Scientific Method

The Scientific Method

Practice Scenarios

Al’s salt water experiment

Al wonders if adding salt to water will affect how long it takes the water to freeze. He thinks that salt water will freeze more quickly than fresh water. He decides to check his hypothesis by conducting an experiment.

Multiple Choice

What would be the Independent Variable in Al´s experiment?

• The time it takes the water to freeze.

• The container the water is placed in.

• The type of water

• The amount of water

Multiple Choice

What would be the Dependent Variable in Al´s experiment?

• The time it takes the water to freeze.

• The container the water is placed in.

• The type of water

• The amount of water

Multiple Select

What would be the Controlled Variables (Constants) in Al´s experiment?

• The time it takes the water to freeze.

• The container the water is placed in.

• The type of water

• The amount of water

Al’s salt water experiment

A hypothesis is an educated guess of what will happen. It must show a cause and affect relationship.

In this experiment Al thought the salt water would freeze more quickly than fresh water.

Open Ended

Write a hypothesis for Al in an If...then...statement that shows a cause and effect relationship.

Al’s salt water experiment

To test Al´s hypothesis, he takes two ice trays and fills one with distilled water and the other with distilled water that has two tablespoons of salt added. He makes sure he puts exactly the same amount of water in each ice tray. He takes the trays and puts them side by side in the freezer. He checks the ice trays every 10 minutes to see if the water in each tray has begun to freeze. Al finds that after 20 minutes the water in the ice tray without the salt has started to form ice, while the ice tray with the salt water is still completely liquid.

Multiple Choice

Was Al´s hypothesis supported by his data?

• Supported

• Partially Supported

• Not Supported

Peter's Musical Experiment

Peter loves music. He believes that he does his homework better and faster when he listens to music. His parents say that music is distracting when studying.

Multiple Choice

What would Peter's Independent Variable be?

• Listening to music

• Homework score

• How long it takes to finish his homework

• Distractions in the study area

Multiple Select

What would Peter's Dependent Variable be? (careful...there could be more than one)

• Listening to music

• Homework score

• How long it takes to finish his homework

• Distractions in the study area

Multiple Select

What would be a controlled variable for Peter's experiment?

• Type of homework assignment

• Homework score

• How long it takes to finish his homework

• Distractions in the study area

• Listening to music

Look for the Independent and Dependent Variables.

Multiple Choice

What was the independent variable in the germination experiment?

• Type of Seeds

• Amount of Water

• Amount of Light

• Amount of Heat

Open Ended

What was the dependent variable for the germination experiment?

If I increase the amount of water given to seed B then more seeds will sprout.

Use the image on the next slide to determine if the hypothesis above would be supported or not?

If I increase the amount of water given to seed B then more seeds will sprout.

Multiple Choice

According to the data given, the hypothesis was...

• Supported

• Partially Supported

• Not Supported

Look for the Independent and Dependent Variables.

Multiple Choice

In the "growing plants" experiment, what was the independent variable?

• Height of the Plant

• Amount of Light

• Amount of Water

• Type of nutrients in the soil

Multiple Select

In the "growing plants" experiment, what were the dependent variables?

• Height of the Plant

• Amount of Light

• Mass of the Plant

• Type of nutrients in the soil

Multiple Select

When conducting an experiment, why is it important to complete multiple trials of the same exact set-up?

• To obtain accurate data.

• To obtain consistent data

• To eliminate the effects of outliers (unusual data).

• To obtain data that will support your hypothesis.