Sparkline Tickers—What would Tufte think?
I was recently informed by the folks at Bissantz and Company, makers of the product SparkMaker, that they have added the ability to display sparklines as tickers in the new version of the product. They asked for my opinion of this new feature. While watching their examples crawl across the screen, I couldn’t help but think that Edward Tufte, the inventor of sparklines, might not be pleased by this expression of his idea. I certainly cannot speak for him, nor do I wish, in expressing my own opinion, to suppress any views to the contrary that any of you reading this blog might wish to express.
Sparklines can work wonderfully in various contexts, including dashboards, to communicate rich trend information very simply and in a small amount of space. Think of them as an enhanced, much more informative substitute for the trend arrows that often appear on dashboards. Tickers are information displays that usually occupy a strip of horizontal space on a screen, just tall enough to show a single line of text. Information in tickers is constantly changing as it crawls across the screen from right to left, eventually disappearing at the left edge of the ticker, but constantly being replaced by fresh information that crawls in from the right. Here’s an example of a sparkline ticker display that appears on Bissantz’s website:
Here’s another example, truer in design to Tufte’s original, which crawled across the bottom of the screen as I read about SparkMaker Tickers:
What’s missing from this static display that you’re now viewing, of course, is the movement of the sparklines across the screen. They never stand still.
Movement in our field of vision is something that grabs our attention powerfully. It is difficult to ignore objects that move across the screen. There are occasions when the use of movement to demand people’s attention might be appropriate, including on dashboards, but the only examples that come to mind involve urgent information, which viewers must not fail to notice.
Here’s the rationale that Bissantz gives for sparkline tickers, which I’ve extracted from their email to me and their website (emphasis is mine):
Tickers show numerical data in a most compact way. In an endless loop an arbitrary number of values is passed before the eye of the onlooker, without any need for user interaction. The marquee consumes little space and leaves plenty of room for other or additional displays. The presentation within the marquee is clear enough to allow for perfect readability. Yet it lets the user stay with whatever she does.
SparkTicker’s information density releaves [sic] the user: He is not forced into heavy parameterization, page turning or query execution. Instead, he may remain focused on understanding and interpreting his data.
We…believe that dynamic displays of information can enhance data visualization in a lot of environments. For this purpose we provide a ticker option: SparkMaker users who want to go beyond static displays of sparklines can use the built-in ticker feature. It exports selected sparklines to an HTML ticker which can be easily integrated into any web publication. We are confident that such dynamic presentations can help to raise awareness for data and data visualization in surroundings that are typically reporting-averse. Since information in a sparklined ticker is distributed in a non-intrusive way and uses only a small portion of a screen’s real estate, people grasp information as a side-effect while e.g. browsing in the Intranet of their company.
The question we must ask about this and any form of information display is, “Does it work?†Are there any circumstances in which a ticker display of sparklines would communicate information more effectively than all other means of display? Although I am open to the possibility, I honestly cannot think of any.
You certainly wouldn’t want to user sparkline tickers routinely on a dashboard. The constant motion would be too distracting. Also, if the information contained in the ticker is not important enough to display on the dashboard, all at the same time, why not put it on a separate screen and make it easy to access when needed. A display of all the sparklines together would allow comparisons to be made that are not supported by a ticker display.
Let’s consider some of the specific claims that Bissantz is making about sparkline tickers. Is it true that “dynamic displays of information can enhance data visualization†and that sparkline tickers distribute data in a “non-intrusive way� As I stated earlier, movement might be useful at times to grab a viewer’s attention to some new information that is urgent. There are also times when motion is necessary to provide a meaningful picture of information that itself involves change or motion. Hans Rosling and his colleagues at gapminder.org use motion to show change through time in a way that actually makes sense and brings information alive for people. The movement of data in tickers, however, doesn’t fall into this category. And please don’t confuse dynamic displays with dynamic data. The information that is contained in these sparkline tickers comes from static Excel spreadsheets. It is not dynamic.
Do sparkline tickers provide an extraordinary degree of “information density� They appear to do just the opposite. You can see very little at a time and what you see reveals itself slowly as each sparkline plods onto the screen. When sparklines are genuinely used to create dense information displays, such as a screen or page full of them, that’s when they shine.
Do sparkline tickers allow someone “remain focused on understanding and interpreting his data� Wouldn’t a display that stands still do this better?
Will they “help to raise awareness for data and data visualization in surroundings that are typically reporting-averse� I’m not convinced that this is the kind of exposure that will present data visualization favorably and inform people of its true benefits.
Do sparkline tickers enable people to “grasp information as a side-effect while…browsing…the Intranet of their company� Nothing that I’ve seen in the research about information perception and comprehension suggests that this would happen. This claim is somewhat akin to the old mistaken notions about subliminal advertising, which supposedly sent consumers running to the store by air brushing words such as “sex†and “buy me†onto ice cubes in a form so subtle that only the unconscious mind could detect them. I must admit, it would be nice if we could grasp information as a side effect based on some peripheral form of display while attending to other things, but I doubt this is possible, and am fairly certain that if it is, sparkline tickers are not the ticket.
If you would like to add your opinions and insights to this discussion, please do so by responding to this blog. I am always open to evidence that I haven’t considered, even if it proves me wrong.