
1. Re: Error bars
. HealthMaps Aug 5, 2008 7:33 PM (in response to Brad Langhorst)Please add some error bar (confidence interval) capability. I would imagine that business and finance folks would want at least a highlowclose chart for tracking stock prices.
There is the capability to set as an aggregation option, the variance. Which means that for some measures (the mean?) confidence intervals would be possible. Being able to see the confidence intervals is really a very important part of analysis. Tableau allows slicing and dicing data which is incredibly useful, but then the next step of being able to do a little inference would be a big help.
But beyond that one needs the capacity to use their own calculated confidence intervals and display them.
They are needed for trend plots and for bar charts.

2. Re: Error bars
guest contributor Nov 10, 2008 9:41 AM (in response to Brad Langhorst)I fully support this idea.

3. Re: Error bars
Alex Blakemore Nov 10, 2008 3:18 PM (in response to Brad Langhorst)You can do some of this now
See http://www.tableaucustomerconference.com/sessions/training/
And then look at the workbook for the class called
Means, Modes, Percentiles & Outliers: Using Tableau to Understand Distributional Data
Check out the worksheet titled "Modern Box Plot"
This example uses reference lines to show quartiles, but you could just as easily choose to show confidence intervals instead.
This is not to say that Tableau couldn't improve its support for displaying confidence intervals. It takes a bit of a trick to get this chart to work (placing one dimension on the column shelf twice)
But note one really nice feature. By plotting points with semitransparent marks, you can get a very good impression of the distribution of the data, definitely better than you get from a traditional box plot.

4. Re: Error bars
. Jesus Apr 16, 2009 11:55 AM (in response to Brad Langhorst)In a Research setting, the use of error bars is standard; you don't need to explain anything, you view the graphs, and that's it: Visualization at its best. Please consider adding this feature to future versions of Tableau.

5. Re: Error bars
. fmalter Jan 28, 2010 1:59 PM (in response to Brad Langhorst)I can't find the workbook in the link Alex Blakemore provided. How can I add simple error bars to points in a line graph? Thx.