jon.recoil.org

Module Note_brr_kit.Human

Human factors.

System latency feelings

These values are from here.

noticed is 0.1s, the time span after which the user will notice a delay and feel that the system is not reacting instantaneously.

val interrupted : Note_brr_kit.Time.span

interrupted is 1.s, the time span after which the user will feel interrupted and feedback from the system is needed.

left is 10.s, the time span after which the user will switch to another task and feedback indicating when the system expects to respond is needed.

val feel : unit -> [ `Interacting | `Interrupted | `Left ] Note.signal

feel () is a signal that varies according to user latency constants:

  • [user_feel ()]t = `Interacting if t < User.interrupted.
  • [user_feel ()]t = `Interrupted if t < User.left.
  • [user_feel ()]t = `Left if t >= User.left.

Touch target and finger sizes

These values are from here.

val touch_target_size : float

touch_target_size is 9.mm, the recommended touch target size in millimiters.

val touch_target_size_min : float

touch_size_min is 7.mm, the minimal touch target size in millimeters.

val touch_target_pad : float

touch_target_pad is 2.mm, the minimum padding size in millimeters between two touch targets.

val average_finger_width : float

average_finger_width is 11.mm, the average adult finger width.