Scientific Method

Experimental Design

It all starts with a question!

• Who, what, when, where, why?

• Scientists work to answer questions.

• The need to find answers drives technology.

• New technology leads to new discoveries and more questions.

Research/Data Collection

• The longest (on going) phase of scientific investigation. Data = any and all information scientists gather in trying to answer their questions.

• The next step is to gather information.

• What do we know? We have to be informed before we can make an……..

Data Collection

• Data is collected through OBSERVATION.

• 5 senses – exactly what is felt, seen, heard, smelled, or tasted.

• Inference= interpretation of observation.

• Described 1 of 2 ways:

• Quantitative = Numbers ex: 43 inches

• Qualitative = Words ex: blue, gritty

HYPOTHESIS

• Statement that explains the observations and can be tested.

• Testable only if evidence can be collected that either does or does NOT support it.

• May be supported by evidence but can be refined, revised, or discarded as new evidence is uncovered.

Experimenting

The process of testing a hypothesis or prediction by gathering data under CONTROLLED CONDITIONS.

Controlled Experiment

• Comparison of a control group with an experimental group.

• Groups are identical except for 1 factor.

• Control Group has nothing “new” happening to it. The same old, same old.

• Experimental Group – has the independent variable applied (something “new”).

Variables

• Independent Variable – the factor that the scientist manipulates.

• Dependent Variable – the factor that the scientist observes or measures.

• Ex:

Analyzing Data and Drawing Conclusions

• Data has to be organized.

• Charts, Graphs, paragraphs, etc.

• Process of determining if data is reliable

• Does it support hypothesis?

Theory

• A broad and comprehensive statement of what is thought to be true.

• Supported by considerable evidence.

• May tie together several related hypotheses.

• Few true theories are produced in science.