The Scientific Method

What is the scientific method? It is a logical, systematic approach to solve a problem It is a logical, systematic approach to solve a problem The scientific method is a set of steps used by the scientific community to organize thoughts in order to solve or investigate problems. The scientific method is a set of steps used by the scientific community to organize thoughts in order to solve or investigate problems.

The Steps of the scientific method 1. Identify the problem and make observation 2. Form a hypothesis 3. Design an experiment 4. Test your hypothesis (conduct experiment) 5. Draw conclusions

Step 1 Identify the problem This is always the first step This is always the first step Ask yourself, Ask yourself,  What am I trying to figure out in this investigation?  What can I learn through my Observations?  Observation is made by using your senses  Sight, smell, touch, taste, hearing Problem should be related to observation that you or someone else can make during the investigation. Problem should be related to observation that you or someone else can make during the investigation. The problem is written in the form of a question. The problem is written in the form of a question.

Quick Example Title: The effect of pH on pansy growth Problem: Will the pH of the water effect the growth of the plants?

Gather information  Gather information related to the question  Use the “need to know” to get you started  Research, Research, Research !!!!  This step could answer the question for you or make you realize that this question is not appropriate for scientific study

Where do we go from here?  Once we know the problem, then we have to look at gathering information to support our problem.  Ask yourself two questions…. What do we know already?  Think of five to ten things you already know about your problem.  What do we need to know?  Now what are five to ten things you need to find out?

Let’s do it together  What I know  Plants need water to grow  The water has different pH levels  The plants need sunlight  The plants need the same temperature  All of the plants are the same.  What I need to find out  What is pH?  What is the difference in a level 2, 7 and 9 on a pH scale?  How much water should I give each day?  What temperature does the plants need to be placed in for them to grow?  How much sunlight do I need?

Form a hypothesis  Form a hypothesis based upon the research and/or previous knowledge.  Remember:  A good hypothesis is one that you can test  A hypothesis is a possible answer to your question  A hypothesis is always in the form of a statement, never a question (you already have one)  It is usually in the form of IF….Then….Because

How do I write a Hypothesis?  A hypothesis is written in an (if…then...because…) statement  If…tells what you did in the experiment (verb)  Then….tells the action what happen next (reaction)  Because…..Explanation of the reaction  “If………, then………because…..” statement  Example:  If I flip the light switch to on then the light will come on because the switch allows power to go to the light.

Quick Example Title: The effect of pH on pansy growth Problem: Will a plant grow with too much acid in the water? Hypothesis: If pansies receive water below pH of 7, then they will not grow because the acid in the water will kill the flower.

Design an experiment  Why Design an experiment?  Design an experiment to test your hypothesis  WAIT…Look at this first If this impossible, then you do not have a good hypothesis  Go back to step 2 (forming a hypothesis)  If it is possible, then Keep going……

Materials What do you need to perform this problem? What do you need to perform this problem?  Use list or bullets (it is easer to read)

Quick Example Title: The effect of pH on pansy growth Problem: Will a plant grow with too much acid in the water? Hypothesis: If pansies receive water below pH of 7, then they will not grow because the acid in the water will kill the flower. Materials: 27 of the same flowers 27 pots of the same size Measuring cup Water source Measuring tape Pen and paper

Parts of an experiment  Control  Constant  Variables  Independent  Dependent  Replication (repeating the experiment MANY Times

Control  Every experiment must have a control group that will be used for comparison with one or more experimental groups

Constants The constants are the things that are will stay the same in the control and experimental group. The constants are the things that are will stay the same in the control and experimental group. The control is identical to the experimental group in all aspects but one variable that is being studied The control is identical to the experimental group in all aspects but one variable that is being studied

Variables  The variables are the things that change during the experiment.  The variable that is being manipulated by the experimenter is called the independent variable  The thing that changes in reaction to the independent variable is the dependent variable  Both variables are often found in the title and hypothesis.

Data Collection (results)  Make observations and collect data  This involves taking notes, measurements, as you are conducting your experiment  Descriptive or qualitative data uses written descriptions of what is observed.  Numerical or quantitative data uses measurement that can be recorded in a table or chart  Most data gathering should include both descriptive (qualitative) and numerical (quantitative) data

Gather data *measure each plants height daily *place data in tables, graphs Day1Day2Day3 pH2 pH7 pH8

Analyze data  What is the data telling you?  This occurs when experiment is over  Data and observations already made are now analyzed to determine cause and effect  Numerical data from the table or chart is placed in a graph  All results must be backed up with data from the experiment

Analyze Data

Form a conclusion  Was the hypothesis supported by the data?  Explain why or why not  Is more data needed?  Explain why or what data is needed  Should a new hypothesis be made and tested?  Explain why a new hypothesis is needed  Does the data lead to more questions that can be explored or tested?  What are the questions and why  Did some problem contaminate the data?  Explain what happen  Should be experiment be repeated?  Why do you feel it should or should not