Archive for the ‘blogging’ Category
Nice to get featured at Painters table, the magazine of the painting blogosphere.
It is a wonderful site, pulling together lots that is going on at painting blogs worldwide, so it can be seen all in one place. It is easy to get lost in that blogosphere, following the links could serve as a full time avocation.
Here’s a run chart showing the visits to my blog in May (I know, it would be nice to have more visits).
It shows at a glance just how much variation there is in the system visits per day to my site: although the average (mean) number of visits per day for May was 58, the highest number of visits was 144, and the least was 17.
Plotting the data in a control chart or capability chart (invented by Walter Shewhart and used by W. Edwards Deming) shows that the system is out of statistical control, in that there is special cause variation on day 29,
and the run of twelve days below the mean may also suggest special causes of variation (a run of six or more might be an indication of a special cause).
With special causes it could be meaningful to ask “what happened, specifically?”
Answers: 1) On day 29, I used a poll for the first time, and as it was researching a suggestion made by my son (that some people need help to see optical effects), both my sons were happy to encourage their Facebook friends to visit my site and complete the poll. As a result I got more visitors than usual that day. 2) On days 10 to 21, I may have been less active than usual in looking at other blogs as I was away for some of those days.
All the other data points show common cause variation: the variation that can be expected by the normal behaviour of the system. The chart shows that I could expect to get anywhere between 0 visits (the Lower Control Limit, LCL) and 112 visits (the Upper Control Limit, UCL) on any one day. To be surprised by data points within these limits, to get concerned for example at the 17 visits, would be foolish. To improve performance when the system shows common cause variation one must focus on the common causes rather than on individual data points. I could ask myself “what happens predictably every day, that causes this variation?” I would answer that I post something including a visual image, and that I take a few minutes to look at other blogs, mostly by tag surfing. To get more visits I would have to change this system.