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Re: st: RE: simulation: finding the winner, and generating unique values
From
Michael McCulloch <[email protected]>
To
"[email protected]" <[email protected]>
Subject
Re: st: RE: simulation: finding the winner, and generating unique values
Date
Sat, 25 May 2013 08:10:26 -0700
Thank you Kieran,
What you suggest is exactly what I intended. This is a simulation based on an educational testing project, in which a sequence of questions (denoted by variable A), are posed to five volunteers (denoted by variable B) in sequence (hence needing 1-5 for each level of A). And, they will each get the question correct, or not (hence 0 or 1 for C). What you suggest is perfect!
I have two other questions on which to ask your coding advice:
1. The sequence in which volunteers answer the question varies. Thus, I wish to randomly assign the sort order of 1-5, within each level of A.
2. Each volunteer will encounter many questions within a day's work, and I wish to test whether being the first to address a question has an effect on success. Thus, I wish to count, (and test if possible) the total number of correct answers each volunteer gets in a day's work, and whether who goes first (or second, and so on...) influences performance.
Any further advice would be much appreciated, as I appreciate what you've already suggested.
Best wishes,
Michael McCulloch
--
Pine Street Foundation, since 1989
124 Pine Street | San Anselmo | California | 94960-2674
P: (415) 407-1357 | F: (206) 338-2391 | http://www.PineStreetFoundation.org
On May 24, 2013, at 8:40 PM, Kieran McCaul <[email protected]> wrote:
> ...
>
> I'm not quite sure what the intent of the simulation is.
>
> 1. How can I simulate B so that only unique values of 1-5 are created?
>
> I don't understand what you mean here, particularly given that the code you use is under a comment "* simulate variable: B (values 1-5 sampled without replacement) ".
>
> There are 20 observations, 5 per level of "a". The only way that "b" can be assigned the values 1 to 5 without replacement is by assigning them within "a".
>
> I don't think this is what you are trying to do, but if it is, the following will do that:
>
>
> clear
> set seed 12358
> * simulate A
> set obs 20
>
> gen byte a = mod(_n,4) + 1
>
> sort a
> by a:gen byte b=_n
>
> gen byte c = uniform()>=0.5
>
>
>
>
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf Of Michael McCulloch
> Sent: Saturday, 25 May 2013 3:31 AM
> To: [email protected]
> Subject: st: simulation: finding the winner, and generating unique values
>
> Greetings!
>
> * I have three questions related to the following data simulation.
> * 1. How can I simulate B so that only unique values of 1-5 are created?
> * 2. Is there a more elegant way to code simulation of variable B?
> * 3. How can I identify which variable B had the highest total count of C, within levels of A?
>
> clear
> set seed 12358
> * simulate A
> set obs 20 //create 20 observations
> gen a=1 in 1/5
> replace a=2 in 6/10
> replace a=3 in 11/15
> replace a=4 in 16/20
>
> * simulate variable: B (values 1-5 sampled without replacement) gen b=.
> replace b=(1 + int(5*runiform())) if a==1
> replace b=(1 + int(5*runiform())) if a==2
> replace b=(1 + int(5*runiform())) if a==3
> replace b=(1 + int(5*runiform())) if a==4
>
> * simulate variable: C
> gen c1=uniform() //Generate n (equal chance of 0-1)
> gen c=.
> replace c=0 if c1<0.5
> replace c=1 if c1>=0.5
> drop c1
> list, noobs
>
>
>
> Best wishes,
> Michael McCulloch, LAc MPH PhD
>
> --
> Pine Street Foundation, since 1989
> 124 Pine Street | San Anselmo | California | 94960-2674
> P: (415) 407-1357 | F: (206) 338-2391 | http://www.PineStreetFoundation.org
>
>
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