Science Starter- 9/14 Consider the following and answer the questions in your notebook: Scientists in City A spent two hours one evening catching fish in a stream using an experimental new bait and caught 5 fish, while scientists in City B spent three hours one morning catching fish in a lake using the same bait and caught 2 fish. They could not reach any conclusion about how many fish a person can catch using the bait. 1. What are the factors that led to the different results? 2. What are some practical ways the scientists could reduce variation ?

S CIENCE S TARTER 9/17/12 Grab the papers off the blue chairs! Give an example of something that has variation and explain why. What is a trial? If you have precision, then what does that mean?

P LOT YOU CLASSES D ATA I will wait only a couple of minutes... Then answer the question... -Do you think your class’s data is reliable? -Why or Why not?

D EFINE : -R EPEATABLE -R EPLICATE -D ISTRIBUTION /V ARIATION D ISCUSS WHAT THESE WORDS HAVE TO DO WITH OUR DATA.

Reflection: -Do you think you can design a procedure so that everyone gets the same results? *Talk with your group to come up with some procedures, then we will bring it together as a class.*

N EW P ROCEDURES BLK 1 Must drop on tails Pipette must drop in middle of penny Squeeze the pipette for 2 sec. for a full drop to come out Make it so one full drop comes out Hold pipette vertical when dropping Penny need to be flat on table Have 3ml in pipette Hold pipette 1 in above penny

N EW P ROCEDURES BLK 3 Same type of penny Do 2 trials of heads and two with tails Have pipette close to penny (1 cm) Penny must be on flat surface (on counter) 3ml of water in pipette Make the pipette still when dropping Pipette must be held sideways Squeeze at a rate of one drop every 2 sec.

N EW P ROCEDURES BLK 4 Must drop on tales Pipette will be ¼ full when in use Drops will be at the same rate (on Diana’s count) 3 sec. drops (Diana’s count) Drop must be in center Pipette must be vertical Drops from ½ the penny 3 trials Put penny on counter & no touching the counter We must be quiet to not get destracted and hear Diana

N EW P ROCEDURES BLK 5 Same size pipette One drop at a time Same amount of water in pipette (2 ml) Put drops on tails side Drops released ½ in above penny Let water settle every 3 sec (By Jaicie) Penny must be on flat counter Drops in the middle of penny 3 sec squeeze (By Jaicie) Hold the pipette vertically