2 Replies Latest reply on Sep 17, 2012 7:01 PM by Steve Haroz

# Standard error by category

My data has the following columns:

• X - numerical dimension (integers 1-5)
• Y - numerical measure
• User - text dimension (Adam, Beth, Chris, Dan)

There are multiple rows of data for each combination of X and User. Plotting a line of the average Y along X is simple enough.

What I need to show is the average and standard error across individual user averages.

1. Find the average Y for each X for each User. (avg for Adam, avg for Beth...)
2. Find the standard error between these User-averages.
3. Plot the average for each across users (the average of the averages) where the thickness (reference band?) is the avg +/- the std error.

Could any one offer advice on how to accomplish this in Tableau?

Edit: clarified 3.

• ###### 1. Re: Standard error by category

Hi Steve,

When the measure is placed on the view, the aggregation can be changed. Right click on it and select Measure-->Average. Another instance of the measure can be placed on the view, and to find the Standard Deviation, right click and select Measure-->Ste. Dev.

Then, a calculated field can be created to find the +/- on the std error.

Hope this helps!

-Tracy

• ###### 2. Re: Standard error by category

Hi Tracy,

Sorry I wasn't clear in the original message. The line I want to plot is the average of the averages.

For each user, take the average. Then find the standard deviation and average of those averages.

I understand how to create a calculated field, but I can't figure out what to put to make the average and standard deviation of the user averages.

Thanks,

Steve