On Fri, Oct 21, 2011 at 2:48 AM, Bjoern Hoehrmann derhoermi@gmx.net wrote:
- Andreas K. wrote:
The median and quartiles are on page 7 of the report:
---o0o---
Valid responses were received from respondents between 10 – 85 years. Overall, the average age of the Wikipedians that participated in the
survey
is 25.22 years. Half of the respondents are younger than 22 years. The
most
frequent age that can be observed within the respondents is 18 years. Splitting the respondents in four equally large age groups shows
that
25% are younger than 18 years old, 25% are between 18 and 22, a further
25%
are between 22 and 30 (e.g. half of the respondents are between 18 and 30 years) and the remaining 25% are between 30 and 85 years old. There is a slight age difference between readers and contributors - readers are, on average, 24.79 years old while contributors show an average age of 26.14 years. Finally, female respondents are younger (23.79 years) than male
ones
(25.69 years).
---o0o---
You made a point about editorial judgement and age, so I looked at data on editor age. As far as I can tell, the above only mentions the average age of "contributors", it does not say "The median age of contributors is 30 years" or some such thing.
The quoted text says that "half of the respondents are younger than 22 years". This is the same as saying that "the median age of respondents was below 22 years of age", because that's how the median is defined.
The average age of contributors was higher than the average age of respondents (readers + contributors) overall, but the difference was very minor (1.35 years). So the median age of contributors wouldn't have differed much either.
For the relative position of mode, median and average in a right-skewed distribution see http://en.wikipedia.org/wiki/File:Comparison_mean_median_mode.svg -- the median is always smaller than the average.
Best, Andreas