Scientific Method

What is Science?

Science is a process.

Science often starts

with a question.

What is Science?

Science – a process of gathering knowledge about the natural world.

Questions

After you ask a question, you look for an answer. What are some methods you use to answer a question?

• Research

• Observations

• Experimentation

Why ask questions? Give an example for each

reason.

• Save lives - how can people be protected during car accident = seatbelts and airbags

• Save resources - how can resources last longer = recycle,

• Save environment - how can ozone be protected = reduce CFC use

A common misperception of science is that science defines "truth".  Science does not define truth, but rather it defines a way of thought.  The scientific method is a process in which experiments are used to answer questions. 

Question

Research

An “educated” guess of an answer to a question.

Written and carefully followed step-by-step experiment designed to test the hypothesis.

Information collected during the experiment.

Written description of what was noticed during the experiment.

Conclusion

Data

Experiment

I. Scientists use an experiment to search for cause and effect relationships in nature. In other words, they design an experiment so that changes to one item cause something else to vary in a predictable way.

Experiment

II. These changing quantities are called variables. A variable is any factor, trait, or condition that can exist in differing amounts or types. An experiment usually has three kinds of variables: independent, dependent, and constants.

Variables

1. Independent The independent variable is the one that is changed by the scientist.

2. Dependent The scientist focuses his or her observations on the dependent variable to see how it responds to the change made to the independent variable.

Trials

Dis

tanc

e in

cm

Independent D

epen

den

t

Variables

3. Experiments also have constant variables. Constants: are quantities that a scientist wants to remain the same, and he must observe them as carefully as the dependent variables.

Dep

end

ent

Independent

Operational Definitions:

A conceptual definition is an element of the scientific research process, in which a specific concept is defined as a measurable occurrence. It basically gives you the meaning of the concept.

Operational Definitions:

Following the establishment of a conceptual definition, the researcher must use an operational definition to indicate how the abstract concept will be measured.

For example define melt:When an object changes its physical shape from a solid to a liquid.