Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread Petr PIKAL
multiple treatments, one at a time, to same pool > >>> of patients. You are correct that interactions may be important in this > >>> problem. I am only trying to help him frame the problem using an analogy. > >>> > >>> > >>> ** **

Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread Petr PIKAL
Hi I would try either some tree method (mvpart) or you can expand lm model also with users. fit<-lm(value~variable+users, data=test.m) Anyway I am not an ultimate expert in statistics. so you shall also consult some appropriate literature which can be found in CRAN web. Did you try to look i

Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread Bert Gunter
the group effect only, as originally shown >>> >>> -- Bert >>> >>> On Mon, Oct 10, 2011 at 7:43 AM, Anupam wrote: >>> >>> Groups are different treatments given to Users for your Outcome >>> (measurement) of interest. Take this

Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread gj
sers for your Outcome >> (measurement) of interest. Take this idea forward and you will have an >> answer. >> >> Anupam. >> -Original Message----- >> From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] >> On >> Behalf Of Bert Gu

Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread Anupam
, October 10, 2011 7:36 PM To: gj Cc: r-help@r-project.org Subject: Re: [R] help with statistics in R - how to measure the effect of users in groups Assuming your data are in a data frame, yourdat, as: User Group Value u1 1 !0 u2 2 5 u3 3 NA ...(etc) where Group is

Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread Bert Gunter
I should have added... If your design is not "nearly" balanced, main effects and interactions will not have any "natural" interpretation because they will be (partially) confounded. (I realize "nearly" is not a very useful characterization, but I do not know a better one, as it probably depends on

Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread Bert Gunter
Assuming your data are in a data frame, yourdat, as: User Group Value u1 1 !0 u2 2 5 u3 3 NA ...(etc) where Group is **explicitly coerced to be a factor,** then you want the User x Group interaction, obtained from lm( Value ~ Group*User,data = yourdat) Ho

Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread Carlos Ortega
Hello, In package "qualityTools" you can find one way to perform this analysis through the gageRR() function. The effect of an operator on the mesasurement system (Reproductibility) is to me equivalent to the effect you try to study of your users when they are in different groups. Regards, Carlos

Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread gj
Thanks Petr. I will try it on the real data. But that will only show that the groups are different or not. Is there any way I can test if the users are different when they are in different groups? Regards Gawesh On Mon, Oct 10, 2011 at 11:17 AM, Petr PIKAL wrote: > > > > Hi Petr, > > > > It's

Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread Petr PIKAL
> > Hi Petr, > > It's not an equation. It's my mistake; the * are meant to be field > separators for the example data. I should have just use blank spaces as > follows: > > users Group1 Group2 Group3 > u110 5N/A > u2 6 N/A 4 > u3

Re: [R] help with statistics in R - how to measure the effect of users in groups

2011-10-10 Thread gj
Hi Petr, It's not an equation. It's my mistake; the * are meant to be field separators for the example data. I should have just use blank spaces as follows: users Group1 Group2 Group3 u110 5N/A u2 6 N/A 4 u3 5 2

[R] help with statistics in R - how to measure the effect of users in groups

2011-10-09 Thread gj
Hi, I'm a newbie to R. My knowledge of statistics is mostly self-taught. My problem is how to measure the effect of users in groups. I can calculate a particular attribute for a user in a group. But my hypothesis is that the user's attribute is not independent of each other and that the user's att