Usability Is King For Your Product. Here’s How We Can Finally Measure It

Businesses live and die by the usability of their services, writes Continuum’s Rick McMullen. But how do they know when there’s a serious problem?

Usability Is King For Your Product. Here’s How We Can Finally Measure It

“Life used to be simpler,” my mom says while making her fourth attempt to update her Windows firmware in order to install Office 2011 on top of Office 2008.


I don’t correct her, but I don’t believe her either. As far as I can tell, life has always been complicated; and certainly as long as my mother has been alive, there has been incredibly sophisticated technology in the world. (When she was my age, people were landing on the moon. Nothing simple about it.) What I do believe, though, is that life used to be more usable. What’s different now is that complex technology has become so freakin’ cheap that it seems free to include “one more” feature in your product. The unforeseen cost, of course, is that those extra features hurt usability.

But we know all this. There is plenty of literature on the subject, and good usability is table stakes for a modern product. If your product isn’t usable, your business is in a dangerous position. Maybe you can get by in the short term by boasting your killer feature set; but the fact is that if people can’t figure out how to use your bells and whistles, you’re going to feel it on your bottom line sooner or later.

It may be old news, or even obvious to some, that poor usability can hurt customer relationships and hold back sales. But what isn’t obvious to business leaders is: How do I tell if it’s happening to me?

Before I get right to answering that, consider customer service for a moment. The adage “the customer is always right” has been uttered many times, in many languages, for many years. Long before the cash register was even invented, businesspeople intuitively knew that cultivating relationships with loyal customers was key to long-term success. Yet still, even in 2012, there is no end of companies who find ways to pull short-term profits out of their customers, at the expense of the longer-term customer relationship. (Example: So-called free three-month magazine subscriptions that you have to remember to opt out of before you get automatically charged.)

As the service economy continues to evolve, more and more companies are working to measure and improve their customer-service performance as a key indicator of success. And to this end, a minor revolution occurred in 2003, when the corporate world was introduced to Net Promoter Scores (NPS). In only a few years, NPS had become far and away the leading measure of customer loyalty.

Here’s the beautiful thing about NPS: Organizations get results from the data, but it’s amazingly simple to collect. You simply ask your customers, on a scale of 1 to 10, how likely they are to recommend your company/product to their friends and colleagues. People who give high marks are “promoters,” (i.e., will recommend you) people who rate low are “detractors,” (i.e., will bad-mouth you), and in the middle are “passives” (i.e., don’t care enough to do either one). The theory, which has been backed up by evidence, is that companies who have more promoters than detractors (i.e., a high Net Promoter Score) will win. They will acquire more customers and make more money.


Critics of the metric say it is a blunt instrument, and maybe it is. But if your NPS is -20, and your biggest competitor’s is 80, you had better do something about it. It could certainly be argued there are better ways to measure customer loyalty; but the success of the Net Promoter Score was closely tied to being the most usable way to measure customer loyalty. This is all by way of saying that even one of the oldest goals in the business world–to keep the customer happy–has only recently been armed with a really useful, usable metric.

Now, back to usability. I suspect that even if you believe wholeheartedly in the power of usability, you probably aren’t measuring it in a useful way and making it a key part of your business strategy. I am willing to bet that one of the major reasons people don’t effectively measure usability is that they don’t know how. One of the other major reasons is that the established usability metrics take a lot of effort and analysis to get anything out of them, so ironically, the usability measurements themselves aren’t terribly usable. So here’s my thought. Let’s apply the broader lessons of the Net Promoter Score to usability. No complicated metrics, no long surveys, just one “ultimate question for usability” that lets us know if we need to invest more in making our products intuitive.

What, then, should that question be? When I was in college, we were taught that the quantitative measures of usability are efficiency (how long a task takes), effectiveness (whether or not a subject can complete a particular task), subjective satisfaction (whether or not the experience is enjoyable), and error rate (how many times the subject makes a mistake, even if they eventually complete the task). All good stuff to know, but too low level for this purpose.

The famed usability expert and evangelist Jakob Nielsen says that quantitative measures of usability are low bang for the buck; he favors qualitative evaluation instead. When it comes to making a product better, I also firmly advocate qual over quant. But qualitative evaluation is just too much work to answer the simple question, “How do I know if I need to invest in usability?” I asked all of my “usability guru” friends, dug into the existing metrics, and came up with some of my own ideas; and the one I came across that most succinctly captured it was “How confident are you using this system/product/service?”

Unfortunately for me, this wasn’t one of my original ideas. It is a question I poached from the System Usability Scale (aka the “SUS”), originally published by John Brooke at Digital Equipment Corporation in 1986. It’s actually a nice survey in and of itself, but it takes several minutes to complete and doesn’t overtly tie to business goals, and I’ve never actually seen it done. Put another way, it’s usable but not usable enough to actually ever get used.

I settled on that notion of self-reported confidence, because it captures two important factors from both a human and business perspective. First, technology is supposed to work for people, and not the other way around. Second, as my uncle Fred once told me, “The worst thing you can do to an adult is make them feel stupid.”


In our modern world of automated interactions, the usability of your product or service is an important part of your relationship with your customers, and it had better not suck. If people knew that the complexity of their products was causing serious brand damage, they would surely make the investment to prevent it. But by no fault of their own, people outside of the design and usability world just don’t necessarily know when there is a problem. So even if this one question is under-nuanced, over-generalized, and does not tell you how to fix your usability issue, it does answer the question, “Do I have a problem I need to address?” with a yes or no.

So I propose that we all ask one simple question of as many potential users of our products as we can. The question I asked above was “On a scale of 1 to 10, how confident do you feel using this system?” But in truth, the question itself is less important than making sure you ask it. It’s a well-understood quirk of human nature that we tend not to take things seriously unless we’re measuring them. Whatever you ask, pay attention to the percentage of scores that are under 7. Those are all the customers you’ll lose, customers you’ll keep without delighting, or customers you’ll perennially frustrate, and for an embarrassingly fixable reason. It’s easy to do, and it might just move us toward a more usable world, which I know my mom would appreciate.

[Images: urfin, Olga Danylenko, and Triff via Shutterstock]