Scientific Method A way to understand CAUSE AND EFFECT in the natural world

Scientific Method Step 1: OBSERVE Step 2: FORM A HYPOTHESIS Step 4: COLLECT DATA Step 3: DESIGN AN EXPERIMENT Step 5: MAKE CONLCUSIONS Step 6: COMMUNICATE FINDINGS

Scientific Method: Step 1 - Observation Based on your 5 SENSES  Seeing  Hearing  Smelling  Touching  Tasting

Scientific Method: Step 2 –Form A Hypothesis Must be “testable” If, independent variable is changed by you Then - predict how dependent variable will respond ‘If-then statement’

Scientific Method: Step 3 – Design an Experiment Need to include 2 different variables: Independent Variable: The variable that is deliberately changed in the experiment. Dependent Variable: The variable that is observed and may change in response to the manipulated (independent) variable. Need a Control: Factor in the experiment that is purposefully kept the same the entire time. Used to compare other results against. Experiment is based on your hypothesis.

Scientific Method: Step 4 : Collect Data & Analyze Data can be Qualitative (descriptive observations…using your senses) Ex: The plant is green. Or Quantitative (actual #’s/measurements are used) Ex: The plant is 4 inches tall.

Scientific Method: Step 4 –Data Collection + Analysis TABLES GRAPHS

Scientific Method: Step 5 – Conclusion and Discussion Do your results support your hypothesis?  State why or why not?  Analysis of your data  Did you run repeat trials?  Identify sources of errors  Identify changes you would make

Step 6: Communicate Findings Always share your findings with other members of your group or class to confirm your results or come up with new questions to test.

Let’s Practice… Background: Red Bull ads claim to increase concentration Ques: Can Drinking Red Bull before a test improve performance ? Identify variables (anything that changes) Number of red bull drinks and performance on test Independent variable and dependent variable

Scientific Method Practice Forming the Hypothesis -If red bull drink is consumed 15 minutes before the test then, average test score of students in a Biology class will increase by 5% or more - ‘If-then hypothesis statement’ 1. If independent variable is changed by you 2. then - predict how dependent variable will respond

Scientific Method: Step 3 – Planning the Experiment Experimental Design : A.Variables – anything that can change in an experiment - Independent Variable: anything that you change/manipulate in an experiment (red bull energy drink) - Dependent Variable: anything that you measure as the ‘response’ to the change you made (average test score) - Controlled Variables: anything that you would keep the same in all experimental setups - such as time when drink was consumed, other types of stimulants the student has, test environment….

Scientific Method: Step 3 – Planning the Experiment Control group/setup: does not have the independent variable Experimental setup: has the independent variable Group with red bull Group without red bull