• ability can change in time
• can change temporarily
• just as ability changes over the course of life, it can change during the day due to contextual variables and surrounding conditions
• technologies that are now mainstream were once helping with accessibility (e.g. SMS helped people with hearing disabilities)

DIX — disability-interaction types

• Permanent — e.g. wheelchair
• Situational — e.g. noisy environment
• Temporary — e.g. injury recovery