Left Handedness and Mobile User Experience

An inconvenience experiment

A girl with manicured nails tapping a phone screen
Photo by Rob Hampson on Unsplash

It’s no secret that the world has always favoured right-handed users over left-handed users when it comes to product design. Whether it’s a mobile app or something as simple as a writing desk, left-handed users have always lamented the fact that they are usually an afterthought.

According to UX design experts, usability patterns, finger and thumb patterns change when it comes to right or left-handed use (Cornelia, 2014). Below is a representation extracted from heat maps that indicates the surface area covered by left and right-handed use.

A heat map of mobile screens showing left and right handed zones of use
Babu, 2019

As is evident from the above image (Babu, 2019), the safest zone for ambidextrous use is seemingly the bottom centre area. Even then, the coverage is not 100% similar.

In addition to the surface area coverage, we can also see that the angle of the swipe also differs. If we look at a classic home screen. Below is an image of the author’s current phone. For posterity’s sake, the device is a Samsung S10 and the dimensions of the screen are 149.9 x 70.4 x 7.8mm (Samsung, 2019). The author is predominantly right-handed.

Anatomy of a Samsung S10 home screen showing interactive elements.

Consider the same image with an overlay of the above handedness overlays. We can see how icon and screen reach work in relation to handedness.

Heat Map of both left & right handed use overlayed on S10 screens

In this report, we will be testing Instagram against left-handed and right-handed use. In one instance, Instagram will be recorded and used by a user whose dominant hand is the right one and then a user whose dominant hand is the left.

Why Instagram?

The objective of this report was to test an app that was not only a daily social usage app but one which encompassed visuals, video and text prompting varying degrees and types of on-screen interaction. For example, such a test on YouTube or Netflix would not suffice since there are limited points of interactions with large intervals in between depending on the length of video that users choose to consume.

The Daily Use Test

Two users, one left-handed and another right-handed will be asked to perform a series of actions on Instagram.

  • Vertical scrolling (homepage or otherwise)
  • Double Tap
  • Press & Hold
  • Swipe left
  • Swipe Right
  • Typing

The Four Corner Test

This is what a typical Instagram home page looks like.

Image showing placement of icons on the four corners of an Instagram screen

On the top left are stories where you can tap your profile picture to access them, the top right is where you can access your messages, The bottom left is the home page button and the bottom right is the main profile page of the user. The four corner test is a simple tapping test to see whether the user, left and right-handed is able to tap that button without shifting their hand and whether the button responds on the first tap.

Observations

When it comes to right-handed use, Instagram is fairly easy to operate. Scrolling is rather straightforward as is scrolling horizontally through an album. Tapping the search button to go to the ‘Explore’ page is also right within the angle of reach.

Double tapping, of course, is the simplest task while swiping left and right are also fairly simple. Typing while awkward isn’t terribly difficult either with the classic QWERTY keyboard on the screen.

When it comes to left-handed use, the difference in usage is not overtly dramatic. The interface is designed to be central to the screen allowing for easy use when it comes to the bulk of things. Double tapping, swiping and press & hold are also fairly simple actions. Typing however is difficult and there was a need to shift to both hands. When using the left hand, the user had to be very careful of not making accidental palm touches as they are usually prone to do.

Four corner test

When it comes to the four corner test, the right-handed user was able to reach the bottom right and left corner icons fairly easily while top left was a little tricky followed by the top right.

For the left-handed user, reaching the bottom two corners was also fairly easy with a little difficulty reaching the top right and a little more difficulty in reaching the top left.

For a fairer assessment, one must consider how often these four corners will be of use during a standard Instagram interaction. The home button (bottom left) will be of the least use since it’s the default page not requiring use until the user has moved to another. The bottom right is of the second least use since content creation tools are in the centre and the user does not need to go to the profile other than to browse their own content. The top left is the most used corner to view and create stories with the top-right being the second most used with personal messages. Messages can also be accessed by swiping left on the home screen. It’s interesting to note that the top left corner which has the most use on the home screen is also the most difficult to reach by left-handed users. Also, the least used button (home button) is also placed on the left. It must be noted however that these observations are entirely subjective.

Instagram Poll

In addition to the above experiment, a fairly simple poll was put up to ask users whether or not they had difficulty using Instagram as left-handed individuals. Out of 73 viewers, only 15 responded with 7 votes for left and 9 votes for right.

Image of three screens showing an Instagram poll and results
Please don’t shame my sample size, I know it’s small.

Out of the seven left-handed respondents, 3 provided further comment. One user was ambidextrous but did mention that while they use their left hand for various activities, they resort to the left when using the app and smartphones in general. One left-handed user mentioned that they had never felt any difficulty in using the app and the third left-handed user mentioned that they had to make a conscious effort to adapt and use the app with their right hand in order to make the most of the experience.

Image showing responses of individuals that are ambidextrous or left handed.

So far, this test has only taken into consideration on-screen tapping, swiping and typing functions but has not yet taken the physical model of the phone into account. Taking the phone used throughout this experiment as an example. While home buttons have come and gone and camera placement and bezels have moved around with annual updates, two things have for the most part remained the same. The placement of volume buttons and the lock screen button. Below is a representation of what a standard iPhone and android phone look like.

A comparison of the hardware anatomy and button placement of an iPhone and Samsung

For a right-handed user, the lock screen button usually hits right at the length where the thumb would rest whereas the volume buttons are comfortably in the reach of the forefinger and middle finger.

For left-handed users, however, the volume buttons rest beneath the thumb and the lock screen button is where the forefinger rests.

On android, the volume keys rest higher than the lock screen key whereas the iPhone has both keys on the same height. Based on comfort levels and reach for left-handed users, one can say the iPhone is slightly more comfortable for ambidextrous or left-handed use.

Conclusion

When it comes to Instagram, we can perhaps confidently say that it is for the most part inclusive for left and right-handed use. With most major functions central to the design of the interface, the discomfort is minor and for the most part easily adaptable without much discomfort.

References

Babu, R. (2019). Inclusivity guide: usability design for left handedness 101. UXDesign. Accessed 18th December, 2019. Available at < https://uxdesign.cc/inclusivity-guide-usability-design-for-left-handedness-101-2bc0265ae21e&gt;

Cornelia, (2014). Do users interact with their mobile devices with their dominant hand? Realites Paralleles. Accessed 18th December, 2019. Available at < https://realites-paralleles.com/2014/02/do-users-interact-with-their-mobile-devices-with-their-dominant-hand/&gt;

Hoober, S. (2013). How Do Users Really Hold Mobile Devices? UX Matters. Accessed 18th December, 2019. Available at < https://www.uxmatters.com/mt/archives/2013/02/how-do-users-really-hold-mobile-devices.php&gt;

Samsung, 2019. Galaxy S10 Specifications. Accessed 18th December, 2019. Available at < https://www.samsung.com/global/galaxy/galaxy-s10/specs/&gt;

Ullinger, M. (2018). Design for Lefties. Medium. Accessed 18th December, 2019. Available at < https://medium.com/nyc-design/design-for-lefties-854fa5826bbe&gt;

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