Week 3: Affordances and Constraints

Text 1: Norman, D 1998, The design of everyday things , Basic Book, New York (Sections: Preface vii-xv; Chapter one pp 1-13; Chapter 4 (constraints) pp 81-87; (computers) pp 177-186).

Text 2: Norman, D 1999, ‘Affordance, conventions and design (Part 2)’, Nielsen Norman Group, viewed 1 April 2012, http://www.jnd.org/dn.mss/affordance_conv.html

“The result is a world filled with frustration, with objects that cannot be understood, with devices that lead to error. This book is an attempt to change things.”

This week we looked at affordances, which I understand best as – the ability of a user to engage with something in ways that are different to what it was actually designed for.

At first I couldn’t quite grasp the concept, but then everything clicked when Norman introduced ‘perceived affordances’, those things that a user perceives an object to do. And that’s when I realised that my grandma is a pioneer on the subject, let me explain. Once my family came back from Europe with a fabric, quilted toast basket, she said she loved it and would use it a lot. The next time we visited my grandma, she had untied that toast basket and used it as a back cushion for her wooden dining chair. Now that’s what i call a perceived affordance. This is what made me agree with and understand the argument that ‘the presence of an affordance is jointly determined by the object and the ability of the person who is interacting with the object’.

This reading provided many terms which need to be defined for me to understand them. They follow;

Natural Signs:

In The Design of Everyday Things (1998) Norman then goes into the ‘psychological principles’ that can be followed to make objects ‘understandable’ (p.3), the central principle being visibility which allows users to understand ‘natural signs’. Natural signs are ones that provide enough obvious direction for a user to engage without being told by signs, images or symbols. The example that Norman uses and which I think is perfect is the metal plate on the side of a door indicating that it is supposed to be pushed.

Affordances and Constraints:

Constraints come hand in hand with affordances. The example provided by Norman(1998) is: the holes in scissors provide an affordance – they are something to put your fingers into. But the size of the holes provide a constraint, because they limit the number of fingers that can be inserted. The mapping between the size of holes and the amount of fingers creates a set of possible operations for the user which are suggested by the affordances and constraints of the holes which now give an indication of how to use the scissors. ‘Affordances suggest the range of possibilities, constraints limit the number of alternatives. The thoughtful use of affordances and constraints together in design lets a user determine the proper course of action.’ (Norman, 1998, p. 82)

Physical Constraints:

Physical limitations constrain the possible ways of operating a device. They are the physical aspects that determine how one part may fit with another. They rely on the properties of the physical world for operation and no training is required.  

Semantic:

These constraints rely on the situation to provide an answer and that is provided by our understanding of the world. The example provided by Norman is a windshield is used to protect a rider so therefore it must be in front of the rider. ‘Semantic constraints rely upon our knowledge of the situation and of the world. Such knowledge can be a powerful and important clue’ (Norman, 1998, p.83)

Cultural:

“Rely upon accepted cultural conventions, even if they do not affect the physical or semantic operations of the device.” (Norman, 1998, p.83)

Logical:

Norman (1998, p.83) argues that ‘there is a logical relationship between the spatial or functional layout of components and the things that they affect.’ His example being that for the Lego motorcycle to be completed all 13 pieces that came with the set should be used, and if they aren’t then the user has made an error.

In the lecture and tutorials we went into more detail about the prompt which made it more clear how the prompt relates back to affordances. The way I understand this is that media publishers need to understand how Instagram can be used to publish digital content and how to produce suitable content for it. One example that came to mind is the introduction of Instagram stories, there is an increasing push for vertical video as apps are designed for vertical viewing, this has been introduced through Instagram Stories and IGTV. This is a physical constraint because Instagram as an app is designed vertically, it is also a cultural constraint as people are more used to vertical video and don’t want to turn their phone, it could also be viewed as a semantic constraint because everyone posts vertical videos on instagram and thus I must post vertical content.

Norman’s article on Affordances, Conventions and Design really helped me make sense of the Design of Everyday Things, I think the concept of ‘perceived affordances’ is more applicable to the designs of devices because there is no way a designer could think of all the affordances that each individual may create. Therefore, perceived affordances make more sense, as they are what the users believe the device could be used for.

All in all this week’s content has taken the most time to wrap my head around, there are lots of definitions but i think that once i start to pick up affordances and different constraints in the world around me I will get a better understanding of what categories are present in everyday objects.