Friday, 13 November 2015

Using Show Me without using Show Me

At The Information Lab we are rather lucky to have so many certified Tableau trainers. This means that we get the chance to teach either complete newbies the FUNdamentals of Tableau or how to leverage some of the more advanced features of Tableau very often as there are not that many trainers out there. We also get the chance to teach each other so much that we won’t otherwise come across. Why is this important you rightly ask? Read on…

This week I the chance to teach some very bright analysts how to make the most of their skills with Tableau. Whilst teaching the attendees about the Marks Card through a technique that I call ‘Whiteboard Tableau’ (more on this soon), one attendee Natasha corrected me about the way to create a Stacked Bar chart without using the Show Me panel.

Normally I would say add your discrete field (blue pill) that you want to be your bars on to the Column or Row shelf (depending on whether you want a vertical or horizontal bar chart respectively) and add the measure (green pill to the opposite Shelf you placed the discrete pill. To create a stacked bar chart you can then drop what you are dividing each of those bars by on to the Colour Shelf of the Marks Card. Easy.

But I heard… “Just drag the new discrete field on to the bars and it colours the chart”. I froze, not wanting to say “No Tableau doesn’t work that way” as I have learnt you never say that as someone has always found a way. Despite using Tableau heavily for the last three years, I never had come across this technique before. I got Natasha to talk me through the technique and it worked a treat.


I posted it on Twitter and got eight favourites and a retweet. The tweet even got a reply from my favourite English Zen in America:
Most people I have showed didn’t even know of this technique until I showed this guy:

(note the ‘guy’ in question is that clever one on the right not that other floppy haired fella on the left)

For those who haven’t come across Robin. I’m sorry. The man is a Tableau legend and always knows a trick or two to get you round that surreal blending issue or why that Table Calc won’t add itself to your Filter Shelf.

Robin instinctively knew the solution, “well, Tableau’s using Show Me”. Uhh? No, it’s not? I’m dropping it in to the view. Robin has an amazing teaching patience and didn’t call me the imbecile that I deserved to be regarded as. Watch the gif closely as the mouse reaches the View, it changes to have the Show Me logo pop-up.

What Tableau is doing here is using the Show Me logic that decides what is the best way to visualise the data you have selected. What I would have expected Tableau to do is treat this drag-and-drop in the same way that it would if you would double click this new discrete field (in the gif example ‘Category’). I would expect Category to be added to the right of Region (the discrete value dictating the bars). But no, Show Me is assessing that the best way to visualise this data when dropping this new discrete pill in to the view is to use it on colour.

How else can you make use of this?
Well understanding what Tableau is going to do in certain situations is key so the table below details what else happens when the Show Me logo pops up as you drag something in to the view

Starting Point
Type of new pill
Result
Basic bar – one discrete pill on columns and one continuous pill on rows
Discrete
Stacked bar – new pill used as colour
Basic bar – one discrete pill on columns and one continuous pill on rows
Continuous
Shaded bar chart – new pill used as colour as well but as it is continuous the colour is a scale rather than categorised
Basic Line Chart – Date on Columns, Continuous pill on rows
Discrete
Depends – if there are less than 20 Discrete Values then Table picks colour, if there are more then it just add the new field to Detail and created multiple lines
Basic Line Chart – Date on Columns, Continuous pill on rows
Continuous
Colours the existing line by the new data field
Part to Whole Chart (Treemap, Packed Bubble or Pie Chart)
Discrete
Creates additional rows using the new data field but retains the marks type
Part to Whole Chart (Treemap, Packed Bubble or Pie Chart)
Continuous
Creates additional rows retaining the marks type also but uses Measure Names and Measure Values to form the new rows

So next time you use Tableau, go a little slower and see what Tableau is doing is you might uncover something that you think is normal behaviour but isn’t, it could lead you to other time savings!  

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