Warm-up: 8 minutes Just write your answers in complete sentences. You may use your notes. There is no talking. 1.Dr. Cao was walking in the park one day when she sees a dog with three legs. a)What is the observation that she made? b)What inference can be made? 2.What is the formula for density? 3.M = 2000 g, V = 10 ml. What is density? Don’t forget the units!

The Scientific Method

An organized way to solve a problem through experimentation & observation. This is the basis of science!

The 6 Steps of the Scientific Method

1. State the Problem Form a question or observation about a specific event Example: Mouthwash kills bacteria. Which brand works best?

2. Form a hypothesis and predictions A hypothesis is an educated guess that explains your observation or problem. You will then form predictions, which are expectations based on your hypothesis. Example: IF Listerine has more antiseptic ingredients than Crest or the Wal-Mart brand, THEN it will kill more bacteria.

2. Form a hypothesis and predictions Example Hypothesis: Name brand mouthwash works better than store brand. Example Predictions: If name brand mouthwash works better, then Listerine should kill more mouth bacteria than the Wal-mart brand

3. Design an Experiment Create a way to test your hypothesis. Create aCONTROLLEDexperiment.

A controlled experiment MUST have 2 groups. CONTROL GROUP: all conditions remain the SAME! It is a group you do not do anything to. EXPERIMENTAL GROUP: a group or many groups who you test. The experiment is performed on this group.

Establish the variables for your experiment. INDEPENDENT VARIABLE: the variable that you change or manipulate (X axis for graphing) DEPENDENT VARIABLE: the change or result that happens when the independent variable is used (Y axis for graphing)

Establish the variables for your experiment. INDEPENDENT VARIABLE: the variable that you change or manipulate (X axis for graphing) DEPENDENT VARIABLE: the change or result that happens when the independent variable is used (Y axis for graphing)

4. Conduct your experiment and collect data

Mouthwash Experiment Petri dish Bacteria grown from swab Control Group -no mouthwash Experimental Group Listerine Crest Brand Wal-Mart brand

Mouthwash Experiment INDEPENDENT VARIABLE: DEPENDENT VARIABLE: Type of Mouthwash Amount of bacteria killed

Recording data Mouthwash brand ListerineWal-mart brand Control- no mouthwash Number of bacteria

5. Analyze Data Describe your data

2 Types of Data QUANTITATIVE: numerical data, deals with specific quantities, usually in the form of a graph or chart QUALITATIVE: descriptive data, describes how something looks, smells, sounds, or feels; deals with qualities

QUALITATIVE EX: The control group and the Wal-Mart brand have a strong smell; the Listerine & Scope don’t smell as bad. QUANITATIVE EX: Area of Inhibition for Mouthwash Brands ControlListerineScopeWal-Mart 5 min0 mm3 mm2 mm1 mm 10 min0 mm4 mm3 mm 15 min0 mm6 mm5 mm4 mm 20 min0 mm8 mm6 mm4 mm

6. Form Conclusions Determine from the data collected if the hypothesis was correct or incorrect Do this by comparing results to predictions

EX: You predicted Listerine would kill more bacteria than Wal-mart. But your data show that both Listerine and Wal-mart brand killed the same amount of bacteria. Was your hypothesis supported? Your hypothesis was that brand name mouthwash was more effective at killing bacteria than Wal-mart brand.

Let’s Practice Who has a problem that they think science can help us solve?

Exit Ticket I have 2 pairs of shoes and I am not sure which pair of shoes will make me run faster. How do I find out? What should I do? Use the 6 steps of the Scientific Method in your answer.

Class Experiment You will be designing an experiment to help you to better understand the scientific method. Break up into groups (of 2-3 members) and design an experiment to investigate any testable hypothesis. Choose only one variable to manipulate. You will must work through all of the steps of the scientific method: –ask a question –develop a hypothesis and predictions –design your experiment (list materials that you will use, and outline your procedure in detail, determine what data you will collect) –pretend that you conducted your experiment and collected data –analyze your data –form a conclusion (was your hypothesis supported or not? Compare your results to predictions.).