Requirement 3

Figure has a blue and white background with a screen drawing in the center and two bubbles one showing a thumb up and another one with an eye which represent
“vision”

Must be able to communicate results to users

 RequirementSpecification

3
Device must be able to communicate results to users.Screen size: 4in x 7inText: 18pt size, screen: 4in x 7inFont Type Courier (serif, monospaced)
JustificationTarget users are unable to differentiate between colors 
Self-interpretation
Research surveys show that these are the most ideal fonts and sizes for elderly individuals in terms of readability and reading speed. 

Verification: Confirm that the output is the correct information 

 Validation: Surveying elderly and vision impaired individuals on user interface