1. Community College of Baltimore County
Scientific Method
Karen J. Dalton
Community College of Baltimore County
Catonsville Campus

2. What is the problem? Ask a question?
Observations
What you know before you begin an experiment
Accepted scientific knowledge
Journals, textbooks
What you see in the world around you
What did Semmelweis observe?
What is the problem? Ask a question?
What did he ask?
Hypothesis: Educated answer to your question
Must be based on accepted science
What is your answer to Semmelweis’ problem?

3. Test you hypothesis Results Conclusions Experimental design
Control groups vs. experimental groups
Large numbers in the groups
Repeatable experiments
How did Semmelweis test his hypothesis?
Results
Data collected as a result of the experiment
Conclusions
What do your results mean?
Results are new observations
Should you now alter your hypothesis?

4. Theory
Well substantiated explanation of something in the natural world
Explanation uses many different pieces of evidence
Examples: cell, atomic, evolution, chromosomal inheritance
In science this is “as good as it gets”
Lay people use the word theory when they should be using the word hypothesis