1.2 Scientific Methods

I. Beginning a Scientific Investigation A. Making Observations 1. def- act of perceiving objects or events by using the senses 2. Direct observation a. ex.- Seeing Canadian geese 3. Indirect observation b. ex.- gravity can’t be seen, only its effects can be studied

B. Formulating a Hypothesis 1. A possible explanation that can be tested 2. a.k.a. – an educated guess II. Controlled experiments A. Carried out under controlled conditions B. Tests one factor at a time C. Control Group 1. Standard for comparison D. Experimental Group 1. Same as control group except one factor

E. Independent Variable 1. the one factor that changes in an experiment F. Dependent Variables 1. change in response to the independent variable III. Study without experiments A. ex.- linking smoking to heart disease IV. Analyze Results A. Results may or may not support your hypothesis

V. Drawing Conclusions A. Results need to be explained at the end of experiments VI. Considering Bias A. Sometimes scientists point of view may influence experimental conclusions VII. Scientific Theories A. General explanation for a broad range of data 1. ex.- theory of evolution