Intro to lab design and terms

 We are going to have a contest.  But how will we know which is best?  Which would be the most difficult to measure? Why?  Which would be the least difficult to measure? Why?  Lets try it out!  Make a paper airplane and write your name on it

 You can use scissors, paper clips, tape, staples or any other material available.  Make a guess as to what effect this change will have on your plane. (What do you think will happen to the airplane with these changes….Hopefully fly further)  Lets go try it again and see if you are correct.

 Hypothesis - an educated guess as to what will happen in an experiment.  If actual outcome is known, then it is really not a hypothesis.

 Was it fair to only have one throw for the winner? Why or Why not?

 Repeated trials - it reduces the effects of error or chance on the overall results.  How many times do you think would be good to test in labs?

 Refold?  Add paper clips?  Add tape?  Anything else?

 Wing shape  Shorter body?  Moved the center of gravity?  Changed the weight of the plane?  Anything else?  Did you change more than one thing?

 If you made more than one change, which change affected it the most? DO YOU HAVE PROOF?  The independent variable - ONE PURPOSEFULL CHANGE that effects the desired outcome (or dependent variable)

 Flight time  Total distance  Path it traveled  Anything else?

 A RESPONSE TO CHANGE  (THIS IS WHAT CHANGED BECAUSE OF INDEPENDENT VARIABLE.)

 Size of paper  Texture of paper  Weight of paper  Color of paper  Shape of wings  Anything else

 The things that remained the same.

 How do you know if the thing you changed (independent variable) was the thing that actually made it change?  You must fly one unmodified plane in each trial to see if its flight remained the same.

 A control is what every other trial is compared against.  The first plane we threw was the control because we compared all the rest of the throws to it.

 Brainstorm ideas - develop a purpose for the experiment  What will you keep the same?  - constants  What will you change?  - IV (Independent Variable)  What do you think will change because of it?  - DV (Dependent Variable)  What will you use to compare the results?  Control

 How do you know what happened in the experiment was not a fluke?  Repeated trials – good to have at least 3 but 5 is better.  What do you think will happen?  Hypothesis – Please write in the form of If…IV, then…..DV