Answer:
The user experience or the user activities
Step-by-step explanation:
One concern that must be considered when designing usable interactive products apart from the points raised here is that the user experience and the activities the user will be doing when they are interacting with the products must also be considered. For instance, a user who is having a drink in one hand and the usable interactive product requires involving both hands or both thumbs then it can be a problem unless the product can be used with any two fingers of any hand.