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Today is Wednesday, September 4 th , 2013

In This Lesson: Unit 0 Nature of Science (Lesson 1 of 4). Syllabus receipts can go in the turn-in box. Today is Wednesday, September 4 th , 2013. Pre-Class – Draw a conclusion from the following data. Write it down in your notebooks. [Don’t over-think it].

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Today is Wednesday, September 4 th , 2013

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  1. In This Lesson: Unit 0 Nature of Science (Lesson 1 of 4) Syllabus receipts can go in the turn-in box. Today is Wednesday,September 4th, 2013 • Pre-Class – Draw a conclusion from the following data. Write it down in your notebooks. [Don’t over-think it] • In the late 1990s, a study by the University of Pennsylvania Medical Center found that children who often sleep with the lights on tend to later develop myopia (nearsightedness).

  2. Today’s Agenda • Briefly mention the Enlightenment • Or, a VERY brief look at a critical moment in the history of science. • Review the Scientific Method • Yep, that old friend. • Meet a horse that could count • His name was Hans.

  3. Let’s start with the horse. • It’s 1891. Meet Hans:

  4. Clever Hans • How could this be? Any ideas? Could Hans really count? If he couldn’t, what was he doing? • I need a volunteer. I promise it’s nothing embarrassing.

  5. The Nature of Science • What does this mean to you? • The Enlightenment: http://smarthistory.org/assets/images/images/wright.jpg

  6. Heliocentrism versus Geocentrism • Galileo, Copernicus, Kepler: Actually, this thing around my neck is the center of the solar system. http://en.wikipedia.org/wiki/File:Justus_Sustermans_-_Portrait_of_Galileo_Galilei,_1636.jpg http://en.wikipedia.org/wiki/File:Johannes_Kepler_1610.jpg http://en.wikipedia.org/wiki/File:Nikolaus_Kopernikus.jpg

  7. Clever Hans • So Clever Hans couldn’t happen today, right? • Not so fast. • Shiloh the Wonder Horse

  8. Returning to Univ. of Penn… • What about that myopia study? Was something else going on there? • If you’re not sure, consider this: • In any experiment, there can really only be one variable studied at a time.

  9. Too Many Variables • The fact is that the University of Pennsylvania was dealing with too many variables. What do I mean by this? • A variable is something you’re changing and/or studying in an experiment. • Example: “Lights” or “no lights” was a variable in the UPenn study. • A constant is something that does not change in an experiment. • Example: All the test subjects were children of a similar age (they weren’t testing senior citizens at the same time as infants).

  10. Controls and Constants • We’ll talk about this in more detail soon, but for now, here’s the difference (in short terms): • Constant: Something kept the same. • Control: Something kept normal. • Example: A brand new type of train engine allows it to pull a train for 3000 miles before needing to be refueled. Is the new train better than old ones?

  11. Too Many Variables • In the case of the University of Pennsylvania, the researchers were dealing with one variable that they know of (the lights) along with one they didn’t know of… • The kids’ parents. • As it turns out, for whatever reason, parents that are nearsighted are more likely to leave the lights on for their children as they sleep. • The children develop myopia later in life not because of the lights, but because myopia is a genetic condition.

  12. Lessons to be learned… • There are three lessons to be learned from the UPenn study: • 1. Correlation does not equal causality. • Basically, because two things occur together doesn’t mean one causes the other. • 2. Things are not always as they seem. • Video! • Stroop Test • 3. Good experimental design is worth a lot. • We’ll talk more about this next class, too.

  13. Experimental Design • You’ve seen the scientific method before. What are the steps? • Identify problem • Form hypothesis • Design/perform experiment • Gather/analyze data • Draw conclusion • Really, however, the names you give these steps are not important. It’s how you think about them.

  14. Experimental Design • You’ve seen the scientific method before. What are the steps? • Identify problem • Form hypothesis • Design/perform experiment • Gather/analyze data • Draw conclusion • Really, however, the names you give these steps are not important. It’s how you think about them.

  15. Example 1 • In an experiment to determine whether or not apples ripen faster in chambers of carbon dioxide than in oxygen, a student performs the following procedure: • Place one apple in plastic box containing only CO2. • Place another apple in a cardboard box containing only O2. • Record time taken to ripen. Compare and conclude.

  16. Example 2 • In an experiment to determine whether or not apples ripen faster in chambers of carbon dioxide than in oxygen, a student performs the following procedure: • Place one apple in sealed box containing only CO2. • Place another apple in a duplicate sealed box containing only O2. • Record time taken to ripen. Compare and conclude.

  17. Experiment 3 • Before the apple-ripening experiment, the student hypothesizes that the apple in CO2 will ripen faster. • After the apple ripening experiment, the student finds that the data do not show any significant change. In light of these results, the student should: A: Change his/her hypothesis. B: Redesign and rerun the experiment. C: Accept his/her conclusion as it is, assuming there’s no apparent source of error.

  18. Experiment 4 • You may have heard of the Pepsi Challenge. • If you haven’t, this was a marketing technique (and use of the scientific method) by Pepsi. • In the test, a “test taker” is given two blank cups, one of which contains Pepsi, one Coca Cola. He/she doesn’t know which is which. • The “test taker” tries a sip or two of each and decides which he/she likes better. Most people seem to take Pepsi.

  19. But wait… • Should we assume Pepsi is better than Coke? • As it turns out, Pepsi is picked more frequently because it is sweeter, and people tend to like sweeter drinks in small doses. • However, in larger doses (like a bottle of soda), people don’t like things that sweet. That’s why Coca-Cola remains more popular overall. http://www.stephendenny.com/wp-content/uploads/2010/03/pepsi-challenge.jpg

  20. Now then… • The scientific method is used all the time, even if it’s not always used formally. • You use it probably every day, too, and especially when you make decisions. • However, there happens to be a great example of a group of people that use the scientific method as a basis for a television show. • Anyone know what show it is?

  21. So now then… • What does science mean to you? • Surveys… • Homework: • Ask your parents/guardians what science means to them, but don’t tell them what we’ve talked about today first. We need honest answers. • Write down what they say, and your answer to the same question. [worth 20 points] • We will [anonymously] discuss some tomorrow.

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