[R] Linear Logistic Regression - Understanding the output (and possibly the test to use!)

[Frank Harrell]

On Sun, 5 Sep 2010, stats at wittongilbert.free-online.co.uk wrote:

> David Winsemius wrote:
>>>
>>> 1. is glm the right thing to use before I waste my time
>>
>> Yes, but if your outcome variable is binomial then the family argument
>> should be .... "binomial". (And if you thought it should be poisson,
>> then why below did you use gaussian???
> Used gaussian below because it was the example from the docs.  Thats not
> my data, its example data which was not binomial.
>
>>>
>>> and 2. how do I interpret the result!
>>
>> Result? What result? I do see any description of your data, nor any code.
> I didn't provide MY DATA because I thought that would complicate things
> even further.  So I was hoping for some advice on how to interpret the
> result of the example data so that I could then apply that to my data.
> I haven't even tried to run my data as I couldn't see what the output of
> the examples was trying to tell me.
>
> However, as you've snipped it because it was not relevant thats useful
> to know.  I often find this problem with the examples in the R doc's
> they suddenly take a dataset that I have no knowledege of and play with
> it and produce an 'answer'.  The examples are presumably provided to
> enable me to work through how the code works etc.  So what I was hoping
> for was someone to point to somewhere on-line that documents how to use
> the function for logistic regression and to explain what all that table
> of data it spits out actually meant.  Someone has VERY KINDLY posted me
> something off list which I believe helps.
>>
>> I think you need to consult a statistician or someone who has taken
>> the time to read that "statistical mumbo jumbo" you don't want to
>> learn. This mailing list is not set up to be a tutorial site.
> I have access to stats advice, but I don't (a) want to turn up to them
> with a pile of paper from R and them say glm() may be the wrong
> analaysis (b) they don't do R so they can't tell me if I've used R
> wrongly and (c) I completely expect they'd say which of the values in
> the table matter since no paper I've ever seen published showed a
> logistic regression with a table of numbers.

Clearly the time to consult a statistician is before you have done any 
statistical analysis.

Frank Harrell

>>
>> I have a couple of Kleinbaum's (et al) other texts and find them to be
>> well written and reasoned, so I suspect the citation above would be as
>> accessible as any.
>>
> Thank you, that is useful.  There is a real problem when buying R text
> books.  None of the bookshops round here stock any which means you can't
> tell if they are much good.  I've looked at some and they seem to be
> re-writes of the help files.