Illustrated guide to Excel Services Chart Rendering

October 4, 2010

 
COMMON QUESTION:
  “Hey, will this chart render unchanged in Excel Services, or will it look different?”

MY STOCK ANSWER:  “Hmm, I forget, let’s try it out”

I hate giving that answer.  So today, I ran a little test.  Simple workbook, 12 charts that are all flavors of fancy.  Not an exhaustive test, but a reasonable sample.  Here are the 12 charts in Excel client (desktop).  Click for a larger version.

Client2 
12 Charts in Desktop Excel

Green Circle = Renders 100% identical in Excel Services
Red X = Renders less than 100% identical (sometimes small differences, sometimes large)

Now, here are the same 12 charts rendered in Excel Services:

ECS
Same 12 Charts, As Displayed on SharePoint (Excel Services)

Again, note that being flagged with an X isn’t the kiss of death – I just didn’t want to bog down in “grading” the differences.  Sometimes the changes are big (top left chart) and sometimes the changes are astoundingly small (bottom middle chart).

Either way, having an illustrated reference is going to be helpful for us, so I thought I’d share it.  Feel free to submit questions/comments/other examples.  I may expand this reference over time.


More on visualization

January 10, 2010

I know some of you have been following this topic closely, so I thought I’d point out another article.  This time, visualizations seen in the media are redesigned by members of the community to be clearer and more informative:

http://visualizeit.wordpress.com/2010/01/08/redesigned-visualizations/

It’s a little bit ironic, of course, that I had to stare at that post for awhile before figuring out what I had to do in order to see the redesigned graphic :)

But I would take these as examples of the chart police doing good, thoughtful work.  And the examples they are dissecting are just laugh-out-loud funny.


More discussion on gauges

January 4, 2010

Continuing the theme from the “chart police” post, more discussion on gauges/speedometers/dials over on the Dashboard Zone site:

Dashboard Zone 

Consensus from discussion around the chart police post seemed to be that these sorts of thing really ARE pretty gimmicky, and that there are better ways to get attention AND convey data.  I think I mostly agree, but I never say never :)

Been busy with the FAQ site over the weekend and today.  Tomorrow, I have to choose which PowerPivot topic to dive back into.  So much to choose from, my OneNote overfloweth! :)


The death of pie charts?

December 23, 2009

“The customer is always right”

-Anyone who knows their business

A business intelligence feud!

A few weeks back, a BI analyst posted a list of factors to consider when selecting a new BI tool.  Shortly thereafter, a BI blogger posted a scathing critique of that article.  The analyst, for his part, then blasted the blogger on Twitter (and curiously, re-linked the blogger’s offending post).  By BI community standards, this is a feud of uncommon proportions.

I don’t really want to get in the middle of such an entertaining exchange, but I feel compelled to offer at least a short comment.

You see, the analyst had the audacity to suggest that the number of visualization types (charts, gauges, etc.) supported by a BI tool is an important factor for potential customers to consider.  Perhaps he was unaware of the newly prevailing wisdom:  fancy visualizations are bad for you.  Simpler is better, 3d is a distraction, pie charts are passé,  and gauges/stoplights are toys.

I think that point of view is at least partially misguided, and while rooted in scientific fact, it misses something fundamental about human psychology.

The prevailing wisdom of the chart police – three examples

1) Use Bar Charts Instead of Pie Charts

Three Color Bar Chart Pie Chart

Simplest Visual Comparison

Same Numbers, Harder to Compare

There is research proving humans are good at judging the relative lengths of objects, but bad at comparing the relative sizes of areas.  (Although I’d submit that, in college, my friends and I were masterful estimators of pizza subdivision, so perhaps the human race as a whole is just out of practice).

2) Avoid 3d and Other Effects

…because again, they just make visual comparisons tougher.

3d Bar Chart Pretty Bar Chart

Not Acceptable

Probably Earns You a Lecture

  Basic Bar Chart  
 

Boring Yes, But Efficient

 

3) Gauges and Stoplights are Just Plain Silly

KpiGauge200Up  Stoplights Modified

…and apparently animated bubble charts have also come under fire lately.

Is Your World Frictionless?  Mine either.

Remember in physics class, how we were often instructed to ignore the effects of friction and/or air resistance?  That was helpful, in an instructive way – we learned useful principles.  But you can’t apply those in the real world without factoring friction back in.

A similar thing is happening here.  And the friction that’s being ignored in this case is the human attention span.

Before someone can begin breaking down and interpreting a chart or other visualization, they must first decide that it’s something worth paying attention to.

powerpivot icon And most people love eye candy.  They just do.  It’s fun to look at cool pictures, and fun draws people in.  For example, some of my friends worried about the 3d chart appearance of the icon I chose to use for my site.  “It runs counter to the prevailing advice about charts” was the concern.  (You might notice that the PowerPivot field list never creates 3d charts – discretion is the better part of valor, even in software).

But when I took a vote amongst my friends and colleagues, this icon was the overwhelming favorite, with more than 2/3 of the respondents selecting it as their first choice.  It was not well-liked by the other 1/3, however, who happened to be the people I already regarded as the pickiest people I know :)

Show Some Restraint, but Always Play to your Audience

Here’s what I now believe:  the Chart Police are loud and influential, and they have good information to share, but they do NOT represent a broad cross-section of the public.

Wisdom dictates that you give your audience what they are most likely to engage with.  So, if your report audience is mostly normal people, feel free to spice things up a bit.  Don’t overdo it to the point that the original point is obscured, but make it fun.  Make it attractive.  Because your message won’t mean a thing if they don’t engage with it first.

If you know your VP likes their reports to contain pie charts, or 3d charts, or even animated bubble charts, by all means, deliver them.  Don’t feel like you have to re-educate everyone about the sins of these things.

Of course, if your audience a bunch of college professors or professional graphic designers, I recommend following the chart police guidelines closely, because they very well might think you an amateur if you do not.

This isn’t a question of right or wrong, really.  You just want your message to have the highest uptake possible.

Personally, I’d love to see studies that measured both the accuracy of the information conveyed by various visualizations, combined with the level of audience engagement.  I really do think the Chart Police are onto something, but I think the story is unfinished as it stands.

Further Reading

I generally think of Edward Tufte when I think of the chart police.  I’m not at all certain that he is the source of the venom that I see on the topic, though – I tend to think that he just identified some things that had previously been ignored, and then people who read about that picked up torches and pitchforks.  Regardless, he does fantastic work, and notably is also an artist.  Browsing his site is definitely a good use of time.

I also thoroughly enjoyed Eye Candy is a Critical Business Requirement.

Back Next Week

I’m visiting relatives in Chicago right now and don’t have access to my PowerPivot machines.  So this was a good opportunity to cover this chart topic that’s been on back burner for weeks.  Next week though, I’m moving ahead with DAX, might be finishing (!) the Great Football Project, and I have a couple of other reference topics about PowerPivot that I’d like to start compiling.

See you then!