Chapter 1 Section 2 The Scientific Method

What Are Scientific Methods? Observations lead to questions or problems. Scientific methods are steps used to answer the question/solve the problem. The steps can be used in or out of order.

Getting Started It all begins with a question. Make observations: Take pictures Measure Write a description Collect data Test and record Use appropriate tools.

Form a Hypothesis Questions + observations can lead to a: hypothesis. Hypothesis: a possible answer/explanation of the question. Based on observations. Can be tested. Logical, creative, builds on prior knowledge.

Activity: What happened to the Flask? Using the Erlenmeyer flask cutouts, you will: Color some liquid “chemical” into the flasks. Cut out the flasks and glue them apart from each other near the top of page 46. Write out the following prompt right beneath the flasks: “You only left the lab for 15 minutes to grab a snack. When you came back, the flask you just filled was broken at the top, with some chemical spilled. Propose 3 different hypotheses as to how/why the flask broke in your absence (or what caused it to break).” Remember to keep in mind what makes a good hypothesis.

“When there is less oxygen in the water, rainbow trout suffer more lice.” “Ladybugs are a good natural pesticide for treating aphid infected plants.” “Aphid-infected plants that are exposed to ladybugs will have fewer aphids after a week than aphid-infected plants which are left untreated.” “Our universe is surrounded by another, larger universe, with which we can have absolutely no contact.”

Homer was told that a certain itching powder was the newest best thing on the market. It even claims to decrease itching by 50% because it contains caffeine. Interested in this product, he buys the itching powder and compares it to his usual product, which contains aloe vera. On one itching spot, he puts the new powder. On another itching spot, he puts his old cream. He then times how long it takes for the products to stop his itch.

Let’s Review The first 3 steps of the Scientific Method are: Question Observation Hypothesis

Before The Hypothesis Predictions must be made before the test. Prediction: a statement of cause and effect (if-then). More than one prediction can be made. Experiments are done to test predictions and hypothesis. Experiments can match or not.

Testing the Hypothesis An experiment tests the hypothesis. Different factors can influence an experiment. A controlled experiment tests one factor at a time. A factor that differs from the others is the variable.

Designing an Experiment Every factor must be considered. Ethics and proper guidelines must be in place. Safety is the top priority and common sense is essential.

Activity: Simpson Science Part 1: Venn Diagram Compare predictions and hypotheses. Write 3 to 4 pieces of information for each part. Include at least one graphic. Cut out and glue tab onto the top of page 52 Part 2: Simpson Scenario Read the scenario and complete the steps. Glue near the bottom of page 52.

An experiment is conducted to determine the effects of energy drinks on an individual’s heart rate. Groups A and B have been matched for all factors such as age and sex. Each person in group A is given two ‘Red Bull’ energy drinks for breakfast and lunch, and then the heart rate is measured. Each person in group B is given water to drink with breakfast and lunch, and then their heart rate is measured. Both groups are fed the same breakfast and lunch. The results are recorded.

Analyzing the Results An experiment produces data that must be analyzed. With analysis comes the need for organization. Analysis allows for the variable to be explained.

Draw Conclusions Do the results match the hypothesis? Did I reach the answer I expected? Were there any mistakes? Do I need to make any revisions, or repeat any steps?

Communicate the Results When all is said and done, communicate the results. Information is shared, revealed, or published. Other scientists are informed and can compare notes. The results can influence other scientists and experiments.

Activity: Scientific Method Four Square (56) Choose a question/problem from the list. Write the question and provide a graphic in square 1. Create a hypothesis and provide a graphic in square 2. Design an experiment to test your hypothesis and provide a graphic in square 3. Explain how you would communicate your results and provide a graphic in square 4.

Hyperactivity is unrelated to eating sugar. If you drop a ball, it will fall toward the ground.

Students saw advertisements for two brands of light bulbs: Costs $.50 less than other brands! Lasts 30 hours longer than other brands! The students are unsure how to decide which brand of light bulb is the better buy. Describe two additional pieces of information that would help the students decide which bulb is the better buy. Design a quick experiment to test which bulb would actually be the better buy.

A team of scientists wants to study the size of Anaconda snakes in the wild. After capturing a snake, the team measures and records the length of each snake. After the snakes are released, the team finds the average length of the snakes they captured. 1. Which parts of the scientific method have the scientists used? 2. Which part of the scientific method should the scientists move on to next?

Vocab Cards Protocol Cut cards in half. {Glue this onto the top of page 15} Cut cards in half. Write term on front and draw a picture to illustrate term as you can remember it. Use the term in a sentence on back of card. Tape the card onto the appropriate page in journal. Write the definition behind the card on the notebook side.

Vocabulary Scientific method Hypothesis Controlled experiment Control group: a group of subjects not being experimented upon and used for comparison. Independent variable: a variable that stands alone and will not change after the experiment. Dependent variable: a variable that can/will change after the experiment. The terms above are not found directly in your textbook. Please rewrite the definitions above in your own words. Scientific method Hypothesis Controlled experiment Prediction The terms above can be found on pages 12-16.

Continue Vocabulary Scientific method Hypothesis Controlled experiment Control group: a group of subjects not being experimented upon and used for comparison. Independent variable: a variable that stands alone and will not change after the experiment. Dependent variable: a variable that can/will change after the experiment. The terms above are not found directly in your textbook. Please rewrite the definitions above in your own words. Scientific method Hypothesis Controlled experiment Prediction The terms above can be found on pages 12-16.

Independent vs. Dependent Independent example: someone's age might be an independent variable. Other factors (such as what they eat, how much they go to school, how much television they watch) aren't going to change a person's age. Dependent example: a test score could be a dependent variable because it could change depending on several factors such as how much you studied, how much sleep you got the night before you took the test, or even how hungry you were when you took it.