Which team is the fastest?

1. Which team is the fastest? • You will be split into your squads to compete against each other • You must stand in a single file line behind your team’s desk • One at a time you will take your utensil, go under the desk and speed walk (NO running) to the middle table • Take a scoop of candy and speed walk (NO running) back to your team’s desk and dump the candy into your container • You can only use one hand when scooping, walking back to your desk and dumping your candy • Any dropped candy, on the desk or floor, cannot be retrieved • Hand your utensil to the next person in line and go to the end and it’s their turn to get candy for your team • The game is over when the teacher yells “STOP” • Count your candy to decide which team was the best

2. Was this a fair test? • Why not? • Didn’t have the same sized utensil • Didn’t keep a constant container size • Didn’t maintain an equal distance between each team’s desk and the middle table • How can we make it fair? • Ensure every team the same materials • utensil, distance from middle and container

4. Making a Fair Test

5. Is it fair? • Think of different times in your life you said “that’s not fair” • Why weren’t they fair? • How can you make them fair? • Scientist must ensure that all of their experiments are fair or else they may not be accurate • Think about the cartoon at the beginning of this lesson • Which animal will win? • Can you make a test that is more fair?

6. http://www.youtube.com/watch?v=SPZRtlqBgYk

7. Variables • Anything that can be changed or altered in an experiment • For example, to find the effect that light has on plant growth you could change the amount of light on two plants • put one plant in a sunny window and one in a dark closet • If I study then I will get good grades • Is this statement true? • What else can effect the outcome? • Sleep, previous knowledge/class notes, proper nutrition, quiet workspace, proper lighting • These are all variables that can effect the outcome of your study because they can be altered or controlled

8. Independent vs dependent • What does it mean to be dependent? • To rely or need something • What do you think a dependent variable is? • A variable that if effected by or relies on another • Ex., Your grade is dependent on how much you study • Grade is the dependent variable • Independent variable is the one that causes the dependent to change • Ex., The amount of time you study • This is the variable that you change in your experiment to see how it will effect the dependent variable • You will have someone not study, study for one day or study for a week to see who has the better grades

9. Which is which? • How do you know which variable is the independent and which is the dependent? • Put the two variables into this sentence • (Independent variable) causes a change in (Dependent Variable) and it isn't possible that (Dependent Variable) could cause a change in (Independent Variable). • For ex., (studying) causes a change in (grades) and it isn't possible that (grades) could cause a change in (studying). • We see that “studying" must be the independent variable and “grade” must be the dependent variable because the sentence doesn't make sense the other way around • The variable you are measuring or observing is the dependent variable and the one you are manipulating is the independent

11. If....then statements • Once you know the two variables in your study you must make an If...then statement • If...then statement is called a hypothesis • A prediction of what you think will happen during your experiment based on previous knowledge • The independent variable is the ifand the dependent is the then part of the hypothesis • If I had a computer (independent), then I’ll get better grades (dependent) • Can anything else effect your grades on your book report? • Sleep, diet, outside help, editing, vocabulary, grammar, notes on each chapter/summaries, etc.

12. Constant Variables • To properly test your hypothesis you must keep the other factors that effect your grades constant or the same • Everyone must get a good nights sleep, eat the same meal, have no one else help you or have only the teacher help you, provide notes for each person • You must try to keep every variable constant except the independent and dependent variable • Sometimes it is not possible but then the outcome of your study is not 100% valid or reproducible

13. Constant Variables • To properly test your hypothesis you must keep the other factors that effect your grades constant or the same • Everyone must get a good nights sleep, eat the same meal, have no one else help you or have only the teacher help you, provide notes for each person • You must try to keep every variable constant except the independent and dependent variable • Sometimes it is not possible but then the outcome of your study is not 100% valid or reproducible

14. Review • Independent variable = • The cause variable • Dependent variable = • The effect variable • Constant variable = • Hypothesis = what I control during the experiment what I observe during the experiment what I keep the same during the experiment the If...then statement that predicts the outcome of your experiment based on previous knowledge

15. Exit Card • Tell me the independent and dependent variable of the candy game • What are the constant variables and why are they important? • Write the If...then statement/hypothesis for the activity • Homework: • Will eating chocolate bars cause acne? • Make a fair test to answer this question including hypothesis and constant variables