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Re: Disease Detectives B/C

Posted: February 23rd, 2018, 6:06 pm
by GHamski
I would check out the Khan Academy videos on hypothesis tests in their AP Statistics section. I believe they released them just a few days ago. As for a formula, you are probably better off just bringing a calculator capable of performing the tests unless you bring along (or are given) a table of probabilities associated with t or z statistics such as http://apstatsmonkey.com/StatsMonkey/AP ... ources.pdf (pages 4-6). You can perform the tests in a TI-84 graphing calculator by hitting the STAT button, scrolling over to tests, and selecting Z or T test. Another good resource on this topic might be anybody in AP Statistics at your school, as I believe a lot of curriculums will have covered or be in the process of covering Z and T tests. Also, I'm new to this so I don't know how to reply directly to a comment. Sorry about that!

Re: Disease Detectives B/C

Posted: February 25th, 2018, 8:38 pm
by steminism
Nerd_Bunny wrote:What are the formulas for Z-tests and T-tests? I've already got the chi-squares and the cochran Mantel-Haenszel tests down, and Fisher's exact test is coming along, but it's been hard for me to find resources about these tests in an epidemiology context. Thanks!
care to share some wisdom on the cochran Mantel-Haenszel and Fisher's exact test? haha I've been struggling

Re: Disease Detectives B/C

Posted: March 1st, 2018, 7:20 pm
by UTF-8 U+6211 U+662F
Anyone have any information about who to contact after an investigation has been conducted?

Re: Disease Detectives B/C

Posted: March 2nd, 2018, 12:48 pm
by quantumk19
Does anyone have a resource on how to do chi squared specific to the Disease tests. We know how to use the formula and values, but we don't know which values constitute the "observed" and "expected" in a standard contingency table. What are the expected values?

Re: Disease Detectives B/C

Posted: March 2nd, 2018, 12:59 pm
by UTF-8 U+6211 U+662F
quantumk19 wrote:Does anyone have a resource on how to do chi squared specific to the Disease tests. We know how to use the formula and values, but we don't know which values constitute the "observed" and "expected" in a standard contingency table. What are the expected values?
I don't know too much about chi squared distributions, but I would assume the "expected" would be the null hypothesis, i.e. that there is no association between the exposure and the condition, and thus the expected value of people affected by the condition would be the attack rate of the whole population times the population exposed.

Re: Disease Detectives B/C

Posted: March 2nd, 2018, 1:05 pm
by Nerd_Bunny
EDIT: Ok my calculations are really bad. Please ignore me. :oops:

Re: Disease Detectives B/C

Posted: March 2nd, 2018, 1:43 pm
by Nerd_Bunny
UTF-8 U+6211 U+662F wrote:
quantumk19 wrote:Does anyone have a resource on how to do chi squared specific to the Disease tests. We know how to use the formula and values, but we don't know which values constitute the "observed" and "expected" in a standard contingency table. What are the expected values?
I don't know too much about chi squared distributions, but I would assume the "expected" would be the null hypothesis, i.e. that there is no association between the exposure and the condition, and thus the expected value of people affected by the condition would be the attack rate of the whole population times the population exposed.
I'm currently working on finding a good way to calculate this. Apparently a method I got from a practice test was wrong, so I gave out some misinformation earlier. So far it's been hard finding ways to calculate chi-squares in an epidemiology context, but I'm trying. I'll share the correct calculations here once I find them.
Sorry for double post.

EDIT: If anyone could look at the 2017 Princeton test and figure out how they got the answer to question 7 all our problems will be solved. It'a on the test exchange. I'll link to the test and key:
https://scioly.org/tests/files/diseased ... n_test.pdf
https://scioly.org/tests/files/diseased ... on_key.pdf

Re: Disease Detectives B/C

Posted: March 3rd, 2018, 8:12 am
by WhatScience?
Nerd_Bunny wrote:
UTF-8 U+6211 U+662F wrote:
quantumk19 wrote:Does anyone have a resource on how to do chi squared specific to the Disease tests. We know how to use the formula and values, but we don't know which values constitute the "observed" and "expected" in a standard contingency table. What are the expected values?
I don't know too much about chi squared distributions, but I would assume the "expected" would be the null hypothesis, i.e. that there is no association between the exposure and the condition, and thus the expected value of people affected by the condition would be the attack rate of the whole population times the population exposed.
I'm currently working on finding a good way to calculate this. Apparently a method I got from a practice test was wrong, so I gave out some misinformation earlier. So far it's been hard finding ways to calculate chi-squares in an epidemiology context, but I'm trying. I'll share the correct calculations here once I find them.
Sorry for double post.

EDIT: If anyone could look at the 2017 Princeton test and figure out how they got the answer to question 7 all our problems will be solved. It'a on the test exchange. I'll link to the test and key:
https://scioly.org/tests/files/diseased ... n_test.pdf
https://scioly.org/tests/files/diseased ... on_key.pdf
For question 7, I do believe that incubation period is the correct answer I have no idea what a latency period is but whatever.

Re: Disease Detectives B/C

Posted: March 3rd, 2018, 8:25 am
by Tailsfan101
WhatScience? wrote:
Nerd_Bunny wrote:
UTF-8 U+6211 U+662F wrote: I don't know too much about chi squared distributions, but I would assume the "expected" would be the null hypothesis, i.e. that there is no association between the exposure and the condition, and thus the expected value of people affected by the condition would be the attack rate of the whole population times the population exposed.
I'm currently working on finding a good way to calculate this. Apparently a method I got from a practice test was wrong, so I gave out some misinformation earlier. So far it's been hard finding ways to calculate chi-squares in an epidemiology context, but I'm trying. I'll share the correct calculations here once I find them.
Sorry for double post.

EDIT: If anyone could look at the 2017 Princeton test and figure out how they got the answer to question 7 all our problems will be solved. It'a on the test exchange. I'll link to the test and key:
https://scioly.org/tests/files/diseased ... n_test.pdf
https://scioly.org/tests/files/diseased ... on_key.pdf
For question 7, I do believe that incubation period is the correct answer I have no idea what a latency period is but whatever.
The latency period is the time between exposure and infection. The incubation period is the time between infection and when you start to show symptoms.

Re: Disease Detectives B/C

Posted: March 3rd, 2018, 8:26 am
by WhatScience?
Tailsfan101 wrote:
WhatScience? wrote:
Nerd_Bunny wrote: I'm currently working on finding a good way to calculate this. Apparently a method I got from a practice test was wrong, so I gave out some misinformation earlier. So far it's been hard finding ways to calculate chi-squares in an epidemiology context, but I'm trying. I'll share the correct calculations here once I find them.
Sorry for double post.

EDIT: If anyone could look at the 2017 Princeton test and figure out how they got the answer to question 7 all our problems will be solved. It'a on the test exchange. I'll link to the test and key:
https://scioly.org/tests/files/diseased ... n_test.pdf
https://scioly.org/tests/files/diseased ... on_key.pdf
For question 7, I do believe that incubation period is the correct answer I have no idea what a latency period is but whatever.
The latency period is the time between exposure and infection.
So then the answer key to question 7 is correct. What's the problem?