Introduction to Science and the Scientific Method Science 8

What is Science? The goal of science is to investigate, understand, explain events, make connections about the natural world. In elementary school, what did you learn about in science? List two things: _________________________________________ ____________________________________________

How is Science done? Science always begins with an initial observation Can you think about three observations that you have made so far throughout the day. Share your observations with a friend.

How is Science done? What usually follows after an observation? Ask a Question Can you think of an example? _____________________________

Scientific Method The scientific method is a series of steps used by a scientist to solve a problem or answer a questions The steps include: Make an Observation Ask a Question Make a Prediction (aka Forming a Hypothesis) Plan and Conduct a Controlled Experiment Process and Analyze Data Evaluate and draw Conclusions (you often need to repeat experiments multiple times) Communicate results Apply and Innovate

Make a Prediction (aka Hypothesis) A hypothesis is a scientific explanation to the question you had on the observations you have made You are making a prediction You have to be able to test your hypothesis Your hypothesis hasn’t been proven correct or incorrect yet.

Hypothesis We like to use “if……..then…….” statements Example: If you drink coffee before going to bed, then it will take longer to fall asleep. If you cover a wound with a bandage, then it will heal with less scarring. Can you think of one? __________________________________________ __________________________________________

Plan and Conduct a Controlled Experiment In an experiment, there are many factors that affect the results of an experiment Theses factors are called variables Some examples of variables include: changing the temperature, the amount of light, time, concentration of solutions A controlled experiment works with one variable at a time In a controlled experiment, only one variable is changed at a time. All other variables should remain the same.

Plan and Conduct a Controlled Experiment Variables that changes in an experiment are called independent (manipulated) variables The results due to the independent variable is called the dependent (responding) variable

Plan and Conduct a Controlled Experiment An experiment is based on the comparison between a control group with an experimental group These 2 groups are identical except for one factor The control group serves as the comparison. It is the same as the experimental group, except that the one variable that is being tested is removed The experimental group shows the effect of the variable that is being tested

Plan and Conduct a Controlled Experiment Example: Larry was told that a certain muscle cream was the newest best thing on the market and claims to double a person’s muscle power when used as part of a muscle-building workout. Interested in this product, he buys the special muscle cream and recruits Patrick and SpongeBob to help him with an experiment. Larry develops a special marshmallow weight-lifting program for Patrick and SpongeBob. He meets with them once every day for a period of 2 weeks and keeps track of their results. Before each session Patrick’s arms are lathered in the muscle cream, while Sponge Bob’s arms are lathered with the regular lotion. The size of their arms are measured. Time Patrick (cm) SpongeBob (cm) Initial Amount 18 5 After 1 Week 24 9 After 2 Weeks 33 17

Plan and Conduct a Controlled Experiment Which person is in the control group? Which person is in the experimental group? What is the independent variable? What is the dependent variable?

Process and Analyze Data Observations from the experiment can be recorded down as data. The data that has been collected must be organized and analyzed You want to know if the data support or not support the hypothesis

There are 2 types of data: Quantitative Data are: numbers and are obtained by counting and measuring Qualitative Data are: descriptions and involve characteristics that cannot be counted

EXAMPLES OF QUANTITATIVE DATA EXAMPLES OF QUALITATIVE DATA

Evaluate and Draw Conclusions The evidence from the experiment is used to determine if the hypothesis is proven correct or proven incorrect Experiments must be repeated over and over. When repeated, the results should always be the same before a valid conclusion can be reached.

Communicate Once a valid conclusion has been reached, results can be communicated to the scientific community. With more time and further investigation, theories and laws can be developed. This information can be shared with the general public and to students like you!

Apply and Innovate When scientists draw valid conclusions in experiments, it will often leads to application of real life situations. Example: Math and Physics calculations involved in building a bridge Example: The discovery of genes in plants to treat diseases in animals Experimental conclusions often lead to other scientists wanting to innovate new ideas and experiments. Scientists build and learn from one another Scientists communicate with one another Scientists depend on one another The success of scientific discoveries depends on this.