CMNS2600 Chap.6 Materiality, Affordances and Biometrics
Materiality, Affordances and Biometrics
Materiality brings devices, spaces, bodies and infrastructures into audience analysis. A cinema, newspaper and mobile interface each organise posture, attention, privacy and action differently. Affordances are relational action possibilities: they depend on an artefact, a user and a condition. Software can enable creativity while disciplining it through defaults, templates and ranking.
Biometric instruments add another layer by recording bodily signals, but a signal is not a direct emotion. Valid interpretation requires an explicit chain from stimulus and measurement to inference, validation and limit. This relational approach avoids turning a technical feature into a universal capacity.
A control can be visible but unavailable, usable at home but risky in public, or accessible to one body while excluding another. Defaults also distribute effort by making one path ordinary and alternatives costly. Material analysis follows those practical conditions before drawing conclusions about choice, participation or attention.
What this chapter covers
- 01
Material devices and spaces of audiencing
- 02
Interface design as a condition of action
- 03
Affordances as relational possibilities
- 04
Perceived, available and practical action
- 05
Templates, defaults and programmed creativity
- 06
Recommendation and ranking as distribution
- 07
Biometric signals and psychological inference
- 08
Monitoring, consent, storage and secondary use
Worked example · free
Audit a reaction feature
- +1Name the fast expressive action provided to readers.
- +1Explain how the fixed categories constrain nuance.
- +1Trace reaction data into ranking and visibility.
- +1Conclude with enabled action and programmed consequence.
Key terms
- Materiality
- The physical and technical conditions through which a medium and its audience practices take form.
- Affordance
- An action possibility arising through the relation between a user and an artefact or system.
- Perceived Affordance
- An action a user understands as available through cues in an interface or object.
- Default
- A preselected condition that reduces effort while making one path more likely than another.
- Biometric Signal
- A measured bodily response used as evidence in an inference about attention, cognition or emotion.
- Actuation
- The use of system knowledge to alter conditions and influence a later action.
Materiality, Affordances and Biometrics FAQ
Is an affordance a feature of an app?
Not by itself. An affordance describes a relation among a user, an artefact and a condition. A sharing button may support one person's action but remain inaccessible, invisible or unavailable to another. Name the action and the user instead of treating the feature as universally empowering.
Why do defaults matter for audiences?
Defaults reduce friction and make one route more likely, often without preventing alternatives. They can guide privacy, notification, autoplay or creation choices at scale. Analyse the action encouraged, the effort required to change it and the institutional interest served by the preselected path.
Can biometric data reveal emotion directly?
No. A bodily signal such as arousal or gaze duration can support an inference only with calibration and context. Similar signals can accompany different states. Combine the measure with other evidence, explain the interpretation chain and preserve alternative explanations such as confusion, movement or surprise.
Assessment move
Audit one familiar interface by listing the device, coded options, default path, possible user actions and returned data. Rewrite each broad affordance claim so that it names a user and condition. For biometric examples, draw the chain from stimulus to instrument, signal, proposed psychological state and validating evidence. Mark every inferential jump.
Practise distinguishing attention from agreement and arousal from a named emotion. End each analysis with both sides of the relation: what the system enables and how it shapes or monitors the same action. Run a comparative material walkthrough using the same content on two devices or in two settings. Record screen size, posture, sound, privacy, connection, interruption and the gestures required to proceed.
Do not assume that the smaller device simply offers less; it may enable mobility or private listening while constraining shared attention. Turn every observation into a relational sentence that names the user and condition. Audit defaults by timing the standard route and the route needed to refuse, undo or customise it. Note whether alternatives are visible, reversible and equally functional.
This provides concrete evidence for claims about friction without treating users as mechanically controlled. For biometric revision, colour-code observation and inference. A gaze location, pulse change or skin-conductance measure belongs in the observation colour; attention, excitement or fear belongs in the inference colour. Between them, write the calibration, context and corroborating evidence.
If several emotions could fit, keep the conclusion at arousal or attention rather than choosing the most dramatic label. Finish with an ethics pass that asks whether the bodily signal was necessary, how long it remains useful, who could reuse it and what the participant can withdraw. Accuracy does not settle whether intimate measurement is proportionate.
