What's the best way to graph results of a matrix ranking question?
I'm reworking an existing module which graphs results from a live survey with several different question types. I discovered that the results of matrix-type ranking questions are graphed as a single pie chart (apparently representing the proportion of first-rank votes for each item, ignoring the rest of the data).
Considering different ways of representing these data in a more complete way, I considered generating a multiple column chart, either side-by-side or stacked. While I decided on stacked, I'm somewhat torn between grouping the data by item or by rank. Here's an example data set I concocted (n = 3):
For tajmo, codeinthehole, Sure! Here's (a new) mock data table used to generate all of the charts (which have been re-done) showing number of votes received for each element:
Talented Workers Fun Task Reasonable Deadline First 2 1 0 Second 1 1 1 Third 0 1 2
In this mock example, three participants vote to rank (by a ordering a series of draggable rows) their 'factors to corporate success' from among: having a talented workforce, having fun tasks to accomplish and being given reasonable deadlines. In this example, 2 people ranked "having talented workers" as their first choice, while no people ranked "having a reasonable deadline" as their first choice.
I have re-made the three graphs with this new data set (which is why they differ from previous versions of this question).
As I mention above, the first version of this module presented only the pie chart, showing the proportion of first-rank votes each item received.
I am tasked simply with "providing more information, probably in the form of bar charts" from these data.
My question centred around the best way to display this "more information". Since I chose to use a stacked bar chart, I'm left with the problem of grouping: is it conventional to group the data into:
- Bars of rank segmenting them by item; or
- Bars of item, segmenting by rank.
Grouped by item
Grouped by rank
The original first-rank pie chart was presumably implemented to focus attention on the proportion of votes cast for highest-ranked item. While there is a desire to provide more complete information, that original idea is still relevant. I believe the second graph, grouping by rank, best shows this trend.
What do you all think? Should I even consider a different graph type?
(While the possibility exists that the survey designer may provide a nearly unlimited number of items, they are practically limited to 6.)
As per dnbrv's request, here's a mock-up of what the current pie chart would look like. I believe the previously implemented charting function was done quickly, which is why it's functionality is limited, and not that they simply only care about the top ranked item. As in the first data set, this chart only plots the number of first-rank votes each item received (in a population of 3).
I imagined the answer to the question would be rather straightforward, which is why I didn't bother including the data table (especially as it's mock data anyway) or going into great detail about the surveying procedure. I hope these additions, and more clearly-labelled charts will help.
@dnbrv Done. Please note that these are mock-ups, since I don't have the ability to publish actual data sets (as they are private and not mine). Sorry for the limitation!
I can't make heads or tails of your data as it is. Could you show us what the survey looks like?
I'm assuming that each respondent can has a certain number of 'votes' that they can distribute between a set of answers according to their strength of preference. Is this correct?
I just made significant modifications to the question, and re-generated a new, clearer data set (provided) which I hope will improve the question. Thanks for your comments.
Thanks for the update. I needed to understand the data collection methodology in order to know what you were really trying to represent. I posted my answer below. I strongly recommend against the sort of bar graph you have because it obscures the relative size of things when they don't appear side-by-side.
The fundamental question to answer is "what is the rank of choices?" The secondary question is "how were these ranked?". And it sounds like your primary task is to show meaningful information, while and your secondary task is to provide context with data.
To answer the first question, you need to actually rank the results; that is implied in the title (although not explicit), but I don't see overall rank in any examples. Assign point values, like "1st = 2pts, 2nd = 1pt, and 3rd = 0pts. That yields an actual rank and scoring as follows:
- Talented Workers (5)
- Fun Task (3)
- Reasonable Deadline (1)
That right there is pretty meaningful and easy to understand. You could call it a day at this point, but you still need to provide context.
How were votes distributed? Show the ratio. Since the number of people voting (a scalar value) is universal to each answer, you do not need to include it in each data point: just say it once at the top or bottom. If the vote distribution is simple enough or doesn't need to be precise, I recommend sparklines. If you need to provide more context or precision, a rollover popup can do that.
Drawing 1: details
In this case the rank is obvious, you don't need to include numbers. (Avoid chart junk by leaving out any extraneous information.)
Note that methodology is just a link, since it's relevant to only a subset of users. I recommend making that a rollover popup if it's short copy.
Drawing 2: bird's eye view
This illustrates a larger set of results and how they might look with the ranking numbers included, and longer sparklines to represent more data points.
I love this answer tajmo! You've provided me with not only a wealth of information but a lot to think about for future projects. (I'm still getting my feet wet with real UX design and spend a lot of time reading this forum; this was my first question.) Thank you! PS. I've checked out your other posts on prototyping and sketching, I think I might pass by Staples and pick up some Sharpies on the way home ;)
Nice to know I have recruited a new sketcher! If you deal with information design a lot, I recommend the one-day workshop with Edward Tufte. It's pricey, but you get a whole library of his books. That really shaped how I think about stats reporting and the usefulness of data.