Chapter 1, Section 2 StandardInvestigation and Experimentation. Scientific progress is made by asking meaningful questions and conducting careful investigations. Objective 1Identify the steps that make up scientific methods. Objective 2Analyze how scientific thought changes as new information is collected. AssessmentMythbusters Activity, Chapter Test ReviewDaily Bellwork, Science Starters

Key Terms Create a flash card for the following key terms (p. 9 in textbook):  Observation  Hypothesis  Independent variable  Dependent variable  Theory If you finish early, study your flash cards!

The Scientific Method

Ask a Question The Scientific Method begins with observations based on sight, touch, taste, hearing, or smell. These observations often lead to a question. For example after seeing a tornado one might ask, “What causes a tornado to form?” or after being in an earthquake one might ask, “Why did my books fall off the shelf but the CDs did not?”

Form a Hypothesis Once a question has been asked and observations have been made, a HYPOTHESIS is made. A HYPOTHESIS is a possible solution or answer to the question; an educated guess. For example: I might hypothesize that houseplants in the sun will grow faster than plants in a location without sun.

INTERACTIVE Write a hypothesis for the experiment below: ◦ A scientist is going to measure toy car speed on a ramp. He is going to test if the size of the wheel affects the speed of the toy car going down a ramp. He has a regular toy car, a toy car with extra large wheels, and a toy car with mini-wheels. ◦ What is your hypothesis??

Test the Hypothesis Once a question has been asked and a hypothesis made it is time to develop an experiment to test the hypothesis! Factors that can be changed in an experiment are called VARIABLES. INDEPENDENT VARIABLE= a factor that can be changed by the person conducting the experiment. DEPENDENT VARIABLE= the factors that change as a result of changing the independent variable.

INTERACTIVE In the toy car experiment fill in the following: ◦ Independent Variable______________ ◦ Dependent Variable_______________

Models In Earth Science it is often impossible to use a controlled experiment. When experiments can’t be done Scientists observe evidence and make observations. Scientists also use MODELS such as maps, 3-D miniatures (of mountains, solar objects, etx), Computer models.

Quick Check! 1. Name the 1 st step of the Scientific Method. ___________________ 2. Name the 2 nd step of the Scientific Method. ___________________ 3. The variable that the person doing the experiment can change is called the ______________ variable. 4. The variable that changes as a result of the experiment is called the _________ variable.

Example To test which plants grow faster some plants are placed in direct sunlight, others in the dark. The Independent Variable is the sunlight, the Dependent Variable is the growth of the plants.

Read about the Experiment below and answer the questions in your notes… One day 3 students were working on their science fair project. They were conducting an experiment to see if the amount of time spent studying affected the test score. They each studied with the same materials, for the same test. Student A studied for 20 minutes, Student B studied for 1 hour, and Student C studied for 2 hours. They each took the same test, at the same time and then compared their results: Student A=64% Student B=85% Student C=97% In the experiment above, give a possible Hypothesis: ____________________________________________ What is the Independent Variable? ____________________ What is the Dependent Variable?______________________

Variables It is very important that in any experiment only ONE VARIABLE should be tested. In the previous experiment on studying, only the time was changed. What would happen to the results if the time was changed for each person, but also they each studied for a different subject??

The Scientific Method—What’s Missing??

Draw Conclusions After the experiment is complete it is time to draw conclusions! Was the hypothesis correct?? Was it wrong? The results may lead to more questions, in which case a new experiment may be developed.

The Scientific Method—What’s Missing??

Interactive! Create a Haiku about the Scientific Method. You may work with your group, but everyone must write the Haiku in their notebooks. 3 lines: ◦ 5 syllables in first line ◦ 7 syllables in second line ◦ 5 syllables in 3 rd line Example: Observations and Experiments are a part Of the good method

Animated Scientific Method

Measurements Throughout the Scientific Methods scientists need a common system of measurement so they can share information: International System of Units or SI

Brain Pop-Scientific Method

Acceptance of Ideas Once an experiment is complete and conclusions have been drawn the experiment is often repeated by other scientists. When the hypothesis is confirmed repeatedly and undergone a LOT of testing, it will form a THEORY. A THEORY is an explanation/answer for a scientific question.

Hypothesis vs. Theory Hypothesis Educated guess Not tested yet or Not tested much Theory Well-accepted answer Well-tested Supported by many experiments

Interactive! Quickwrite: In your own words explain the difference between Hypothesis and Theory.

Error No experiment is perfect. Many things can go wrong and many things cannot be controlled. Scientists acknowledge that there will be error. Scientists ALWAYS identify and communicate sources for error.

Sources for Error… Human Error Instrument Error Environmental Materials not uniform

Quick Check! 1. What is the difference between a hypothesis and a theory? __________________________________ __________________________________ ______________________ 2. Name 2 sources for error in experiments? __________________________________ __________________________ 3. What is the last step of the Scientific Method? __________________________________ __________________________________ __________________________________ ___

INTERACTIVE In your own words, summarize what you have learned about the scientific method and sources of error. At LEAST 6 sentences.

Assessment Mythbusters Episode: Identifying the Steps of the Scientific Method and possible sources of Error! 1. Watch the episode of Mythbusters. 2. While watching, fill in the steps of the Scientific Method and the possible sources of error. 3. Create a Mini-Board