The Scientific Method

Why do we have the scientific method? Gives us logical steps to follow to assist us in answering a question.

What are the steps? Develop a question Conduct background research Form a hypothesis Test with an experiment Make observations and collect data Analyze the results Draw conclusions Report results and test again

Parts of an experiment

Independent Variable Part of the experiment that the scientist changes What is being tested There is only one independent variable at a time. What I change

Dependent Variable Part of the experiment that changes because of the independent variable

Part of the experiment that does not receive the independent variable Control Part of the experiment that does not receive the independent variable

Constants Part of the experiment that remain the same for every part of the experiment

Types of Data Quantitative Data that is numerical in nature Qualitative Data that is descriptive in nature

On a note card, describe your lab partner using 3 quantitative and 3 qualitative observations Also put the person’s name you are describing on the card.

An example experiment A person wants to test whether music can help make plants grow. The person plants several seeds from the same batch into identical flower pots with identical potting soil, watering schedule and light supply. One flower pot is isolated from the sound supply, while the other pots are subjected to various types of music. After 1 month, the “healthiness” of each plant is measured.

Experiments Don’t Always Go According to Plan Accidental Discoveries Teflon Mauve clothing dye

Theories and Laws When a hypothesis withstands repeated testing, it may become a theory – a well-tested explanation of observations Theories are explanations, not facts They can be disproved, but can never be completely proven. Law is a statement or mathematical expression that reliably describes a behavior in the natural world

The main difference While a theory is an attempt to explain the cause of certain events in the natural world, a scientific law describes the events

Models A model is a representation of an object, a system, a process, or an idea. A model is used to help describe or communicate information about ideas or theories that are difficult to observe or explain otherwise.