable: The factor that responds to the change. The change is measured in metric units. Data: record of the results of the experiment, usually recorded in a data table. Later, data is organized in a graph to make the information easier to read and analyze.

Step 5: Analyze (Interpret) Data What do the results tell about the experiment? This is where the data is organized using a graph to make the information easier to read and analyze.

Basic Parts of a Graph Graph Title Axes and Their Labels -Horizontal axis (x-axis) shows the Independent Variable -Vertical axis (y-axis) shows the Dependent Variable Scale - the range of values being represented, placed at equal intervals along vertical axis

Do the results support your hypothesis? Step 6: Conclusion Do the results support your hypothesis?

Conclusion Summarizes the results Includes purpose, a brief description of the procedure, and whether or not the hypothesis was supported by the data Uses key facts from research to help explain results Results don’t always support hypothesis It’s OK!! This can lead to a new hypothesis and designing a new experiment