Table 6 Set of heuristics for expert inspection

H1

Visibility of system status

a. Always keep users informed about what is going on (e.g. “loading”, “deleted”)

b. Provide appropriate feedback (e.g. tactile, visual, audible) to the user within reasonable time

H2

User control and freedom in system navigation

a. Provide “emergency exits” to instantly leave an unwanted state

b. Provide basic navigation controls on screen, even if the device itself provide buttons to perform similar functions (e.g. “back” function)

c. Avoid accidental activation of closely located touch controls

H3

Consistency and standards

a. Users should be able to do things in a familiar, standard and consistent way, based on experience from similar apps and platforms (e.g. tactile gestures)

H4

Realistic error management

b. Express error in plain language (no codes) and constructively suggest a solution

c. Users should be warned to confirm risky action in order to avoid accidental errors (e.g. delete, payment)

H5

Minimize the user’s memory load

a. Provide clear affordance for touch controls and other UI elements

b. User should not have to remember information between screens

H6

Customization and shortcuts

a. Make the system easy for first time setting and learning

b. Provide basic configuration options for common users and advanced configuration for expert users

c. Provide shortcuts to most frequent tasks, allow users to tailor frequent actions.

H7

Aesthetic and minimalist design

a. Avoid displaying irrelevant or rarely needed information

b. Most relevant information should be highlighted through large size, color, etc.

H8

Physical interaction and ergonomics

a. Touch control elements should have adequate size and spacing for fat fingers

b. Place control elements in a recognizable position

c. Place control elements so they can be easily pressed with the user’s thumb in any hand (or provide an option for switching layout based on hand orientation)

H9

Minimize human-device interaction

a. Strive to reduce interaction effort because users may be in motion with only one-thumb and one-eye on the system

b. Reduce data entry, especially with typing. Use sensors (e.g. location, voice) or historical and personalization data to establish defaults

H10

Readability and Glanceability

a. Ensure that text and textboxes fit on the screen

b. Ensure readability in different lighting conditions with sufficient contrast

c. Ensure user is able to quickly get relevant information by glancing at screen