Scientific Method
Variables
Observation vs. Inference
Variables II
Scientific Method Applied
100
What are the steps of the scientific method?
1. State problem 2. Research Topic 3. Form Hypothesis 4. Test Hypothesis 5. Analyze Data 6. Form conclusion
100
Define the word "variable"
Anything in the experiment that can change.
100
What is an inference?
Using your observations to make a guess about an object or an outcome.
100
When Mr. Han use more force to throw the ball, the ball traveled further across the room. What is the independent variable? What is the dependent variable?
IV- amount of force DV- distance ball move
100

Read the following experiment and state a good hypothesis. I am doing a test to see if there is a connection between how long you run and how fast your heart beats. I will be performing an experiment where a person will run for a 1 minute and I will check their heartbeat. Then they will run for 2 minutes and I will check their heart rate. I will do this up to 6 minutes and see if there is a connection. What do you think my hypothesis should be?

What is...If I increase the amount of time I run, then my heartbeat will increase.

200
What do scientist do to test a hypothesis?
Perform an experiment
200
What is an independent variable?
The variable in the experiment that you change to test.
200
This surface feels slippery. Is this statement an observation or an inference? Why?
Observation, you are using your sense of touch to get information.
200
When Mr. Han use more force to throw the ball, the ball traveled further across the room. List two control variable for that situation.
style of throw type of ball location point of release
200

List the independent and dependent variables in the following hypothesis. If soil temperatures rise, then plant growth will increase.

What is...Independent-soil temperatures, Dependent-plant growth.

300
What do you do when you make an observation?
use your sense to collect information
300
What is a dependent variable?
The dependent variable is the variable that responds to the independent variable.
300
This footprint was made by a dinosaur. Is this statement an observation or an inference?
Inference, you are guessing its a dinosaur that made the footprint.
300
When John increases the amount of time to study, usually his test scores increase as well. What is the independent variable? What is the dependent variable?
IV- amount of study time DV- test score
300

Thinking about the hypothesis: If soil temperatures rise, then plant growth will increase. What might a control in this experiment be?

What is... using the same potting soil, making sure both plants have an equal amount of light etc.

400
What's the difference between quantitative and qualitative observation? Give example of both.
QNT- observation using numbers, QL- observation without using numbers.
400
What type of variable represents "cause" and what type of variable represents "effect"?
Independent Variable (cause) -------> Dependent Variable (effect)
400
Mr. Han came into class looking all wet. The students thought that he got caught in the rain and ran instead of walked to school. What part of this statement is an observation and what part is an inference? Explain.
Observation- "Mr. Han came into class looking all wet." Inference- "The students thought that he got caught in the rain and ran instead of walked to school."
400
Mr. Han thinks that the "Quantum" Duracell battery has more energy than the regular Duracell battery. He wants to test out his hypothesis by doing the following experiment. He will use one new "Quantum" battery to power a flashlight and a old regular battery to power a clock. He leaves the flashlight and clock on until it turns itself off. He will record the time. Is this experiment considered a controlled experiment? Explain.
It is not a controlled experiment because there is more than one independent variable.
400

Find the independent and dependent variables in the following experiment: If you increase the number of times you practice shooting free-throws, then you will increase your chances of making a basket every time.

What is Independent- practice shooting free throws, Dependent- making baskets.

500
There are 1126 students in MS 74. Ouantitative or qualitative observation? Why?
Quantitative observation because describe something using numbers to quantify.
500
What makes an experiment considered a controlled experiment?
The experiment has one independent variable (cause), one dependent variable (effect) and the rest are control variables.
500
When can you use observation in the Scientific Method? When can you use inference in the Scientific Method?
Observation- Research, Perform an Experiment, Analyzing Data Inference- Form hypothesis, Form conclusion
500
Mr. Han thinks that the "Quantum" Duracell battery has more energy than the regular Duracell battery. He wants to test out his hypothesis by doing the following experiment. He will use one new "Quantum" battery to power a flashlight and a old regular battery to power a clock. He leaves the flashlight and clock on until it turns itself off. He will record the time. How can you make this experiment into a control experiment?
Both batteries are new. Both batteries being used with the same device. Only thing that changes is the type of battery.
500

During gym class Sally noticed that her friend Melissa always ran faster than her. Sally knew that they exercised equally, so she wondered what could cause Melissa to run so fast.

Sally began to compare herself and Melissa to see what could cause the difference in speeds. She noticed that Melissa was taller and wondered if height affected speed. Sally predicted that taller people were able to run faster, but wanted to check her prediction. She asked her gym teacher if she could test her idea.

Sally measured all of her classmates’ height in centimeters and recorded it in her chart. Each classmate then ran one kilometer while Sally timed them with a stopwatch and recorded the data in seconds. She then began to review her data and look for the answer to her question.

1. What question is Sally trying to answer? 

Does height affect speed ?

Dependent Variable- measured 

(DV) classmates height 


Independent Variable tested 

(IV) Speed of classmates

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