Mobile Investigators: Understanding How Children Use Touchscreens

Having a background in education and having worked with children from as young as six months old, I was very interested to learn more about the challenges they face when it comes to interacting with technology.  This talk detailed research focused on children using touchscreens, which children use differently from adults and with which children face unique challenges: they have difficulties with target sizes and location, have trouble making recognizable gestures, and find dragging hard (they find it hard to maintain contact with the device throughout the dragging motion).  This makes sense when you consider that small children are still developing fine motor skills in general.

The speakers talked about their experiments aimed at trying to understand how to design technology for children's learning applications.  Their studies ask, what's difficult for kids using touch screens?  It turns out that there are three things:

• target size and location
• making accurate, recognizable gestures
• dragging: kids have difficulty maintaining contact throughout the dragging gesture

Another goal was to understand the differences between kids and adults with respect to touch/gesture input. How can we help them be more successful in their interactions with technology?

The investigators conducted three studies using two touchscreen tasks for each, with interesting results: it turns out that children not only miss hitting more targets than adults, but that they are actually almost two times as bad as adults!  Also, while the smallest targets are the most challenging for both children and adults, children still do worse in general.  Incidentally, the smallest target used was smaller than the recommended size for the android devices employed in the study, so the findings support the recommended target size guidelines for that platform.

Some other interesting findings include the results of tests for hitting targets with edge padding - the miss rates were double for these.  The researchers also found a new phenomenon called holdovers, which are touches touches in the location of previous target as the screen is changing.  Kids do this more than adults.  I wondered, does this have an impact on games with moving targets?  Or educational applications with many animations or screen redraws?  Should animations be smaller for devices/applications/features aimed at children?

Kids also tend to make gestures differently; they are bigger and have more strokes.  For example, a square gesture made by an adult is one continuous line, while a child's would have 4.  This causes kids gestures to be less recognizable, with their accuracy differing by almost 50%.  The touch cloud shown by the investigators shows misses distributed irregularly around the target; adults have a much tighter spread of touches.

One idea suggested by the authors as a mitigation for these problems was to ignore touches made by children in the same location as a previously accepted target.  Machine learning could also be used to train for kids gestures.  As next steps, the researchers will try to conduct studies with younger kids and explore in-context applications.  They would also like to try some co-design exercises with children.