2. Two Types of Research  qualitative descriptive research generally based on observable data only Example: ○ A field biologist may observe coral reefs in order to determine if the loss of this habitat would threaten the extinction of many species that live in the coral reefs.

3.  quantitative research based on the collection of numerical data—usually by counting or measuring Example: ○ a sociologist collects data from universities to see the increase in college degrees attained since 1990

4. Forming and Testing Hypotheses  hypothesis a possible explanation of a question or problem that can be formally tested

5.  Scientists describe an experiment as a procedure that tests a hypothesis by the process of collecting information under controlled conditions.  Controlled experimentation is carried out by keeping all the variables constant, except the one under study.  controlled variables conditions that are held constant throughout the experiment

6.  the variable under study is the independent variable in a controlled experiment, it is the variable that is being changed  on a graph, the independent variable is positioned on the x-axis

7.  the changed conditions are called the dependent variables the result or change that occurs due to the part of an experiment being tested  on a graph, the dependent variable is positioned on the y-axis

8. What is the purpose of this study? What is the independent variable? What is the dependent variable?

9. Pull out your homework from Friday, 3/11. Lesson #4: Independent Practice High Protein Diet and Growth Rate of Rats