WELCOME Please bring supplies as soon as you can I suggest reviewing yesterday’s notes

Intro: How do you know that an experiment is good? In other words, what are some characteristics of good experiments?

DESIGNING AN EXPERIMENT Most experiments involve two groups: I. EXPERIMENTAL GROUP: Only one condition (variable) is changed Independent (manipulated) variable = the condition changed by the experimenter Dependent (responding) variable = the condition that changes because of the independent variable

Hmm… In the following experiment, identify the independent and dependent variables. Mrs. Pumpkin wants to know how much fertilizer to use on her roses for best growth. She divides her rose garden into three sections. She fertilizes section A once per year, section B twice per year and section C three times per year.

Hmm… In the following experiment, identify the independent and dependent variables. Mrs. Pumpkin wants to know how much fertilizer to use on her roses for best growth. She divides her rose garden into three sections. She fertilizes section A once per year, section B twice per year and section C three times per year. Independent Variable – number of fertilizations Dependent Variable – growth of roses

DESIGNING AN EXPERIMENT CONT. II. CONTROL GROUP: All conditions are kept constant

Hmm… In the following experiment, identify the control group, experimental group, and the independent and dependent variables. John is studying the effect of a new fever reducing drug. He administers 50 mg of the drug to 100 patients in Group I and 75 mg to 100 patients in Group II. Group III does not receive the drug.

Hmm… In the following experiment, identify the control group, experimental group, and the independent and dependent variables. John is studying the effect of a new fever reducing drug. He administers 50 mg of the drug to 100 patients in Group I and 75 mg to 100 patients in Group II. Group III does not receive the drug. Control Group – III Experimental Group – I, II Independent Variable – mg of drug Dependent Variable – reduction of fever

OTHER CHARACTERISTICS OF GOOD EXPERIMENTS: Title (The effect of…on…) Testable hypothesis (If… then…, include #s) Constants (conditions that stay the same for all experimental groups) Detailed, repeatable procedure Lots of repeated trials

Write one paragraph the summarizes the main points for this lesson. Your paragraph should have an introductory and conclusion sentence. You should write a minimum of 5 sentences. Notes Summary Have a great semester!