Understanding the Scientific Method What is Science? A method of studying the natural world through observation and investigation.

What is science? Science is the means by which we explain and understand nature. Nature comprises the natural world, from the inner workings of our bodies to the behaviors of animals. It’s all science!

Science is learned by Doing INVESTIGATIONS You must DO science in order to learn it. -observation, experiments, models

Scientific Method Science investigations must follow a set of steps called the scientific method. State the problem- Why? Purpose? Gather information Form a Hypothesis – educated guess Test the Hypothesis - experiments Analyze the Data- Draw Conclusions-

Experiments – Testing hypothesis Experiment – tests the effect of one thing on another using controlled conditions. variable – a quantity that can have more than a single value. 1. dependent variable – its value changes (depends) according to the changes in the other variable. 2. independent variable – the variable you change to see how it will affect the dependent variable.

Constant – a factor that does not change when other variables change Constant – a factor that does not change when other variables change . control – a standard by which the test results can be compared. Examples:

Independent variable is manipulated Dependent variable is observed and measured Control variables are other factors in the experiment that are kept constant or the same

A GOOD Scientific Experiment: One variable changed at a time; everything else remained constant or controlled Repeated trials to eliminate error Organized and analyzed properly

For us: Lab Investigations/ Reports Purpose – Background – Hypothesis – Materials - Procedures - Data - Analysis – Conclusions – (Problem) (Gather info) (hypothesis) (Test hypothesis) (analyze data) (draw conclusions) ALL MUST BE INCLUDED IN A LAB REPORT

Purpose Why did you perform the lab investigation? -For your benefit, so that you will understand what the goal of the lab is.

Background Helps us view a fuller picture of what is being investigated. Sometimes detailed Sometimes brief Summarize

*****BE SPECIFIC***** Hypothesis For us, keep it simple an if/ then statement Examples: “If we touch the smoke then something will happen.” OR “If we add these chemicals then something will happen.” NOT ACCEPTABLE!!! *****BE SPECIFIC*****

Hypothesis State what you will do and what you think will happen. “If the Nitric acid causes a chemical reaction with the copper in the penny, then the penny will be dissolved.” ACCEPTABLE!

Materials What will you need to test your hypothesis? Be thorough!

Procedures What steps will you have to do to test hypothesis?

Results Data Collected during the lab. (tables and graphs, etc) Analysis What was the end product of your lab? Trends or anomalies? Sometimes there will be questions to help you THINK!

Conclusions Did you support or refute the Hypothesis? What chemistry or physics did you observe. What concepts did the lab illustrate or help you learn? This is where you should pull it all together. This is the part where teachers are looking to see if you really understood.

Theory or Law? Theory – a judgment based on the results of an experiment. Ex. Theory of evolution Law – something that has been proven to be true. Ex. Law of gravity