Hmm, it's quite possible you know more about statistics than me, but...
Usually equations for calculating confidence level are based on the
assumption of a random sample, not a volunteering self-selected sample.
If you have a self-selected sample, then the equations for "how likely
is this to be a fluke" are only accurate if your self-selected sample is
representative; and there aren't really any equations that can tell you
how likely your self-selected sample is to be representative, it depends
on the circumstances (which is why for the statistical equations to be
completely valid, you need a random sample).
Is my understanding.
On 12/5/2012 2:18 PM, Rosalyn Metz wrote:
> I totally get what you're saying, I thought of all of that too, but
> according to everything I was reading through, the likelihood that the
> survey's results are a fluke is extremely low. Its actually the reason I
> put information in the write up about the sample size (378), population
> size (2,250), response rate (16.8%), confidence level (95%), and confidence
> interval (+/- 4.6%).
> On Wed, Dec 5, 2012 at 1:52 PM, Ross Singer <[log in to unmask]> wrote:
>> Thanks, Rosalyn for setting this up and compiling the results!
>> While it doesn't change my default position, "yes we need more diversity
>> among Code4lib presenters!", I'm not sure, statistically speaking, that you
>> can draw the conclusions you have based on the sample size, especially
>> given the survey's topic (note, I am not saying that women aren't
>> underrepresented in the Code4lib program).
>> If 83% of the mailing didn't respond, we simply know nothing about their
>> demographics. They could be 95% male, they could be 99% female, we have no
>> idea. I think it is safe to say that the breakdown of the 16% is probably
>> biased towards females simply given the subject matter and the dialogue
>> that surrounded it. We simply cannot project that the mailing list is
>> 57/42 from this, I don't think.
>> What is interesting, however, is that the number roughly corresponds to
>> the number of seats in the conference. I think it would be interesting to
>> see how this compares to the gender breakdown at the conference.
>> This doesn't diminish how awesome it is that you put this together,
>> though. Thanks, again to you and Karen!
>> On Dec 5, 2012, at 1:28 PM, Rosalyn Metz <[log in to unmask]> wrote:
>>> Hi Friends,
>>> I put together the data and a summary for the gender survey. Now that
>>> conference and hotel registration has subsided, it's a perfect time for
>>> to kick back and read through.
>>> [Code4Lib] Gender Survey
>>> Gender Survey Data is the raw data for the survey. Not very interesting,
>>> but you can use it to view my Pivot Tables and charts.
>>> [Code4Lib] Gender Survey
>>> Gender Survey Summary is easy to read version of the above -- its the
>>> summary I wrote about the results. Included is a brief intro, charts
>>> above), and a summary of the results.
>>> Let the discussion begin,
>>> P.S. Much thanks to Karen Coyle for reviewing the summary for me before I
>>> sent it out. Also if there are any typos or grammar mistakes, please
>>> my friend Abigail who behaved as my editor.