The theme of alternative chart types continued with Lorna setting this challenge to create a jittered bar chart. We needed to use the same fake survey data set used in week 4, so initially some data remodelling was required. I’ve already blogged that here, so please refer to the modelling the data section if you need help.

The questions all need to be grouped based on the text that preceded the question, so I created

Question Group

TRIM( SPLIT( [Question], “-“, 1 ) )

which split off the text in front of the first ‘-‘. I actually created this by right-clicking on the Question field > Transform > Custom Split and selecting to to split off the first 1 column using the – separator.

I also created a field to number the responses

Response No

CASE [Response]
WHEN ‘Strongly Disagree’ THEN 1
WHEN ‘Disagree’ THEN 2
WHEN ‘Neutral’ THEn 3
WHEN ‘Agree’ THEN 4
ELSE 5
END

Once I’d done that I was able to ratify the numbers by building a simple table with Response No and Response on Columns, Question Group on Rows, and CNT(Id) on Text.

Eyeballing these numbers against where the ‘bars’ in Lorna’s viz stopped and I figured that was on the right track. However then I wasn’t particularly sure what to do next.

Lorna’s instructions were very brief. I figured I’d need to use a jitter (ie RANDOM()) somewhere, and as I’d need to add Id to the Detail shelf at some point, to generate 1 dot per respondent, I deduced I’d also need

Total Respondents

{FIXED [Response], [Question Group]:COUNT([Id])}

Adding this into by table above and I got the same values as CNT(Id) which is what I expected.

After scratching my head a bit, I decided that Lorna was possibly being vague, as there was probably help ‘out there’. So I googled, and immediately stumbled upon this very useful blog post, which pointed me in the right direction for the additional calculations required.

I created

Columns

RANDOM()

Jitter

RANDOM()

note – due to the way RANDOM() works, Jitter and Columns won’t contain the same value.

Rows

[Jitter] * [Total Respondents]

And with these I could build out the viz

Add Response No, Response and Columns to Columns. Change Columns to be a dimension.

Add Question Group and Rows to Rows. Change Rows to be a dimension. Add Id to Detail.

Change the mark type to circle, reduce the size and add Question Group to Colour and adjust accordingly.

Finally add Question to Tooltip and adjust the tooltip. Then remove all gridlines, hide the Columns axis, change the title of the Rows axis, and remove the row and column titles (hide field labels for rows / columns).

A pretty short blog today! My published viz is here.

Happy vizzin’!

Donna