back to Overview

Simple & precise – improving the Bolus Calculator with your help

February 23, 2017 by Matthias Gieselmann

mySugr Bolus Calculator recommends meal and/or correction insulin doses (note: currently approved for use in Europe only). It takes into account your current blood sugar, any insulin on board from recent injections, your settings, and your carb entry (if any) in order to help by suggesting an appropriate dose of insulin for your specific situation.

Unfortunately, a few months after launching the first version of the bolus calculator module, we realized that some users were experiencing difficulties completing the setup (and proper setup is critical for the bolus calculator). Analysis of our support requests and statistics revealed we were losing users at each step of the setup process – users we could have been helping many times every day!

Data assessment: why are we losing users?

Why? What now? And you

The best thing about working at mySugr is that diabetes experts, programmers, and designers work in close cooperation. That means we put our heads together to look at possible improvements. As a designer, you are my most important source of information. I ask mySugr users to try our designs in usability tests and observe the outcome. Only after significant iterations and improvements does anything make it into the app. That’s how, with your help, we continually improve the mySugr app step-by-step. Is it time-consuming? Truthfully? Yes. But it’s also definitely worth it.

For version 2.1 of the bolus calculator module we applied the following principles:

Principle 1: clear language

It’s like the old joke: Do you know what dihydrogen monoxide is? Water! Simple things sometimes have really complicated names, especially among experts. Diabetes is no exception.

Not enough text – too much text – perfect amount of text!

Example: in the old bolus calculator, we asked users for their carb factors without properly explaining what carb factors are. The reaction? Mainly helpless shoulder shrugging. So in the next concept, we asked:

“To calculate the right amount of insulin, the Bolus Calculator needs to know how many units of insulin you need to cover one Exchange.”

That still wasn’t clear to everyone. We struggled to figure out the best way to ask the question. Finally, we managed to be more precise:

“How much insulin to you usually inject for 1 Exchange?”

Nearly everyone can answer that!

Principle 2: clarity wins over smooth and slick

In the old bolus calculator, it was possible to specify time periods for some settings:

mySugr Bolus Calculator's old scroll wheel design

This approach seemed practical because all the time periods could be represented in a few lines and it all fit into a neat card deck design. Instead, it turned out to be problematic because not every user understood how to create time periods, insert them retrospectively or change them.

Now we use standard entry fields that feel familiar from other apps. We’ve replaced freely selectable time periods with an entry field for each half-hour in the day. It may be less attractive, but it’s certainly more clear.

Bonus: A glance at the statistics showed that most users only use one value for the entire day. So we initially only show one entry field. However, users who need to can expand the time entry fields.

Redesign of EN mySugr Bolus Calculator Carb Ratios screen

That brings us to the next point:

Principle 3: only reveal the important stuff

Imagine the farmer’s market of your dreams. If you’re interested in the origin of the produce, you would ask the farmer where it came from.

Scribble Schlachter

But wouldn’t it be weird if the farmer, unprompted, and while weighing and packing away each item, started to recite the origin and backstory of each product? Well, we think the same goes for good user interfaces. Trust is built when information is available but that doesn’t mean that everything should be visible all the time. It’s enough for it to be available. This is where our info button comes in handy: we use it to hide information about the bolus calculation details that aren’t always necessary or interesting, but they are available when desired.

A screenshot showing how we expand details when desired

In technical jargon, this principle is called “progressive disclosure,” or, put differently, “only show the complicated stuff when necessary.”

The bottom line

Those are 3 quick examples of how design changes helped improve the mySugr Bolus Calculator module. By using best practices and usability tests, we’ve made it dramatically easier to use. Early results show positive results and more people are enjoying the bolus calculator than ever before. It seems to be making a big difference for our users – and that’s what really counts.

Thanks for your continued support!


Diabetes App

Do something good for your diabetes with mySugr

mySugr makes diabetes suck less – during crazy adventures or even just a normal workday.

Newsletters, blog posts and tips & tricks from the monster workshop.