Scientific Method

• A way to understand CAUSE AND EFFECT in the natural world

Scientific Method

Step 1: OBSERVEStep 2: FORM A HYPOTHESIS

Step 4: COLLECT DATAStep 3: DESIGN AN EXPERIMENT

Step 5: MAKE CONLCUSIONSStep 6: COMMUNICATE FINDINGS

Scientific Method: Step 1 - Observation

• Based on your 5 SENSES

SeeingHearingSmellingTouchingTasting

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 dataDid you run repeat trials?Identify sources of errorsIdentify 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 PracticeForming 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