language in advertising. It seems they all agree deviation is an impactful tool in obtaining public attention, but the reason why deviation gains so much popularity is not fully investigated. In those a few papers which do deal with the above-mentioned issue, some try to approach the interpretation of deviation through Cooperative Principle and some try Relevance theory, which is the same theory this thesis relies on. Deviation in English Advertising and Its Interpretations by Wang Wei is a typical dissertation in this regard. The difference between her dissertation and this thesis is the former interprets deviation from four aspects(linguistic account, pragmatic account, psychological account and aesthetic account ) so that the interpretation of deviation from the perspective of Relevance Theory is not detailed. This thesis endeavors to make a deeper analysis in this rarely touched field.
2.Relevance Theory
Sperber and Wilson put forward Relevance Theory in the book \Communication and Cognition\mode of communication, namely the encoding and decoding mode proposed by Shannon and Weaver in 1949, is deficient. On the other hand, they reduce Grice’s Cooperative Principle to a simple theory of relevance, which makes a milestone in the history of pragmatic study.
Sperber and Wilson claim that to communicate is to claim someone's attention; hence to communicate is to imply that the information communicated is relevant, which is called in the book the principle of relevance (2003, 487). Now every utterance starts out as a request for the hearer's attention. As a result, it creates an expectation of relevance. It is around this expectation of relevance that the criterion for evaluating possible interpretations of an utterance is built (Wilson 447) In other words, communication of human is a process of searching for relevance.
2.1 Definitions 2.1.1 Relevance
According to Hu (2001), there are three definitions of relevance.
The first one is defined by Sperber and Wilson in relation to contextual effects : An assumption is relevant in a context if and only if it has some contextual effect
in that context.(122) In other words, having contextual effect is the premise of relevance of an assumption.
Afterwards, Sperber and Wilson future take into consideration the processing effort(See 2.1.2 Cognitive effect and processing effort), which therefore generates an extent-condition format as follows:
Extent condition l: an assumption is relevant in a context to the extent that its contextual effects in this context are large.
Extent condition 2: an assumption is relevant in a context to the extent that the effort required to process it in this context is small (125)
It is worth mentioning that Relevance Theory is different from Grice’s theory, where assumption and context is given. (Xiong，101) In Relevance theory, the size of context is determined by the assumption to process. It is not given, but chosen. It is not that there is a context, on which the relevance of an assumption depends. What is given is relevance. People generally assume that the assumption they are processing is relevant, then try to find a context in which its relevance will be maximized.(Hu，88) That is to say, the assumption and relevance are given, but the context is a variable.
The second definition of relevance relates it to an individual. (Hu，2001):An assumption is relevant to an individual at a given time if and only if it is relevant in one or more of the contests available to that individual at that time. (144)
The third definition involves the characterization of relevance “not just as a property of assumptions in the mind, but also as a property of phenomena(stimuli, e.g. utterances)
in
the
environment
which
lead
to
the
construction
of
assumptions”(155-151)
Therefore, the definition of relevance becomes: A phenomenon is relevant to an individual if and only if one or more of the assumptions it makes manifest is relevant to him(152) This means, relevance is established when the communicator makes known its intention through “stimuli”.
To understand this definition better, please see the definition of manifestness in 2.1.3 “ Mutual manifestness and mutual cognitive environment” and the definition of stimuli in 2.2 “Ostensive-inferential communication”. It will be further discussed in
2.3 “Optimal relevance and principle of relevance.”
2.1.2 Cognitive effect and processing effort
The degree of relevance is defined in terms cognitive effects and processing effort.（Wang W,2005） Cognitive effects are achieved when newly-presented information interacts with a context of existing assumptions by strengthening an existing assumption, by contradicting and eliminating an existing assumption, or by combining with an existing assumption to yield a contextual implication. The greater the cognitive effects, the greater the relevance will be. (Sperber and Wilson 1997, 8)
On the other hand, Wilson (449) holds that the processing effort required to understand an utterance should also be considered. The processing effort depends on two main factors: First, the effort of memory and imagination needed to construct a suitable context; second, the psychological complexity of the utterance itself. Therefore, processing effort is a negative factor. Other things being equal, the lower the processing effort, the greater the relevance will be. （Wang W,2005）
2.1.3 Mutual manifestness and mutual cognitive environment
In the part of 2.1.1.Relevance, we have learnt that a phenomenon is relevant to an individual if and only if one or more of the assumptions it makes manifest is relevant to him. Then what is “manifest”? Sperber and Wilson (2001，39) hold that to be manifest is to be perceptible or inferable. Manifestness exist in two forms: first, they extend it from facts to all assumptions; second, they distinguish degrees of manifestness. Manifestness is a property not only of acts but more generally, of true or false assumptions. It is a relative property. acts and assumptions can be more or less strongly manifest. Manifest is weaker than known or assumed. A fact can be manifest without being known or being assumed. （Peng,2008）For instance, one happens to see a musician playing on the television. The viewer has no knowledge or assumption about this musician, but the fact that the musician is playing this song is manifest to the viewer.
A cognitive environment of an individual is a set of facts that are manifest to him, that is, facts he can perceive or infer, or in other words, a function of his physical environment and his cognitive abilities. (Sperber and Wilson 2001，39) \
cognitive environment in which it is manifest which people share it is what we will call a mutual cognitive environment\people who attended the same lecture share a mutual cognitive environment, which means they have access to the same information presented in the lecture.
In terms of mutual manifestness, Sperber and Wilson's believes(2001，41), the same facts and assumptions may be manifest in the cognitive environment of two different people. In that case, these cognitive environments intersect, and their intersection is a cognitive environment that these people share. One thing that can be manifest in a shared cognitive environment is a characterization of those who have access to it. (Peng,2008) One clarification needs to be made is that when a piece of information is mutually manifested to two people, it doesn’t guarantee they perceive the information in the same way. Back to the example of listening to a lecture, we can safely arrive at the conclusion that the two people do not necessarily have identical understanding of the content of lecture.
2.1.4 Informative intention and communicative intentions
Informative intention is to make manifest or more manifest to the audience a set of assumptions (Sperber and Wilson 2001，58)
Communicative intention is to make it mutually manifest to audience and communicator that the communicator has this informative intention. (Sperber and Wilson 2001，61)
The relation between informative intention and the communicative intention is the latter makes manifest of the former.
2.2Ostensive-inferential communication
Ostensive-inferential communication can be defined as communication in which the communicator produces a stimulus which makes it mutually manifest to communicator and audience that the communicator intends, by means of this stimulus, to make manifest or more manifest to the audience a set of assumptions I. (Sperber and Wilson 2001，63)
A stimulus is a phenomenon designed to achieve cognitive effects. (Peng,2008) That is to say a stimulus is made intentionally. It is hoped to alter a cognitive
environment and create certain cognitive effects through the presentation of a stimulus.
Ostensive stimulus makes an informative intention mutually manifest. In human communication, people will process the stimulus because they have the expectation that the stimulus must be relevant to them. What happens next is the stimulus makes communicator’s informative intention manifest for both the communicator and the receiver. and then the receiver an process communicator’s information. In this way a mutually manifest cognitive environment is shaped by the stimulus.
\Ostension, the first phase, means to make an intention manifest. Showing someone something by pointing at it is a case of ostension and thus it is a kind of human intentional communication (Sperber and Wilson 2001，49). Ostension consists of the revelation of two layers of information. The initial layer is the information which the communicator points out to the audience. The second layer consists of the information that the first layer of information has been intentionally made manifest (Sperber and Wilson 53)
The second phase of ostensive-inferential communication is inference. Inference refers to the process in which the audience makes an interpretation of the communicator's communicative intention from the ostensive act of the communicator under the guidance of deductive rules.（Peng,2008）Simply put, it is the attempt to infer the meaning of communication and understand the speaker's intention.
2.3 Optimal relevance and principle of relevance
Relevance is defined as a phenomenon is relevant to an individual if and only if one or more of the assumptions it makes manifest is relevant to him(152) Then what is an optimal relevance?
According to Sperber and Wilson, optimal relevance is achieved when
(a)The ostensive stimulus is relevant enough for it to be worth the addressee's effort to process it
(b)The ostensive stimulus is the most relevant one compatible with the communicator's abilities and preferences (2001，270)