The Principles of Interaction



Don Norman discusses 6 fundamental principles of interaction and how these have a parallel effect on the experience associated with the design. He discusses how each psychological concept relates to the discoverability and total understanding or misunderstanding of the design. Don Norman quotes that “experience is critical, for it determines how fondly people remember their interactions” Norman (2013, p. 10) This experience can be compromised through lack or misuse of the concepts and can cause confusion. ‘Apple Music’ is an App installed on each iPhone display setting and features the abilities to download music and retain your favourite playlists. I am referring to this design model to show examples of each psychological concept.

“Affordance refers to the relationship between a physical object and a person. It is a relationship between the properties of an object and the capabilities of the agent that determine just how the object could possibly be used.” Norman (2013 p. 11) Affordances are how an agent can relate to the design, these affordances can adjust through each individual’s abilities; an object can have an affordance to lift but this depends on the agent’s strength and ability otherwise the affordance is lost. The Apple Music app affords the notions of Downloading, Listening, Playing, Pausing, Skipping, Browsing, Scrolling, Creating. Each of these affordance properties are possible for many.

Signifiers work hand in hand with affordances, they communicate where the affordance action should take place. “The term signifier refers to any mark or sound, any perceivable indicator that communicates appropriate behaviour to a person.” Norman (2013 p. 14) It reveals to the user where and what the affordances are. In this case through Icons, Symbols and Definitions (Instructions). These highlight where affordances can be occupied i.e. An Icon explaining ‘Browse’ navigates the user to the correct area to succeed the browsing affordance; The Display of the universal Play, Pause, Skip symbols let the user understand whether they are playing the chosen song and can navigate through selection.

“Mapping is an important concept in the design and layout of controls and displays” Norman (2013 p. 21) Mapping is the position and placement of signifiers; these highlight the areas that actions can be taken place. The Apple signifier icons are logically mapped to take you straight to the correct area instead of diverting onto an incorrect page. The icons are also logically positioned at the base of the app making their positioning key to the usability. “When the mapping uses spatial correspondence between the layout of the controls and the devices being controlled, it is easy to determine how to use them” Norman (2013 p. 21)

Feedback is “Communicating the results of an action” Norman (2013 p. 23) Initiating a response to the action of the design is important to stop confusion or frustration amongst users. Feedback needs to be an immediate response and of the right level, you don’t want to overwhelm the user with too much information and you also want the feedback to be recognised. Apple Music use symbols to acknowledge that music is being downloaded, this tells the user to wait. It is then visibly displayed in the apps music library letting the user know the download is complete. An audible form of feedback is when the music is playing, the headphones also give feedback when interacting with the volume control button there is an audible and physical response indicating the user has adjusted the volume.

Constraints come in a combination of Physical, Semantic, Cultural and Logical theories. Physical constraints create a semantic barrier, meaning an activity cannot be carried out. “Semantic constraints are those that rely upon the meaning of the situation to control the set of possible actions” Norman (2013 p. 129) An action should be done if it makes sense to do so. Cultural constraints mean we subconsciously abide by the suitable behavioural ways in social situations. Logical is a more technical constraint idea, if you are left with only one piece out of a puzzle but a suitable gap for this piece, logically that left over piece is constrained to fit.  Constraints are most commonly a physical matte. Referring to Apple music; you are constrained to the devices memory capacity, the devices Wi-Fi connection has to be compatible in order to download music and the album needs to be readily available on Apple music in order to be downloaded in the first place.

Conceptual Models “is an explanation, usually highly simplified, of how something works.” Norman (2013 p. 25) Instead of the complicated written manuals conceptual models are evident in the minds of the user, they indicate a simpler version of the system so that the user can have a more general understanding. I.e. when using your computer, you will place documents into a folder, this is a conceptual idea to help you understand and navigate the display however, there is no physical filing system behind the computer. Apple music use a similar idea of folders to organise the music into playlists and categories. When Browsing the music, you associate it with being on your device however it is in fact in the ‘Cloud’. Problems with conceptual models can occur when systems fail. The music on your device can be visually present on the device but may have not been downloaded, this then causes confusion as songs are then un-able to be played.


Norman,D. (2013) The Design of Everyday Things. New York: Basic Books