Drill – September 10, 2009

1. Drill – September 10, 2009 Answer the following questions on the sheet provided. • What is a scientific method? • List at least four steps that any scientific method should include. • List at least threecriteria that a ‘good’ hypothesis meets. Try to do this without your notes, but you may consult them if you get stuck.

2. Scientific Methods An Introduction to “Doing” Science September 10, 2009

3. Objectives • At the conclusion of this lesson, a student will be able to: • explain what makes an experiment ‘controlled.’ • determine the difference between an independent, dependent, and controlled variable by identifying each in a demonstrated experiment. • Key Terms: • controlled experiment, experimental group, control group, variable, independent variable, dependent variable, controlled variable, quantitative data, qualitative data

4. Experimental Apples Problem: What is the best way to keep apple slices from turning brown after you cut them? • Observations: • Apples usually turn brown after you cut them or bite them. • Sometimes apples turn brown when they have a bad spot. • The brown color does not occur everywhere. • Inferences: • The brown color only occurs when the apple is damaged in someway. • The brown color occurs when the inside of the apple comes in contact with the air. • Research: How Stuff WorksScientific American

5. The Purpose of an Experiment • A controlled experiment is any procedure created to test a hypothesis in a controlled setting. • experimental group – the group receiving the factor being tested • control group – the group not receiving the factor being tested (used for comparison)

6. A Word About Variables • Any factor that can change in an experiment is called a variable. • An independent variable is tested during an experiment. There is usually only one. • Often called the experimental variable. • The dependent variable changes because of changes made to the independent variable.

7. Controlled Experiments A controlled experiment is one in which all of the variables are held constant except one. These constant variables are called controlled variables. What are some of the controlled variables in today’s experiment?

8. Collecting Data • data – information gained from your observations • quantitative – data collected as numbers • qualitative – data collected as descriptions of observations (i.e color, behaviors, odors) Will our apple experiment collect quantitative or qualitative data?

9. Effect of Various Substances on Apple Browning

10. For Homework Identify the Controls and Variables with the Simpsons! Read the passages on the worksheet Complete the questions to the right of the passage using your notes from today.

11. Work Cited Biggs, Alton, and et. al.. Biology. New York: Glencoe McGraw-Hill, 2007. Unit 1 Resources - Ecology. New York: Glencoe McGraw-Hill, 2007.