SCIENTIFIC METHOD System – specific portion of matter in a given region of space that is studied for experiment/observation. A systematic approach used in scientific study. Applies to all science. Provides organization Provides a way to verify results of research and experiments.

Steps of the Scientific Method Observation Hypothesis Experimentation Analysis Conclusion

STEP ONE OBSERVATION The art of gathering information Should be UNBIASED

The Result of Making Observations is… Data Qualitative data – describes with words Color, shape, smell Quantitative Data – describes with numbers 5 grams, 200 meters, 29 students

STEP TWO HYPOTHESIS An educated guess (informal definition) A TESTABLE statement or prediction A possible explanation for what has been observed.

Examples TESTABLE… If a ball is dropped from a rooftop, it will fall downward. Jackie got sick from eating ruined meat at a local restaurant.

Untestable…. Cancer is caused by invisible rays shot by aliens from outer space. Dogs make better pets than cats.

STEP THREE Experimentation A set of controlled observations that tests the hypothesis. An experiment should test only ONE variable at a time. A variable is a condition in an experiment that can have different values.

Two Types of Variables Independent variable – the condition in an experiment that will be changed. Under the experimenter’s control. Dependent variable – the condition in an experiment that changes in response to the independent variable “depends” on the outcome of the experiment

Every good experiment also needs… A control A control is a standard of comparison The control never is changed or experimented upon Example: When studying the effect of a drug on a lab rat, you must have a nearly- identical rat that is not given the drug.

STEP FOUR ANALYSIS Data from experiments must be carefully analyzed using many different methods Charts, graphs, computer sorting Experimenters will look for PATTERNS in the data

STEP FIVE CONCLUSION A judgment based on the INFORMATION OBTAINED from the analyzed data Hypothesis are never “proven” but rather, may be SUPPORTED by the data It is more common for the data NOT to support the hypothesis. In that case, experimenters must return to step 2 and make a new hypothesis.

Theory vs. Law Theory – an explanation that has been supported by many experiments. States a broad principle of nature supported over time May be modified Is considered successful if it can make new, true predictions Tells WHY things happen in nature

LAW States a relationship in nature that is the same with NO exceptions Supported by many experiments May be modified Tells WHAT will happen in a given situation

MODEL Model – an explanation of how phenomena occur and how data/events are related Can be physical, mathematical, computerized, or simply drawings/words Stop

Types of Scientific Research Pure research – seeking knowledge for the sake of knowledge Ex. – studying the behavior of ants to write a paper Applied research – seeking to solve a specific problem Ex. – Research on alternative fuels Chance discoveries – an unexpected find while doing research on another subject Discovery of nylon Discovery of radiation

Most Important Aspect in Research is… SAFETY! In the lab, YOU are responsible for your own safety and the safety of others around you

Benefits of Chemistry When unexpected problems arise, existing research gives a good place to start looking for answers TECHNOLOGY – the practical use of scientific information