Predicting and Hypothesizing

Prediction An expectation of what will be observed An expectation of what will be observed A forecast about what will happen A forecast about what will happen Based on prior knowledge and data that has been collected Based on prior knowledge and data that has been collected

How do you make accurate predictions? Make observations. Recall past experiences Make observations. Recall past experiences Use your knowledge to search for patterns in data. Make inferences Use your knowledge to search for patterns in data. Make inferences Make predictions about future events Make predictions about future events Test those predictions to determine validity Test those predictions to determine validity After testing, revise predictions if necessary After testing, revise predictions if necessary

Hypothesis Tentative explanation for an observation Tentative explanation for an observation Inference about why something might happen Inference about why something might happen Written in an If… Then…. Because… statement Written in an If… Then…. Because… statement The results of an experiment cannot prove that a hypothesis is correct, rather the results either support or not support (refute) the hypothesis The results of an experiment cannot prove that a hypothesis is correct, rather the results either support or not support (refute) the hypothesis

If….. Then…. Because… If (independent variable) what you changed on purpose If (independent variable) what you changed on purpose Then (dependent variable) what you will measure Then (dependent variable) what you will measure Because - Your inference (explanation) of why you think it will happen. Because - Your inference (explanation) of why you think it will happen.

Example Independent Variable – length of paper thing blades Independent Variable – length of paper thing blades Dependent Variable – rotational speed Dependent Variable – rotational speed

Telephone Independent Variable – length of string Independent Variable – length of string Dependent Variable – clarity of sound Dependent Variable – clarity of sound

Baseball Independent Variable – baseball batting practice Independent Variable – baseball batting practice Dependent – batting average Dependent – batting average

Drink Mix Independent Variable – temperature of solution Independent Variable – temperature of solution Dependent Variable – dissolving time of powered drink mix Dependent Variable – dissolving time of powered drink mix

Green club Murphy and Sam joined green club and want to increase recycling of aluminum cans. They want to see if putting up posters will increase recycling of aluminum cans.

Making Paper airplanes Make two different styles of paper airplanes Make two different styles of paper airplanes Make a prediction which one will fly a longer distance? Make a prediction which one will fly a longer distance?

Paper airplanes Which one flew further? Which one flew further? Write a hypothesis If… Then… Because… Write a hypothesis If… Then… Because… How could you test your hypothesis? How could you test your hypothesis?