A capability is what the

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object physically allows the user to do or what can be done with the object. It is the relationship between the properties of the object and the user's abilities. For example, a microscope is designed for fine studies of the microworld, but in general, contrary to the well-known phrase, it also contains the ability to hammer nails. Your expensive electric razor was created for a seemingly unambiguous use, but nothing will stop your child from using it to give the home carpet an unusual designer pattern.

Norman also identifies anti-possibility, i.e. a property that limits action. For example, a seat belt prevents you from moving and, accordingly, from being hit when the car brakes sharply.

Meaningful
If all things in the world were unambiguously readable and had only one single and immediately noticeable property, this world would probably be very logical, but extremely boring and poorly suited for development. Therefore, some objects need to be given a hint that will help to read its idea, laid down by the designers. Don Norman calls such hints signifiers. In his terminology, this is any marker or sign that makes a person behave in a certain way.

Visible features help people use products intuitively. Invisible whatsapp australia features are still there, but they need to be labeled.




Don Norman tells in the book that colleagues and friends call inconvenient and incomprehensible doors (and other things) - "Norman's doors". If on beautiful glass doors that open in an incomprehensible direction, there are no handles, no plates, no other clues that indicate their method and direction of operation - these are "Norman's doors". A person opening them for the first time will at least have to think, and most likely also try several incorrect ways of opening them. The inscription "from yourself" on these doors will be the signifier. Flash drives that we always insert the wrong way should probably also be called "Norman's flash drives".

The presence of a signifier, if the object or interface is not visual, reduces the number of errors. In this, Norman's 7 rules intersect with Jakob Nielsen's 10 heuristics. One of them is to prevent user errors with the help of hints and responsiveness of the interface directly at the moment of work with it.

Projections
Projections are, in essence, metaphors of things, their correlation with something in the real world. Metaphors of things differ depending on the cultural context and the language of description. In one country or community they may be completely different from another. Surprisingly, not every culture associates the future with something ahead, and the greater or more positive with something above. Projections are often precisely about spatial connections. The simplest example of Don Norman is switches and lamps. If we see three switches and three lamps, then we mentally automatically cothe main means of transpor