i) System designers may think for various input operations using mouse click or drag and drop file objects, Camera to click photo etc.

ii) Designers may have assumed that end user knows everything about system and understand all necessary actions required to use the system.

iii) Developers may deliver only targeted task of system and may overlook some important functions required for system design that may cause the failure and usability of the system.

iv) General errors by developers assumptions about the end user

• End user knows everything.
• Understanding about complex operations.
• End users behavior may be ignored.

v) If system designer overlooks end users skills and knowledge, it leads to poor system design.