Disease Detectives B/C

[kjhsscioly]

A crossword puzzle? How many questions long was your test? My regionals test was super long, with several graphing problems, where you had to calculate all the points on the graph. AND they told us we weren't allowed to take the test apart.

[Starapollo1]

Our regional test was amazing! Before we took it the test writers introduced themselves and explained their background. There was a man who a professional epidemiologist, a woman who worked in a microbe lab but used to be an epidemiologist, and then a woman who was a microbiologist! The test was the best disease test I've ever seen! It was like 80 questions, with two cases, graphs, etc. It was intense but awesome!!

[GoNerdHerd]

What region are you in? (I only ask because I'm thinking of doing this event next year, and reading comprehension is one of my strengths.) I'm Region 8.

Awesome- I'm in Region 8 too! What school are you from? Also this year on the region 8 test there was a crossword puzzle that was worth like a third of the points on the test(it might have been a tiebreaker though, I don't remember). We got like 80% of the crossword but there were of a couple weird things like medical terms that we didn't know.

I'm from Simpson, you?

The other problem I see with this event is that the test could be anything. Look at the Test Exchange, the types of questions vary quite a bit between tests...

[havenguy]

There are also a lot of different types of tests. It seems like most tests I have taken are vocab-based. Then there are 1 or 2 tests that were all tables and graphs, and some tests that are multiple choice with a lot of statistics. I am just trying to take as many tests as I can to prepare myself for everything.

[kjhsscioly]

most of the tests are a combination thereof, and all the tests I have seen have been fairly long.

[Kevlar]

There's quite a lot you can be tested in for this event. I thought I had everything down (everything from the ever-helpful wiki and some notes from a Div C competitor) until they skipped most specific questions on food-borne illness and asked us on time-related issues (probability of events over time) and to compute using a chi-square test. (the latter was toturously time consuming)

[prelude to death]

Yes, I agree with you Kevlar, having also taken the same test myself. Although, I have to say that you did better than me.... >.< (And we lost your team by one point, if the results turn out to be official.)

I felt like at Regionals, my partner and I didn't really focus that much on food-borne illnesses, so thye put on like, 10 questions about food-borne illnesses on there. And then, at State, we updated the cheat sheet and expanded some of the information on there to include food-borne illnesses, so of course, they ask us to compute using chi-squares and to answer questions about vaccines and viral and bacterial infections, right? (I have the worst luck ever....)

There was also a question I was unsure of: If a highly contagious disease breaks out amongst a population, and the population is pretty big, so one person = less than 1%, then 0% of the population will be infected if t = 0. Draw the shape of the graph for when t = 100. When t = 100, 100% of the population will be infected. Assume that the disease is incurable until t = 100, so once you get the disease, you cannot be cured of it until t = 100.(Hint: The line/graph will not be linear.)

Or, the question might have been less vague. It was somewhat like that. So, does anyone else know what the shape of the graph should roughly look like? (Kevlar, tell me if I missed any details.)

[Kevlar]

That what I remember, and I think it was 1 out of a 1000 people at the start. I'm pretty certain the graph goes up exponentially and stops somewhere in between and stays constant until t=100. At regionals, the matching the source with the pathogen was what got us. (we ended up 4th) At state, the vaccine part was easy, but I'm not sure how in-depth the answer needed to be. It was probably the time-related questions that did us in. My coach isn't sure if the info they told us about the chi-square value was accurate. But the, there was that question if we could trust our statistical analysis or something, which I put no, since the chi-square results contradicted what I calculated for OR. Should've done RR as well.

[prelude to death]

Okies... I'll have to trust your judgement on that.... my partner and I placed 8th... >.> <.< >.<

[rkoopma2]

Yes, I agree with you Kevlar, having also taken the same test myself. Although, I have to say that you did better than me.... >.< (And we lost your team by one point, if the results turn out to be official.)

I felt like at Regionals, my partner and I didn't really focus that much on food-borne illnesses, so thye put on like, 10 questions about food-borne illnesses on there. And then, at State, we updated the cheat sheet and expanded some of the information on there to include food-borne illnesses, so of course, they ask us to compute using chi-squares and to answer questions about vaccines and viral and bacterial infections, right? (I have the worst luck ever....)

There was also a question I was unsure of: If a highly contagious disease breaks out amongst a population, and the population is pretty big, so one person = less than 1%, then 0% of the population will be infected if t = 0. Draw the shape of the graph for when t = 100. When t = 100, 100% of the population will be infected. Assume that the disease is incurable until t = 100, so once you get the disease, you cannot be cured of it until t = 100.(Hint: The line/graph will not be linear.)

Or, the question might have been less vague. It was somewhat like that. So, does anyone else know what the shape of the graph should roughly look like? (Kevlar, tell me if I missed any details.)

wouldn't it be like an exponential curve until you start running out of susceptible hosts and it the curve would slow, running close to 100% for a while, until t=100

also, what are chi-squares? can you direct me to a website about them or something?
Thanks!