The Scientific Method Reading Graphs A B C

The Scientific Method & Reading Graphs A. B. C. D. E. Define basic terms associated with science Define the scientific method List & describe the steps of the scientific method Identify variables, constants, and controls in an experiment Construct, label, and discern different types of graphs

A. Define basic terms associated with science Science n. A process through which nature is studied, discovered, and understood.

A. Define basic terms associated with science Theory n The most probable EXPLANATION based on the best available EVIDENCE.

A. Define basic terms associated with science Facts n Facts -- Data or EVIDENCE that can be OBSERVED repeatedly

A. Define basic terms associated with science Hypothesis n An EDUCATED guess n A TESTABLE statement

B. Define the scientific method What is the Scientific Method? n An orderly approach to answering questions and solving problems.

C. List & describe the steps of the scientific method Steps to the Scientific Method #1 Identify Problem #2 Research It! #3 (ask a question) Make a Hypothesis Test It #4 #5 Try Again! Analyze Results It’s TRUE! It’s FALSE

C. List & describe the steps of the scientific method Step #1: The Problem n n States the purpose of doing an experiment. MUST be stated as a question Examples: -Which type of fertilizer will promote the most growth in poinsettias? -What type of feed will make my hog gain 3 pounds per day to make weight for the fair? -Which type of welding electrode will make the best looking weld bead?

C. List & describe the steps of the scientific method Step #2 Research n n Read and study what is ALREADY KNOWN about the topic Get advice from others

C. List & describe the steps of the scientific method Step #3: The Hypothesis n n n An EDUCATED guess Answers the question in the problem Written in “If, then” form Examples: -If I use 20 -10 -20 Fertilizer, then the poinsettias will grow the fastest -If I use Purina Show chow, then my hog will gain at least 2 pounds per day -If I use 6011 rod, then the weld will look best.

C. List & describe the steps of the scientific method Step #4: Perform Experiment n n Carry out the experiment Keep records of results

C. List & describe the steps of the scientific method Step #5: Analyze Results n Determine the truth of your hypothesis based on your results

D. Identify variables, constants, and controls in an experiment Variables n Independent variable (IV) - the variable that is CHANGED – (what is being tested) n Dependent variable (DV) - the variable that RESPONDS and is MEASURED.

D. Identify variables, constants, and controls in an experiment n Control- the item being tested with NO CHANGES – used to compare n Constant (C) - all factors that are kept the same during the experiment.

The Purina Feed salesman visits you and claims that his hog feed will cause your hogs to have a higher ADG (average daily gain). So, you design an experiment to see if he is correct. You get two pens with 10 hogs each. The hogs are all within 10 pounds of each other. You feed your current feed to one pen and the Purina feed to the other pen. At the end of 30 days, you weigh each pig and calculate the ADG for each pen. n n n n Problem: (question) Hypothesis: If/Then Experiment: How will you test it IV: What changes Trials: How many times will you test it DV: The variable that responds C's: What does NOT change Conclusion: Results of Test

n n n Problem: (question) Which hog feed will cause my hog to gain the most weight? Hypothesis: (If/Then) If I feed Purina Show Chow to my hog, then it will gain the maximum weight each day. Experiment: (How will you test it) – IV: Type of Feed n – Trials: (how many times will you repeat the experiment) 10 times – DV: (what responds) Weight – C's: (what doesn’t change) Environment, original weight/age of pigs Conclusion: (Results of Test) Hogs eating Purina Show Chow had the highest ADG (average daily gain)

Example #2 n The salesman at the Honda dealership claims the Honda Civic gets much better gas mileage than the Toyota Camry. You decide to design an experiment to see if he is correct. You get a brand new Civic and a brand new Camry. Both of the cars are comparable in the features that each one has. You determine the gas mileage three times each. Each car was driven the same place and way while determining the mileage. n Problem: Which car gets better gas mileage? Hypothesis: If I compare the Civic and the Camry, then the Civic will get better gas mileage. Experiment: Drive both vehicles the same distance, over the same roads and measure gas mileage. IV: Type of Car (Civic vs Camry) Trials: Repeat 3 times DV: gas consumption C's: Miles traveled Conclusion: The Honda Civic gets better gas mileage n n n n

E. Construct, label, and discern different types of graphs Why use graphs & tables in science? ? n n To arrange data (numbers) so they are easy to compare Makes numbers VISUAL!

E. Construct, label, and discern different types of graphs Types of Graphs n Line Graphs – 2 variables – lots of #’s

E. Construct, label, and discern different types of graphs Types of Graphs n Bar Graphs – Easy to compare results – Easy to see an average

E. Construct, label, and discern different types of graphs Types of Graphs n Pie Charts – Data usually equals 100%

Line Graph Data Chirping Rates of Crickets at Different Temperatures Temperature Juvenile crickets Adult Crickets 45 degrees F 48 Chirps/minute 32 Chirps/minute 60 degrees F 72 Chirps/minute 56 Chirps/minute 75 degrees F 96 Chirps/minute 73 Chirps/minute 90 degrees F 107 Chirps/minute 98 Chirps/minute

Bar Graph Data Number of biology Students by Period # of Students 1 st Period 25 2 nd Period 33 3 rd Period 29 4 th Period 27 5 th Period 32 6 th Period 27 7 th Period 21

Study for the quiz… n n Definitions Find DV, IV, Hypothesis, Problem, constant, trials of an experiment

Bell Quiz n n n 1. Give an example of a hypothesis 2. What is an independent variable? 3. What is a dependent variable? 4. What is a constant? Why do you need a constant in an experiment? 5. What is a control? Why do you need a control in an experiment?

Bell Quiz n Study for the quiz on Scientific Method – Make sure you can identify the IV, DV, Constant, Hypothesis, etc!