Scientific Models, part 2

August 24, 2015(1.2 in your books)

Meme Moment

Scientist of the Day

Frances Oldham Kelsey

• Went to college at 15• Mistaken for a boy• Found a chemical being added

to medicines that was killing people

• Stood up to corporations that wanted her fired

• Sent her friend to investigate another dangerous medicine

• Kept thalidomide out of the US (saved thousands of babies)

VocabularyPersonal bias: You think one thing, so you think everyone will think that too.

Cultural bias: Everyone around you when you were growing up seemed to think or do something, so you think everyone in the world will think/do that too.

Experimental bias: An experiment doesn’t have a good design, so you’re more likely to get one particular result.

6th and 7th grade

Deductive vs Inductive• Two ways to classify scientific reasoning

• Deductive reasoning starts with other knowledge.

• Inductive reasoning starts with observations (like Sherlock Holmes).

• Scientists usually like deductive reasoning more, but inductive reasoning is still useful – it just has to be tested afterwards!

Deductive Reasoning

I already know...

New Observati

on

Conclusion

Something related to what you know, but not exactly the

same

Inductive Reasoning

New Observati

on

I also know...

Conclusion

Why might inductive reasoning be wrong?

• Inductive reasoning is useful (because it’s reasoning, not just wildly guessing), but it often draws the wrong conclusion.

• Inductive reasoning has to be backed up with more data.

• Example: This man has a beard. Graduate students are more likely to have beards. A razor is needed to remove a beard. Orthodox Jews grow beards. Hipsters like beards. Which piece of information leads to the right conclusion?

What if you get it wrong?

• Science fixes itself! Even when we get stuff wrong, we often learn more about the problem in the meantime

• It’s especially important to test conclusions from inductive reasoning with new experiments

• This week, we’ll talk about designing experiments from scratch and plan our first explosion!

What makes a good experiment?

• What are we looking for?• What do we expect to observe?• How could we record that? (8th grade: how could

we measure that as empirical evidence?)

• What variables do we have?• What controls do we have?

Friday

• Make a note!

• 2L bottle of any soda• 1 roll of any Mentos or

similar candy• Optional: poncho

Questions• Any questions about the slides?

• Any new questions?

Questions from Last Week

• Is there anti-venom for komodo dragons?I’m still not sure. One source said yes, another no.

• What type of oryx was reintroduced? Arabian oryx (Oryx leucoryx) into Oman, Bahrain, Saudi Arabia, Qatar, Jordan, Israel

• Are daddy longlegs the most poisonous type of spider?

No. And spiders usually aren’t poisonous. Poisonous is if you eat it. Venomous is if it stings or bites and injects venom that way.

http://spiders.ucr.edu/daddylonglegs.html

6th grade

6th grade

Questions from Last Week

• Are daddy longlegs a type of spider?It depends. 3 different types of bugs are called “daddy longlegs”

insect – crane fly arachnid, but not a spider(the usual daddy longlengs)

arachnid, cellar spider

6th grade

Questions from Last Week

• Are bush babies and lemurs types of monkey?

No, bush babies, aye-ayes, and lemurs are “prosimians” (actually in different suborders)

6th grade