Re: Presenting results of categorical data?

2001-08-16 Thread Thom Baguley
Robert J. MacG. Dawson wrote: Oh, it never is (strictly), outside of a few industrial applications. Nobody ever took a random equal-probability sample from all turnips, all cancer patients, all batches of stainless steel, all white mice, or all squirrels. However, there are good

Re: Presenting results of categorical data?

2001-08-16 Thread Robert J. MacG. Dawson
Thom Baguley wrote: however, I think the defence of convenience samples can be stronger than this. Unless we have reason to believe that a sample is biased in such a way as to generate our pattern of results a convenience sample is just as

Re: Presenting results of categorical data?

2001-08-16 Thread Dennis Roberts
At 12:39 PM 8/16/01 +0100, Thom Baguley wrote: For example, if a new drug is administered to a treatment group made up of serious cases and compared to a control group of mild cases obtaining more cures for the treatment group might be considered better evidence than a random sample. Thom

Re: Presenting results of categorical data?

2001-08-16 Thread Thom Baguley
Dennis Roberts wrote: sorry ... i can't agree with this ... it could be that in the serious cases ... there is a unidentifiable gene factor that INTERACTS with the treatment ... that is not available in the mild cases group (that's why you have serious and mild cases) ... so, it is not

Re: Presenting results of categorical data?

2001-08-15 Thread Donald Burrill
On 14 Aug 2001, Nolan Madson wrote: I have a data set of answers to questions on employee performance. The answers available are: Exceeded Expectations Met Expectations Did Not Meet Expectations The answers can be assigned weights [that is, scores -- DFB] of 3,2,1 (Exceeded, Met,

Re: Presenting results of categorical data?

2001-08-15 Thread Thom Baguley
Donald Burrill wrote: I agree on all of this. I'd add that at issue is whether people find the mean format useful, whether it is misleading. I'd use -1, 0 and +1, rather than 1-3. In this case the mean gives you at-a-glance summary of the extent to which the people who exceeded expectations

RE: Presenting results of categorical data?

2001-08-15 Thread Silvert, Henry
:[EMAIL PROTECTED]] Sent: Wednesday, August 15, 2001 3:34 AM To: Nolan Madson Cc: [EMAIL PROTECTED] Subject: Re: Presenting results of categorical data? On 14 Aug 2001, Nolan Madson wrote: I have a data set of answers to questions on employee performance. The answers available

Re: Presenting results of categorical data?

2001-08-15 Thread Robert J. MacG. Dawson
Silvert, Henry wrote: I would like to add that with this kind of data [three-level ordinal] we use the median instead of the average. Might I suggest that *neither* is appropriate for most purposes? In many ways, three-level ordinal data is like dichotomous data - though there are a

Re: Presenting results of categorical data?

2001-08-15 Thread Jon Cryer
I do not see how (probabilistic) inference is appropriate here at all. I assume that _all_ employees are rated. There is no sampling, random or otherwise. Jon Cryer At 11:14 AM 8/15/01 -0300, you wrote: Silvert, Henry wrote: I would like to add that with this kind of data [three-level

Re: Presenting results of categorical data?

2001-08-15 Thread Robert J. MacG. Dawson
Jon Cryer wrote: I do not see how (probabilistic) inference is appropriate here at all. Oh, it never is (strictly), outside of a few industrial applications. Nobody ever took a random equal-probability sample from all turnips, all cancer patients, all batches of stainless steel, all

RE: Presenting results of categorical data?

2001-08-15 Thread Simon, Steve, PhD
Nolan Madson writes: I have a data set of answers to questions on employee performance. The answers available are: Exceeded Expectations Met Expectations Did Not Meet Expectations The answers can be assigned weights of 3,2,1 (Exceeded, Met, Did Not Meet). One of my colleagues says that it is

Presenting results of categorical data?

2001-08-14 Thread Nolan Madson
I have a data set of answers to questions on employee performance. The answers available are: Exceeded Expectations Met Expectations Did Not Meet Expectations The answers can be assigned weights of 3,2,1 (Exceeded, Met, Did Not Meet). Our client wants to see the results averaged, so, for