Design for unanticipated user behaviours

Design for unanticipated user behaviours

Human heterogeneity, device heterogeneity, diversity is the future of design. If we think through this from the onset, we can end up with something that is more flexible and scalable.

That was so kind of you GMail, I actually forgot…

One key thing I have learned the hard way in the field of user experience is having to design not only for when users do something, but also for when they do not. Usually, designers make a lot of assumptions about users’ comfort level with technology, making some design decisions turn out sour when the product hits the hands of real users.

According to a survey by,

92% of respondents checked social media on the phone in the past month, 31% stayed in the bathroom longer than necessary to finish activity on their phone

But do we take account of these scenarios during the design of our digital products? Not likely, I bet that my product manager won’t approve running a usability test in the toilet.

Even further, we design interfaces that cannot metamorphose to accommodate unforeseen circumstances. Human needs and concerns change over time, so why do we design only responsive interfaces but not responsive experiences? Why do I read my LinkedIn messages on the desktop, and yet they still show up as unread on the mobile site, and on the mobile app?

According to Eva Willis,

The future of UX is the user who begins a task on one device, continues through many more interfaces across many platforms and many more devices and completes their task with little recognition of, or interest in the complexity involved. To stay relevant in the development of digital products, we need think at a higher level than screens or sites or devices.

Before sharing some few examples of how we can anticipate for unexpected user behaviours with our digital products, it makes sense to consider general cases of how user experiences could be broken. I love the breakdown in the article Measuring Error in the User Experience which covers 4 broad causes of human errors:


These occur when users intend to perform one action, but end up doing another. For example, typing an “i” instead of an “o” counts as a slip. You can’t eliminate all those “fat finger” errors or typos but seeing a lot of slips can be a good indication to reduce required fields or data entry where possible.


These occur when a user develops a mental model (how he thinks he can achieve a goal) which is different from the product’s implementation model (appropriate way to achieve the goal). When we see users entering the wrong format in a field it’s usually a good indication that some field-hint, an auto format or some code that gracefully strips non-numeric characters might reduce these mistakes.

User Interface Problems:

Errors caused by the interface are the ones we’re most interested in as we can usually do something about these. If users continue to click on a heading that’s not clickable (mistake) or look for a product in the wrong part of the navigation then there’s probably something about the design that we can improve.

Scenario Errors:

No matter how sophisticated and realistic our usability tests are, there is some degree of artificiality to them.

So how do we design for unanticipated user behaviours?

Use Real Data During Prototyping

When working on a design project, I always try to use real content as much as possible during prototyping. When using fake content like Lorem Ipsum, the design ends up receiving a false reality of the whole, and It can be really frustrating to see our such beautiful design being broken in production.

When we design with real data, we make more informed design decisions, knowing fully well the constraints and edge cases that could likely break our design during implementation. This makes us take further considerations into how we build our layouts, navigations, modules and interaction patterns.

Examples of real life scenario could be unanticipated character lengths of some values e.g first names, last names, usernames e.t.c

When lengths of strings f*ck up?

One should be immediately skeptical of presentations that lack adequate sourcing or presentations that contain only tendentious or highly selected, cherry-picked sources. — Edward Tufte

By running design tests with a range of real-life data, we can uncover usability issues that would have been concealed by a narrower set of representative fake data. Two tools I highly recommend for this are Framer and Invision Craft plugin for Sketch.

Consider Internalization

We have more than 7 billion people on the planet, and just about that many computing devices. Given this scale and diversity, interface design can’t be approached with a one-size-fits-all model. If your product is to be used across different countries, there are some design considerations you can make to appeal to global audiences.

Often when we think about laying out a user interface for English users, contents are are read left to right, top to bottom. However, there are over 500 million speakers of languages that go right to left instead, and in this case, it’s much more natural to start in the top right and go down to the lower left. The most popular of these languages are Arabic, Urdu, Hebrew, e.t.c.

A good rule of thumb is to test your UI’s in German first, if it is one of your languages, because it tends to be longer than other western languages.

Twitter Like Button in German
Design for Blank States, Maximum States

What happens if my inbox is full?

Does the system auto-delete messages for me or alerts me on how to do this myself? Or even better does the system do a better job of informing me when I am close to getting to such phase and provide me actionable workarounds?

In the example below, Microsoft Outlook complains that you have hit the maximum file size allowed for upload, but the error message isn’t very explanatory for a basic user on what to do next. The only available option is to click “OK I’m frustrated” or “OK I will use GMail” or “OK, I will google what a shared location means”

Microsoft Outlook | GMail Maximum File Attached Use Case

On the other hand, GMail does a better job of providing what the exact maximum file size is, and simultaneously providing an alternative for such scenario. You can then decide to “Cancel, I have a file of 24MB”, or “Cancel, I will give the video to the recipient via a flash drive”, or you can just proceed with the alternative without cancelling.

What happens on a virgin interface?

When there is little or no data, the user feels like they are in a virgin land. It then becomes our job as designers to show simple tutorials or make the next step seemingly obvious, as this will guide their expectations and not feel like they are in an unfamiliar territory.

I particularly love the screen Evernote shows when you first create an account as a new user.

Evernote Blank State for new users

If we start our design process with a deep consideration of multiple scenarios, it turns out to be a lot less work on the long run. Even though it’s a little more work upfront, it totally pays on the long haul, because it lets you think through where you need the flexibility as you’re designing.

This article originally appeared on UX Collective

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