Topic: Variables and Controls (ISN 23) EQ: What is scientific inquiry?

1. One way scientists find out about the world around us. The scientific method is 2. A way scientists answer a specific question.

Problem/Question Observation/Research Formulate a Hypothesis Experiment Collect and Analyze Results Conclusion Communicate the Results

Steps of the Scientific Method Step four of the Scientific Method ExperimentExperiment: Develop and follow a procedure. Include a detailed materials list. The outcome must be measurable (quantifiable).

Experiment Experiments include factors that have to be tested. These are called variables.All Experiments include factors that have to be tested. These are called variables.

What is a Variable?

DEFINITION  Variable – Any factor that can change in a scientific investigation or experiment  2 types of variables

Types of Variables 1. Test/Independent Variable  The condition that is intentionally changed by the investigator in an experiment  There can be only one in an experiment  Ask the question: What are we changing?

2. Outcome/Dependent Variable The factors or conditions that will change  The factors that you measure or observe as data  There can be one or more  Ask the question: What am I trying to observe or measure? Types of Variables

Controlled/Control Group  The factors or conditions that are kept the same (unchanged) in an experiment.  There are many controlled variables in an experiment Types of Variables

Identify variables for the following experiments. You can do it! Practice

Does changing the temperature of a ball affect the height the ball will bounce? Testable Question #1 HotCold

Test/Independent Variable Outcome/Dependent Variable Identify Variables #1 ColdHot Does changing the temperature of a ball affect the height the ball will bounce?

Controlled Variables: * Same ball * Dropped from the same height * Dropped onto the same surface * etc… Identify Variables #1

Does changing the color of light affect the growth rate of plants? Testable Question #2

Test/Independent Variable Outcome/Dependent Variable Identify Variables #2 Does changing the color of light affect the growth rate of plants?

Controlled Variables: * Same type / size of plant * Same wattage of bulb * Same amount of water * Same soil * Light on for the same amount of time * etc… Identify Variables #2

How does the size of a parachute affect the time it takes a hippo to fall 10 feet? Testable Question #3

Test/Independent Variable Outcome/Dependent Variable Identify Variables #3 How does the size of a parachute affect the time it takes a hippo to fall 10 feet?

Controlled Variables: * Same hippo * Dropped from the same height * Same parachute fabric * Same length of strings on the parachute * etc… Identify Variables #3

What is the change variable in the experimental setup on the next page—what is the one thing the experimenter has changed with plant 1, 2 and 3?

In this case, the experiment is changing the amount of water that the plant receives each day.

Summarizing Activity (ISN 22) Complete the Simpsons Controls and Variables activity