Defining thumb reach envelopes for handheld devices

Our objective is to provide thumb reach envelopes to help guide the placement of controls on handheld devices and to provide useful methods to gather and analyze thumb reach data.

With the proliferation of handheld, interactive devices, such as cameras, mobile phones, game systems, and remote controls, human factors professionals involved in designing these products need data to help guide the placement of controls. Previous studies have not provided adequate two-dimensional thumb reach envelopes for the primary control surfaces of handheld devices.

A total of 90 participants in three groups (adolescent females, young mothers, and young fathers) placed representations of primary controls in preferred locations on a device model and "painted" their individual reach envelopes on a touch-screen device running a paint application.

We present two-dimensional thumb reach envelopes on the primary control surface for handheld devices. The primary reach zone for adolescent females is slightly larger and more circular than that of the adults. The preferred location for controls matches the primary thumb reach zones fairly well.

The reach envelopes presented are the first of their kind and are likely to be useful to human factors professionals. The method used to obtain the data may also be useful.

The thumb reach envelopes should be applicable to the design of many handheld, interactive devices with dimensions similar to the models used in this study. The method presented allows design teams to collect and analyze thumb reach data quickly and inexpensively for different target user populations or product dimensions.