Log Seven Debrief Floating and Sinking / Incomplete Data and Replication

1. Log Seven DebriefFloating and Sinking / Incomplete Data and Replication

2. Bias • The influence of a person’s belief or wishes on their opinions or interpretations. • Bias in science is BAD… Science must stay fair and be grounded in evidence and data.

3. Qualitative Observation • Observations that are acquired with our five senses… numbers are not involved. • The dog is black and white. • The heating pad is turned on and feels hot.

4. Quantitative Observation • Observations that are acquired with tools that give us numbers and measurements. • The dog has a mass of fifty pounds. • The heating pad has a high temperature of 110°F.

5. Replicate • to repeat • It’s a good thing in science if a lab report is written so well that another scientist can follow the exact same steps and get the same results. • Replicating experiments make results more valid and reliable.

6. Meniscus • The little curvy line thingy! Read the bottom of it… not the sides.

7. Water level 1.A student conducts an experiment to see how unopened cans of soda will behave in cold water. She fills a ten-gallon aquarium with eight gallons of water. She drops a can of Coca-Cola and a can of Mt. Dew in the aquarium. Both cans sink to the bottom of the tank. Predict what will happen if she drops a can of Pepsi-Cola and a can of Diet Coke. Explain both of these predictions. But what about this… click link Dear Ms. Back… if you have a gram stacker balance… I can’t remember what they are called… Ohaus I think… Use gram stackers to determine the mass of the pop cans… then divide by the volume in milliliters listed on can…. this is density… If you don’t have balance… send one of your little darlings down… Greene

8. 2.Students do an investigation on the reaction of baking soda with vinegar. They create the data table above to record the mass (grams) and temperature (degrees Celsius) of the mixture every 5 seconds. Several pieces of data are missing from the table.In your answer, give one example of how the incomplete data make it difficult for the students to draw conclusions about the changes that occur when baking soda reacts with vinegar. Also, explain how the incomplete data will affect the ability of other students to replicate (reproduce) the experiment. • Scientists can sometimes “extrapolate” or predict missing data… but this is a risky business… There is really no way of safely assuming data that is missing. Guessing is not a scientific way of getting data. • Replicating this data would be difficult because the scientist wouldn’t know how many grams of baking soda to use to start the experiment…