2. Bias and Experimental Error

3. Bias  Bias is an inclination or preference that influences judgment; prejudice.  This means that the scientist(s) favor towards a specific ending for the experiment.  You can be biased in favor of something or biased against it.  A bias is based more on feelings and opinions than on facts.

4. Example Pigeons are dirtier than you think. They eat trash and leave their droppings wherever they go. Pigeons also carry diseases. One time, I was bitten by a pigeon when I tried to shoo it away. I had to get a shot because the pigeon might have given me a disease. Is the author of this paragraph biased? If so, are they biased for or against pigeons?

5. Experimental Error  Experimental error is when the experimental measurements are different from the actual measurements.

6. Error Example 1 Professor Messer is trying to measure the length of a piece of wood: Discuss what he is doing wrong. How many mistakes can you find?

7. Error 1. Measuring from 100 end 2. 95.4 is the wrong number 3. ‘mm’ is wrong unit (cm) 4. Hand-held object, wobbling 5. Gap between object & the rule 6. End of object not at the end of the rule 7. Eye is not at the end of the object (parallax) 8. He is on wrong side of the rule to see scale. Answers: How many did you find?

8. Look at this top-pan balance: There is nothing on it, but it is not reading zero. What effect do you think this will have on all the readings? It has an error.

9. Intended Benefit and Unintended Consequence  An intended benefit is the purpose or reason the technology was created.  An unintended consequence is the result or uses that the engineer never expected the technology to do. Can be beneficial! iPad: Intended benefit: can connect to the internet anywhere that has WiFi Unintended consequence: health issues

10. Examples 1. A vacuum company wants to create a new vacuum that has a stronger suction and will pick up dirt easier. They design it so that the vacuum works more efficiently. After many people start using the vacuum, they notice that the vacuum belt wears out easily and must be replaced often. This belt wearing out is: a) a positive unintended consequence b) an intended benefit c) a negative unintended consequence 2. Airplanes provide fast travel and allow us to reach many places in the world. Which of the following is likely a positive unintended consequence of the airplane being built? a) sending mail across our country or even world quickly b) airplane crashes c) people being able to fly