What is Science? Science: Process that produces information about nature Steps: Observation & Experimentation Why: Apply the results to the real world Why: Better understand our world Information gathered by the “Scientific Method”

Defined: Series of steps to collect information or solve problems 1) Observation 2) Hypothesis 3) Experimentation 4) Data Analysis 5) Conclusion Scientific Method

Observation and Hypothesis 1 st step: Make an observation –Example: Why is there little ground vegetation in this forest? 2 nd step: Create a hypothesis –If…then statement –Example: If there are tall trees blocking sunlight, then few plants will grow near the ground.

3 rd step: Design an Experiment Experiments test the independent variable Independent variable: factor altered Two parts to an experiment 1)Control group: comparison group Ex: patch of forest with the large trees 2) Experimental group: contains the independent variable Ex: patch of land w/o canopy trees Data collected is called the dependent variable Ex: growth height of the plants

Here is a well designed setup

Control GroupExperimental Group 6 hours sun/day 8cm rain/month Grazing animals 60 ⁰ temp Large canopy treesPatch of open land The experimental plants grew 1 meter taller. What most likely caused this change?

Here is a poorly designed setup

Control GroupExperimental Group 6 hours sun/day 4 hours sun/day 8cm rain/month Grazing animals 60 ⁰ temp 80 ⁰ temp Large canopy treesPatch of open land The experimental plants grew 1 meter taller. What most likely caused this change? Unknown! Too many changed variables!

4 th Step: Data Analysis Collect data to either support/reject your hypothesis –Ex: Plants on the ground grew almost 1m taller w/o the canopy trees –No hypothesis is proven after 1 experiment

5 th Step: Conclusion Your findings could be shared and repeated by others Theory develops over time –Theory = long standing hypothesis Theories and hypotheses change based on new information

Farmer Bob wants to test a new fertilizer to help his crops grow better. He sections off two large areas of his field. In section A, he waters his crops as usual and uses his normal fertilizer. In section B, he waters his crops as usual and but adds the experimental fertilizer. After 1 growing season, he records the growth of the crops. Name the control group _________________________________________________ Name the experimental group ____________________________________________ Name the independent variable __________________________________________ Name the dependent variable ____________________________________________ Section A Section B Type of fertilizer used Growth of the crops

The United States military wants to see if soldiers with only 4 hours of sleep can operate at the same level as those who normally get 7 hours of sleep. One hundred solders are allowed to only sleep for 4 hours a night and another hundred are allowed to sleep for 7 hours a night. During the day, the soldiers are tested for marksmanship on the firing range. Name the control group _________________________________________________ Name the experimental group ____________________________________________ Name the independent variable __________________________________________ Name the dependent variable ____________________________________________ Soldiers with 7 hours sleep Soldiers with 4 hours sleep Amount of sleep given Score on the firing range

A teacher wants to know if her new teaching method is more successful than traditional teaching methods. She compares test scores of her period 2 class (received the traditional teaching method) verses her period 4 class (received new teaching method). Each class has a random mix of honors students. Name the control group _________________________________________________ Name the experimental group ____________________________________________ Name the independent variable __________________________________________ Name the dependent variable ____________________________________________ Period 2 students Period 4 students Teaching method Test scores

A high school soccer team on average scores 2.2 goals per game by practicing 4 days a week. The coach wants to see if practicing 5 days a week will help the team score more goals. The coach has the team practice 5 days per week and compares the goals scored per game. Name the control group _________________________________________________ Name the experimental group ____________________________________________ Name the independent variable __________________________________________ Name the dependent variable ____________________________________________ Practicing 4 days per week Practicing 5 days per week Length of practice Goals scored per game

The city of Los Angeles wants to know if there is a connection between physical fitness and air pollution. Fifty volunteers from the mayor’s office agree to be tested. First, they are asked to ride a stationary bike for 1 hour in a pollution-free air chamber. A week later, the 50 volunteers return and are again asked to ride a stationary bike for 1 hour in a chamber filled with air pollutants common to Los Angeles. Their heart rates are monitored throughout the 1 hour bike rides. Name the control group _________________________________________________ Name the experimental group ____________________________________________ Name the independent variable __________________________________________ Name the dependent variable ____________________________________________ Volunteers who breathed common polluted air Volunteers who breathed clean air Quality of air breathed Heart rates