Situational differences between speech and writing

Biber explains the situational differences between typical speech and typical writing. The notion of typical speech and typical writing is useful because there is no linguistic characterization of speech and writing that is true of all spoken and written genres: in fact, public speeches and written exposition are similar, although they rely on different channels (instead a conversation and a public speech rely on the same channel but they have different features). Biber refers to FACE-TO-FACE conversation as TYPICAL SPEECH and to expository PROSE as TYPICAL WRITING.
There are six components if the situational context which need to be taken into account when distinguishing between speech and writing:

1. Physical Channel
2. Cultural Use
3. Relation of communicative participants to each other
4. Relation of the communicative participants to the external context
5. Relation of the communicative participants to the text
6. Purpose

1. Physical Channel
This refers to the choice of the primary channel and to the availability of prosodic and paralinguistic subchannels.
Speaking uses the auditory channel, while writing uses the visual channel. Writing can be produced to be spoken (a speech, a play) and speech may be meant to be written (dictating a letter).
Writing is restricted to syntactic/lexical channel, whereas prosodic and paralinguistic channels are available when speaking.

2. Cultural use
This refers to the attitudes towards speech and writing and it can be split into three categories:
a) Acquisition versus learning: In Western societies speech is normally acquired at home, while writing is learned at school.
b) Social evaluation: writing is commonly considered as more valuable than speech, so people pay more attention to writing compared to speech.
c) Maintenance of social status: in formal situations, writers and speakers tend to resist features perceived as typical of speech in order to maintain social distance from other classes.

3. Relation of communicative participants to each other
In typical speech the addressee is an active, individual listener, while in writing the addressee is a passive group of reader.
This component can be split into five categories:

a) Extent of interaction: while readers can provide any feedback, in speaking situations listeners may respond directly, providing informations and opinions, asking for clarification and showing understanding and interest. Listeners are under pressure to understand quickly and to respond adequately, in fact a delay on response or an appropriate reply can have significant interpersonal results.

b) Extent of shared knowledge: shared knowledge is variable in speech and writing. In speech however when speakers have an intimate knowledge of the addressee's knowledge, beliefs and interests, they are likely to reduce the amount of informations provided. It can be hard for the outsider to get to the point and it is a problem which can be seen in non-native speakers, because they don't know enough vocabulary or they don't understand fast speaking, but it is a problem also for some people which are not in the know (it is a problem for people that don't share the same knowledge).

c) Negotiability of communicative goal and topic: Such negotiation, which are typical of speech, is impossible in writing, because the interaction between the reader and the text can not change the text itself.

d) Effort required to maintain the relationship: in speech, unlike in writing, a social relationship between the participants must be established at the start of the encounter and maintained through continuous monitoring. In writing, the relationship is established at the beginning and the reader decide if accept or reject the text.

e) Extent of shared cultural knowledge: Speakers are familiar to some extent with the cultural background of the people they interact with. Writers may address readers with a variety of cultural backgrounds.

4. Relation of the communicative participants to the external context
There are two aspects of this component:
Extend of shared space --> speakers and listeners share a physical context, whereas writers and readers do not.
Extend of shared time --> speakers and listeners share a temporal context, while writers and readers do not.

5. Relation of communicative participants to the text
This may be divided into:
a) degree of performance: written texts can be planned and revised and can be read again and again.
Speech has a temporary nature: writing shares many characteristics with a mountain (permanent and ready for inspection) and speech is like the ocean: mutable and difficult to capture and define.
b) speed of production and comprehension: it is much faster ti produce speech than writing, while listeners have to comprehend an oral text as it is produced, readers are free to dedicate the amount of time they wish to understanding a written text.

6.Purpose
Writing is typically associated to ideational purposes while speaking is often meant to achieve interpersonal purposes.