How We Study the World: The Scientific Method

Scientific Method -- Definition Way of obtaining knowledge about the world in a series of steps No one method used by all scientists Based on evidence

Scientific Method -- Steps Step 1: Identify a problem Where do scientific questions come from? Observation Senses Tools Sight Hearing Touch Taste Smell Computers collect data

Observations Examples of an observation: Bees are attracted to red flowers. The highest temperature today was 105 degrees F. Observations can be recorded as data Data can be qualitative or quantitative – Qualitative data – descriptions – Quantitative data – anything that is expressed as a number

Activity Break On your note paper, write down as many observations as you can about the plant in the front of the class

Observation vs. Inference Observation What you can detect with your senses or with tools Inference A conclusion made from evidence or reasoning based on observations

Scientific Method -- Steps Step 2: Make a hypothesis (plural, hypotheses) Possible explanation for an observation An educated guess Usually an “if…then” statement (IF _________ is true, THEN_______ will happen) Combines explanation with prediction to show relationship that can be tested

Examples of Hypotheses Example 1: Observation: Bees are attracted to red flowers. Hypothesis: If bees are attracted to the red pigment in flowers, then they will fly towards red artificial flowers, but not yellow ones. Example 2: Observation: Daisy flowers grow in sunny places. Hypothesis: If a daisy flower needs sunlight to survive, then it will die when planted in a dark room.

How to recognize a hypothesis “if…then” Example: If plants grow toward sunlight, then a plant will grow in the direction of a window when placed next to one. “I think…” Example: I think the plant will grow in the direction of the window because plants grow toward sunlight.

What Makes a Good Hypothesis? A good hypothesis: 1.Explains all the observations 2.Is testable 3.Is simple, while still doing 1 & 2