Semantics deal with the study of meaning. There are diverse views concerning this field of study. The logico-philosophical tradition views semantics as the relation between expressions and the what they are about in terms of the world or some other model. Some other views reject the notion of semantics dealing with things external to the language. Several others do not accept the autonomy of semantics from pragmatics (relation between expressions and their use in context).
One of the important issues in the study of semantics concerns with the way people understand the meaning of novel sentences. According to the view of formal semantics, semantics must explain how meanings of smaller parts combine to form the meaning for a larger whole, leaving syntax to describe the part-whole structure. Compositional semantics goes beyond the level of sentences, and deals with the interpretation of discourses.
A second major issue in this area deals with the nature of meanings of the smallest meaningful units (words, morphemes, submorphemes). This area of study is done in the realm of lexical semantics, which is older than compositional semantics.
Some other areas of research focus on the interfaces between syntax and semantics as well as semantics and pragmatics, in addition to acquisition, human semantic processing and computational semantics.
Some of the crucial areas of research focus as well as academic interest in the field include ambiguity (lexical or structural), vagueness (very similar to ambiguity), anomaly (syntactically well formed but semantically anomalous), entailment (natural logic), presupposition (precondition for the truth-valuedness of an expression in a context), context (linguistic context & non-linguistic context), and referential opacity.
There are several issues of semantics that are important to cognitive science. One of the key issue is concerned with the nonpsychological tradition of objective meaning vs the meaning in the head view of psychology. Another issue deals with the distinction between the representational view of semantics as held by psychologists and AI researchers, as compared to the model-theoretic view by others. The role of natural language metaphysics in semantics is yet another major issue. It deals with the impact of human conception regarding the structure of the world on the human language. The question of semantic atomism is another issue , where the main question address the possibility of semantic decomposition and atomic concepts. Finally, the relation between meaning and use forms an important issue, which deals with the distinction between the sentence meaning and the speaker"s meaning.