How do look at problems? Do you give up when faced with a problem?

How do look at problems? Do you give up when faced with a problem?Do problems cause you to ask more questions?

In this class and in life you will face many problems. How you fight the problems makes all of the difference in the world--- and in this class.

Designing an Experiment

When observe an event and you wonder why, you may have the opportunity to come up with a solution, and then test it!This is what happens when we design experiments.

Step 1• Ask a question. • A good question is one you can solve or answer by

the process of testing.• Clear and testable• Good question: Can plants grow without soil?• Bad question: What is the best way to grow plants.

What is “best”? Who knows? That is difficult to define.

This is also called a testable question.

Step 2 • Form a hypothesis• A Hypothesis is a prediction with a reason. Write

your hypothesis in “IF… Then… because form”• If (describe manipulated variable) then (describe

responding variable) because (say what you know about science that explains why you think this will happen)

• Example: If I give a plant no water then it will wilt and die because plants need water for photosynthesis and photosynthesis is necessary for life.

Step 3• Design An Experiment

o Identify your variables.o Identify your controlo Plan your procedure

Variables• Manipulated (Independent

Variable): • The one thing you change in

the experiment to see if it makes a difference.

“We changed the _________.” make sure it’s the one thing that’s different about your set ups) • Example: For the water and

plant experiment used previously, the manipulated variable is water, or amount of water.

• Responding (dependent Variable):

• is the response we are looking for to see if our change made a difference.

• Usually it is something we measure and/or record as data.

• Example: For the water and plant experiment used previously, the responding variable is the condition of the plant—wilted, dead, firm crisp leaves, alive…

Experimental Control• Experimental control: make sure it

describes the set up of “normal conditions”• This is the set up in the experiment that you

do not “do” the independent variable to.

Example: If testing how water effects plant growth, this is the plant in the experiment that receives the recommended dose of water.

Controlled Variables• Controlled Variables: are conditions in the

experiment that stay the same. • We control them because we don’t want them to

cause any unwanted changes. • We only want to test one factor/condition at a time

(our manipulated variable):• Example: For the water and plant experiment used

previously, the controlled variables might be using the same type of plant, same kind of soil, plants receive the same amount and type of light, the plants experienced the same temperature during the testing period.

Validity Measures• Validity measures: these are things we do in

an experiment to make sure our experiment is valid and useful.

• Some call validity measures “quality assurance.”

• We don’t want to ruin our results by being careless.

• What things do we do to be careful that could effect our results?

• In most cases, additional controlled variables could be listed as validity measures.

Procedure• When you write your procedure, make it

clear and detailed.• The goal is REPLICATION?

o Could another scientist repeat the experiment exactly how you did it?

Record Data• Use a data table to record your results.

o Record all results, even if they don’t fit your prediction. This is called intellectual honesty.

• Later, you may want display your results in a graph.

Analyze Data & make a conclusion• I results support your hypothesis, you

hypothesis was supported.• If results do not support your hypothesis,

your hypothesis was refuted.

• Do not say, right, wrong, correct, incorrect.

Conclusion parts

3 parts:• “My hypothesis was supported” or “My

Hypothesis was refuted”• Use actual data from your results and

explain the math you used to come to your conclusion.

• Summary statement. List questions that come from running this experiment that should be tested later

Replication• The last step in the scientific process is

replication.• Other scientists can repeat the

experiment and provide data that further supports or refutes the hypothesis.

Try thisThere was once a high school student who wanted to know if wearing cologne would help him to get girls to go on dates with him.He predicted that it would help him. He ran an experiment to see if his hypothesis was supported. One day, he came to school wearing no cologne. As he talked to girls, he noted how many he asked out and how many said yes.The next day, he wore the same clothes, chewed the same gum and did everything the same. But, this time, he wore cologne. He recorded the number of girls he talked to and how many times girls said yes.

Choose one answer from the right and one from the left for each slide. A: “normal” conditions, no changeC: These things stay the same throughout the entire experiment.E: Predicting a resultG: Deciding whether or not your hypothesis is supported or refuted.I: The thing that you changed.K: Expected result

B: A guy wearing cologne.D: Talking to the girls wearing no cologne, changing nothing.

F: Wearing the same clothes and acting with the same attitude

H: A girl agrees to go on a date with a guy.

J: “Guys will get many dates if they wear cologne”

L: The hypothesis is supported. Wearing cologne really helps guys get dates!

HypothesisA: “normal” conditions, no changeC: These things stay the same throughout the entire experiment.E: Predicting a resultG: Deciding whether or not your hypothesis is supported or refuted.I: The thing that you changed.K: Expected result






Independent VariableA: “normal” conditions, no changeC: These things stay the same throughout the entire experiment.E: Predicting a resultG: Deciding whether or not your hypothesis is supported or refuted.I: The thing that you changed.K: Expected result






Dependent VariableA: “normal” conditions, no changeC: These things stay the same throughout the entire experiment.E: Predicting a resultG: Deciding whether or not your hypothesis is supported or refuted.I: The thing that you changed.K: Expected result






Controlled VariablesA: “normal” conditions, no changeC: These things stay the same throughout the entire experiment.E: Predicting a resultG: Deciding whether or not your hypothesis is supported or refuted.I: The thing that you changed.K: Expected result






Control Set upA: “normal” conditions, no changeC: These things stay the same throughout the entire experiment.E: Predicting a resultG: Deciding whether or not your hypothesis is supported or refuted.I: The thing that you changed.K: Expected result






ConclusionA: “normal” conditions, no changeC: These things stay the same throughout the entire experiment.E: Predicting a resultG: Deciding whether or not your hypothesis is supported or refuted.I: The thing that you changed.K: Expected result






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How do look at problems? Do you give up when faced with a problem?