1.3 Scientific Methods I. Intro A. The scientific method 1. A specific protocol that scientists follow in order to solve a problem or answer a question B. Why have a specific protocol? 1. Scientific questions are often difficult to answer a. A structured protocol makes it slightly easier 2. Validity a. Shows your steps in supporting questions b. Allows others to duplicate

Demo: As you watch the demo, write down 2-3 observations. Be as specific as possible! II. The scientific method A. Observing 1. Looking at the world around you 2. Something you notice with your five senses 3. All scientific understanding of the natural world is based on observation B. Inference 1. An idea/explination/conclusion based on observations and prior knowledge

C. Collecting data 1. Data a. Any and all information that scientists gather in trying to answer their questions 2. There are 4 important aspects of collecting data a. Observing b. Measuring 1. Quantitative data a. Data that can be measured in numbers

a. Data that CANNOT be measured in number 2. Qualitative data a. Data that CANNOT be measured in number c. Organizing data 1. Representing data in a graph, chart, table, or map D. Hypothesizing 1. Hypothesis a. A possible explanation based on observations made and data collected b. A proposed explanation of an observed phenomenon that can be tested. 1. A statement is testable if evidence can be collected that either supports it or disproves it c. Written as an “IF . . . . THEN . . . .” statement 1. “IF . . . [I do this], THEN . . . [This will happen]

IF people share needles THEN . . . . Possible for people to contract HIV c. A hypothesis can either be supported or disproved 1. It cannot be proved true beyond all doubt D. Experimenting 1. The process of testing a hypothesis or prediction by gathering data under controlled conditions 2. Elements of an experiment a. Controlled experiment 1. Based on a comparison of a control group with an experimental group a. The control and experimental groups are designed to be identical except for the one factor being tested 1. Control group a. The group that you do not change 2. Experimental group a. The group that is different by the one factor 2. Independent Variable a. The variable the investigator will manipulate, change b. The variable that causes a change in the dependent variable

3. Dependant Variables a. The variable the investigator will measure b. What the investigator thinks will vary during the experiment 3. Analyzing data/Conclusion a. Determining whether data collected during the experiment supports or does not support the hypothesis