Warm-up August 29, 2008: Scientific Method Anticipation Guide
The Scientific Method
• SCIENTIFIC METHOD= a logical or systematic approach to solve a problem • Steps in the scientific method are not always performed in a specific order
Steps in the Scientific Method
• A. OBSERVATION = suggests questions to investigate • Usually involves the senses – qualitative data
• B. Asking A Question • C. Collecting Data 1. Observing 2. Measuring Quantitative data can be measured in numbers 3. Sampling Using a small part to represent an entire population 4. Organizing Data
• • • •
D. Hypothesizing 1.Forming a hypothesis 2.Predicting EX: If Homer eats 20 Hershey bars a day, then he will get stomach aches. HYPOTHESIS= an educated prediction or a testable explanation. A hypothesis is stated in the “if… then… form.
• E. Experiment • 1. Conduct a controlled experiment • 2. Analyze data . In a controlled experiment, there is 1. an experimental group (experiences change in one variable) and • 2. a control group (experiences no change).
• F. Drawing Conclusions • 1. Modeling • Model – an explanation supported by data • 2. Inferring • Inference – a conclusion made on the basis of facts or premises rather than on direct observation • 3. Forming a Theory • Theory = a broad and comprehensive statement of what is thought to be true
• G. Implementing Scientific Methods • 1. Problem Solving • 2. Communicating
Example
• OBSERVATION: • Ninth graders eat a lot of Hershey bars.
• HYPOTHESIS: • If ninth graders eat a Hershey bar after lunch, then they will exhibit “hyper” behaviors.
• PREDICTIONS: • We will observe many different hyper behaviors • CONTROLLED EXPERIMENT: • One half of ninth graders eat a free Hershey bar with lunch (experimental group). • One half of ninth graders receive no Hershey bar at lunch (control group).
• Define hyper behaviors: • Toe tapping, pencil jiggling, humming etc. • Record hyper behaviors
Experimental Variables
• INDEPENDENT VARIABLE= the condition that is changed by the experimenter ( giving Hershey bars)
– Placed on the x-axis of a graph
• DEPENDENT VARIABLE = condition that depends (responds) to the independent variable. ( hyper behaviors)
– Placed on the y-axis of a graph
• SUMMARY: • A. A scientist’s work needs to be reviewed, re-tested, and verified. • B. Your hypothesis must be testable. • C. In a controlled experiment, there is 1. an experimental group (experiences change in one variable) and • 2. a control group (experiences no change).