Disease Detectives B/C

[megan_scioly]

Are the diseases being tested limited to the ones on the FDA chart? Thanks.

[WhatScience?]

Are the diseases being tested limited to the ones on the FDA chart? Thanks.

They are not...that is however, a good place to start

[megan_scioly]

Are the diseases being tested limited to the ones on the FDA chart? Thanks.

They are not...that is however, a good place to start

Thanks! What other diseases should we be looking at?

[Private Wang Fire]

Are the diseases being tested limited to the ones on the FDA chart? Thanks.

They are not...that is however, a good place to start

Thanks! What other diseases should we be looking at?

The FDA ones are some of the more common ones on the test. There is no "list" for all the diseases, you could just go check out WIkipedia or dig through google and keep your own running list of foodborne diseases & info about them.

[Nerd_Bunny]

They are not...that is however, a good place to start

Thanks! What other diseases should we be looking at?

The FDA ones are some of the more common ones on the test. There is no "list" for all the diseases, you could just go check out WIkipedia or dig through google and keep your own running list of foodborne diseases & info about them.

Lots of the practice tests on the exchange have disease related questions that aren't on the FDA list. If you take information from them then you're probably 90% good for possible disease questions at your tournament.

[Nerd_Bunny]

The p-value is just the name for the result of a chi-square test, right? The textbook I'm using is using too much crazy fancy talk to help me understand. I need a life of fred explanation for this.
EDIT: After some further reading I've discovered that this isn't the case, but I'm having trouble putting values into that chart they use to find the p-value. How are we supposed to use it?

[Froggie]

So, just to make sure, Div B doesn’t need to know Chi squares right?
But just in case (you never know what event supervisors do), how does it work?
7th grade math words please.

[Nerd_Bunny]

So, just to make sure, Div B doesn’t need to know Chi squares right?
But just in case (you never know what event supervisors do), how does it work?
7th grade math words please.

Div B doesn't need them, but I'll try to explain. I don't know the part about p-values yet, but I can calculate the chi-square stuff.

So get your 2x2 table and make it like this (warning hard to type without graphs):

Sick | Well | Total

Exposed |a| |b| |n1|

Not exposed |c| |d| |n2|

Total |n3| |n4| |N|

Then you take those values and put them into here:

x^2 = (N(ad - bc)^2)/n1*n2*n3*n4

Then it's just some basic algebra and following order of operations. I hope this is easy enough to understand and is all correct.

After you've gotten your number for x^2 (don't take the square root of it to make it just x) you compare it to a chart and I think that's how you get the p-value, but I'm not quite sure yet. The chart looks like this:

Chi-square value Probability (p)
> 10.83 ||| < 0.001
> 6.64 ||| < 0.01
> 3.84 ||| < 0.05
< 3.84 ||| > 0.05

I hope this helps and I didn't just confuse you.

[Froggie]

So, just to make sure, Div B doesn’t need to know Chi squares right?
But just in case (you never know what event supervisors do), how does it work?
7th grade math words please.

Div B doesn't need them, but I'll try to explain. I don't know the part about p-values yet, but I can calculate the chi-square stuff.

So get your 2x2 table and make it like this (warning hard to type without graphs):

Sick | Well | Total

Exposed |a| |b| |n1|

Not exposed |c| |d| |n2|

Total |n3| |n4| |N|

Then you take those values and put them into here:

x^2 = (N(ad - bc)^2)/n1*n2*n3*n4

Then it's just some basic algebra and following order of operations. I hope this is easy enough to understand and is all correct.

After you've gotten your number for x^2 (don't take the square root of it to make it just x) you compare it to a chart and I think that's how you get the p-value, but I'm not quite sure yet. The chart looks like this:

Chi-square value Probability (p)
> 10.83 ||| < 0.001
> 6.64 ||| < 0.01
> 3.84 ||| < 0.05
< 3.84 ||| > 0.05

I hope this helps and I didn't just confuse you.

Thank you so much! I understand now!

[Nerd_Bunny]

I accidentally took a practice test a while ago that I had no idea where it came from. The front cover only has the Science Olympiad logo and these words:
Disease Detectives
The starred questions can be used as tie breakers.
Total points: 212

The first section of questions is about Lyme Disease, the second part is about Severe Stomach Illness, the third part is about Happy Farms Drug Company, and the fourth part is about General Epidemiology Knowledge and Advanced Statistics. If anyone knows where this test came from, or where it didn't come from, I would be really happy because I don't have an answer key or a way to reproduce this really good test.