Recently, I received an email from a fellow name Mark Ostroff who has written a guide to designing “accessible” content using the Oracle Business Intelligence Suite (OBIEE). In particular, the guide addresses issues regarding impaired vision, such as colorblindness and total blindness. Despite the fact that Mark began by saying that he and I “could be ‘twins separated at birth’ in our orientation about business intelligence,” by the second email in our conversation it became clear that he had a bone to pick. He accused me of shirking my responsibility by not teaching people to design information displays in ways that are accessible to the blind—dashboards in particular. Actually, his accusation was a bit harsher. He suggested that, by failing to teach people to design dashboards in ways that were accessible to the blind, I was encouraging my clients to break the law. Mark’s bold accusation prompted me to write about this issue.
I’ll begin by stating my fundamental position: a dashboard that is accessible to the blind is a contradiction in terms. “A dashboard is a visual display of the most important information needed to achieve one or more objectives, consolidated and arranged on a single screen so the information can be monitored at a glance” (Few, 2005). No forms of data visualization, not just dashboards jam-packed with graphics, can be made fully accessible to someone who is blind. I am not insensitive to the needs of people who are visually or otherwise impaired. I am merely pointing out what anyone who understands data visualization knows: no channel of perception other than vision can fully duplicate the contents of graphs. Similarly, what someone can communicate through the audio channel in the form of music cannot be fully expressed visually. If it could, why bother performing or recording music? Why not just distribute the written score? Vision is unique in its abilities to inform and enable thinking. Those who lack vision can develop their other senses to compensate to an amazing degree, but never in a way that fully duplicates the visual experience.
The information that is displayed in a dashboard can and should be presented to people who are blind in a different form when needed. Despite Mark’s bold challenge, current laws regarding accessibility require some organizations—mostly government—to provide the information contained in something like a dashboard in a way that is accessible to the blind, not necessarily to make the dashboard itself accessible. Unfortunately, an alternative form of presentation will not convey all of the information contained in a well-designed dashboard and it won’t communicate the information as efficiently, but if someone who is blind needs the information, it behooves us to provide a reasonable, even if imperfect, alternative. The alternative, however, will not be a dashboard. By definition, a dashboard is a visual display, because the visual channel provides the richest and most efficient means of presenting information for monitoring purposes, which no other channel can match—not even close. If airlines were required by law to provide flight-phobic customers with an earthbound form of transportation, that alternative would be called a train or a bus, not an airplane. In like manner, a means of monitoring that uses braille or a screen reader as its medium should not be called a dashboard. There’s enough confusion about the term already. Let’s not muddy it further.
When quantitative information is presented graphically, it offers the following advantages over written or spoken words and numbers:
- Patterns in the values are revealed
- Series of values (e.g., 12 months worth of sales revenues) are chunked together into visual objects (e.g., a line in a line graph), which makes it possible for us to see the entire series at once and compare it to other entire series of values, thus augmenting the capacity of working memory
- Much more information can be presented in the limited space that’s available on the page or screen
- The visual cortex processes the graphical information in parallel and more efficiently than the slower, sequential process that’s required for language processing
Data visualization is not only useful, it is finally being recognized as essential. It’s hard to imagine how any other channel of perception will ever be able to provide viable alternatives for these advantages of vision. It certainly isn’t possible to come close to doing this now.
I support the Americans with Disabilities Act (ADA). The ADA became law to prevent discrimination against people with disabilities. It does not, however, heal disabilities. It cannot give sight to the blind. It can require that organizations remove roadblocks to equal rights for those with disabilities and accommodate them in reasonable ways, but it should never try to equalize the playing field between those with sight and those without by forcing those with sight to wear blindfolds. Unfortunately, some efforts to expand accessibility venture into this territory, and I find that intolerable.
Mark seems to believe that all dashboards should be designed so that every bit of information is accessible to a screen reader to accommodate the needs of those without sight. To do this, a great deal of information would have to be added to dashboards and much of it would have to be expressed in inferior ways to make the contents of a dashboard accessible to a screen reader. Despite Mark’s good intention, this would result in dashboards unworthy of the name. The experience of those with sight would be unnecessarily compromised to a costly degree. I say unnecessarily, because the needs of the blind would be better served by a separate display that was designed specifically for a screen reader without compromising the design of the original dashboard. This approach, rather than the way that Mark advocates, would result in less time, effort, and cost. We should approach accessibility intelligently. What might work for a general purpose website might not work for a dashboard. One size definitely does not fit all.
It was hard for me to imagine what Mark had in mind as an accessible dashboard, so I downloaded his guide to take a look. I quickly learned that his idea of a dashboard is quite different from anything that I would qualify as such. Here’s an illustration from the guide:
What he calls a dashboard looks a lot like an online report with a couple of tables on it. A few graphs do appear in the guide, and Mark suggests that they should be made accessible to those who are colorblind in the following manner:
That’s right—according to the guide, crosshatching should be used in addition to colors. Crosshatching can create an annoying shimmering effect known as moiré vibration. This affects people who are colorblind as much as anyone. What this recommendation fails to take into account is the fact that people who are colorblind can see color (except for extremely rare cases of complete color blindness), they just can’t discriminate particular colors, primarily red and green. Avoiding combinations of colors that those who are colorblind cannot discriminate solves the problem without resorting to the scourge of crosshatching.
Despite a search, I failed to find anything in the accessibility guide that explained how information contained in graphs (i.e., images) and thus inaccessible to screen readers could be communicated to those without sight. Text descriptions can be attached to a graph that can be accessed by screen readers, but those descriptions would not contain any information about the values in the graph. Apparently, a dashboard that is accessible to the blind would need to eliminate graphics altogether. As I said before, the result would not be a dashboard. When accessibility to information in dashboards is needed by those who are blind, it currently works best to give them an alternative that displays text and tables of values formatted for easy accessibility by screen readers. A table, even though it information, such as patterns of change and the means of comparing entire series of values, but no automated presentation of the data that isn’t visual could achieve that. At best, someone could write a description of the patterns and summarize the story contained in the graph with words, but that would require human intervention, which cannot be automated—at least not yet.
We should be concerned about accessibility to information, not only for those with disabilities. Good design makes information accessible. It is a sad fact of life, however, that everything cannot be made equally accessible to everyone. People differ in ability and experience. Accessibility is achieved by understanding these differences and designing communications in a way takes them into account. Accessibility is not achieved by slighting one audience in an attempt to meet the needs of another. So far, the business intelligence (BI) industry in general has not taken even the shared needs of humans into account, let alone the unique needs of particular groups. I’m not surprised that Oracle’s attempt to accommodate the needs of the visually impaired fails to exhibit thoughtful design. Oracle’s approach to accessibility so far is simpleminded, and certainly is not worthy of the name “business intelligence.”