Question Understanding from the Perspective of Context Theory

This paper uses context theory to study the question in natural language. In syntax, questions can be classified into polar questions, alternative questions, concealed questions, and inquisitive questions. In semantics, it can be divided into polar questions and inquisitive questions. Only inquisitive questions with characteristics of inquisitiveness, informativeness, compliance, and transparency need to be studied by context theory. There are three levels for question context: question-answer facts, background knowledge, and question presupposition. The question context composes the possible world where the question is. Question understanding is a function of the mapping of the question through the possible worlds, and the set of propositions consisting of different possible worlds of the question context and the set of propositions consisting of different possible answers to the question are mapped to each other, resulting in different answers in different possible worlds of the same question.

answers: p, q. This is an alternative combination of possible answers to the polar question ?p and the polar question ?q. For example, the possible answers to the alternative question "Is light a particle or a wave?" --"Light is a particle" or "Light is a wave" --are the semantic combination of possible answers for the polar question "Is light a particle?" and the polar question "Is light a wave?". Through the semantic analysis of the answer to the alternative question, it is concluded that the final set is the combination of the answer set of the polar questions. From a pragmatic point of view, the answers to alternative questions are limited by the question index. Therefore, alternative questions can also be seen as polar questions.

Concealed Questions
Concealed questions are phrases that can be interpreted as embedded questions, including definite determiner phrases, indefinite determiner phrases, quantified determiner phrases (Floris Roelofsen & Maria Aloni, 2008).

E.g.:
I know that light goes in a straight line. ≈ I know "Does light go in a straight line?".
I know the form of light transmission. ≈ I know "What is the form of light transmission?".
I know every paper provided by this scientific conference. ≈ I know "How many English papers and Chinese papers are provided at this scientific conference?" Through the above example, it can be seen: The proposition "I know that light goes in a straight line" contains the definite determiner phrase "light goes in a straight line", which means that I know the answer to the polar question "Does light go in a straight line?"; The proposition "I know the form of light transmission." contains the indefinite determiner phrases "the form of light transmission", which means that I know the answer of the inquisitive question "what is the form of light transmission?"; the proposition "I know every paper provided by this scientific conference" contains the quantified determiner phrases "every paper provided by this scientific conference" means that I know the answer to the quantified question "How many English papers and Chinese papers are provided at this scientific conference?". The concealed question is only morphologically embedded in a declarative sentence, but the concealed question can be analyzed separately in terms of semantics and pragmatics. Therefore, we 30 www.scholink.org/ojs/index.php/jrph Journal of Research in Philosophy and History Vol. 4, No. 2, 2021 can ignore the syntax particularity of the concealed question, and divide it into a polar question or an inquisitive question from the perspective of pragmatics.

Inquisitive Question
Inquisitive questions take the form of special interrogative sentences. Because special interrogative sentences begin with interrogative noun phrases or adverbs, such as which, where, when, who, why, how, etc., most of them start with the letter wh, so they can also be called wh-questions. Hintikka first noticed the huge ambiguity between the detailed explanation and the existing interpretation of the wh-questions (Jonathan Ginzburg, 1995). Later linguistic philosophers gradually discovered in their research on the inquisitive questions that the inquisitive questions have multiple unique characteristics such as inquisitiveness and informativeness, and it cannot solve the problem of understanding the inquisitive questions from the perspective of syntax and semantics. Therefore, it is a promising path to study inquisitive questions from the perspective of pragmatics. This article will analyze the peculiar attributes of the inquisitive questions in detail in the next section.
In terms of question syntax, interrogative sentences have many forms. However, from the above analysis, we can see that from the perspective of semantics and pragmatics, there are mainly two types of questions, namely, inquisitive questions and polar questions. The most fundamental difference between these two questions lies in the possibility of answering them. The possibility of answering the polar question is fixed, and it is easy to form a knowledge closure. In contrast, the answer to the inquisitive question is open and inquisitive, and there are many possibilities.
Therefore, how to answer inquisitive questions needs to be considered by the respondent according to different contexts or other constraints. This requires the analysis of inquisitive questions from the perspective of context theory. For example, in the question of the form of light propagation, from a semantic level, one can only choose whether the light travels in a straight line, whether it is in the form of light waves or an electromagnetic process. However, light may be not only light waves or electromagnetic waves, but also light particles, wave-particle duality, etc. These options are not available in the polar question, and the answerer cannot give it. Because classical semantics requires strict compliance with logic, and from a logical point of view, no other assignments are given in the question, and new assignments cannot be added to the answer. This shows the limitations of the polar problem. Polar questions are prone to unsatisfactory answers, and answers that are not close enough to the facts. Therefore, combining context and other factors, thinking and answering questions from a pragmatic perspective can be more consistent with the facts, and more satisfactory and more appropriate answers can be obtained.

Inquisitive Question and its Characteristics
Hintikka once said: "The logical form of a wh-question (which, who, where, etc.) consists of an imperative operator plus a description of the cognitive situation the questioner wants to be brought about (the latter is the desideratum of the question) (Jaakko Hintikka, 1979 Vol. 4, No. 2, 2021 Inquisitive questions can be called wh-questions in terms of syntax; in terms of semantic, they can be called search questions (Lauri Karttunen, 1977). Because it is not enough to answer this kind of question, just from the semantic assignment provided by the question itself. It is unlike the polar questions, which only have two assignments, positive and negative. It is also unlike the alternative question, which have several options. If you want to answer an inquisitive question, the cognitive agent needs to give play to its rational subjective initiative and actively think about it. Thinking needs to combine the context of the question and use the cognitive method of pragmatics to conduct specific contextual exploration. Therefore, from the perspective of pragmatics understanding, such questions can be called inquisitive questions.
Inquisitive questions have many characteristics, such as inquisitiveness, informativeness, compliance, and transparency.

Inquisitiveness
The concept of inquisitiveness comes from inquisitive semantics. Its basic concept is "The basic idea of INQ can be briefly expressed as follows: the meaning of a sentence comprises two components, informative content, and inquisitive content. The former is the information provided by a sentence, and the latter is the issue raised by the sentence. By and large, if the information provided is sufficient to settle the issue that is raised, the sentence is an assertion. If, however, the information provided is insufficient to settle the raised issue, the sentence is inquisitive." (Shalom Lappin & Chris Fox, 2015).
If there are multiple possibilities for a question and the answer needs to be determined based on the context, the question is inquisitiveness.
Inquisitiveness Definition: Q is inquisitiveness, if and only if [Q] contains at least two possible answers (Jeroen Groenendijk & Floris Roelofsen, 2009). According to this definition, contradiction and tautology are not inquisitiveness.

Informativeness
Only questions with informativeness are worthy of interpretation in the context. Informativeness refers to questions with information content. That is, question Q is informativeness in world w if and only if question Q remains a possibility in world w, and question Q excludes a possibility at least in world w.

The informativeness of questions requires that Questions cannot be eliminated in the information state
of question-answer participants, and their existence is necessary for the sense of information.
Furthermore, informativeness requires that the question be able to affirm certain information and at the same time negate the contradictory information. According to this definition, contradictions and tautologies are not informative. The presupposition of the question is also the embodiment of the informativeness of the question, and the preconditions for providing information cannot be separated from the question itself.

Compliance
Compliance can determine the relevance between utterances, but it is more stringent than relevance.
Compliance stipulates the consistency of information exchange, judging whether a certain questioning behavior is related to a certain context. Therefore, compliance is essentially contextual information compliance.
Question compliance refers to the verbal questioning behavior that is relevant to the above context. In a sense, compliance is a restriction on informativeness, limiting the information's requirement of the question to be relevant to the context. At the same time, the concept of compliance only makes sense when the agent's intent to know and the question are inquisitiveness. Therefore, compliance is further regulation of the inquisitiveness and informativeness of the question.
When cognitive participants intend to know, they may propose several different possible question expressions, and the last question asked is the best compliant, that is, the most compliant with the previous context. And this last question is one of the different possible forms of question expression.

Transparency
The interactivity of the question-answer requires that the question must be transparent, or at least transparent among all question-answer participants. The meaning of the question should be public and can be circulated. "The transparency of understanding is the conscious experience that accompanies understanding, which the knower can introspect, thereby learning that they now understand something new." (Andrei Mărăşoiu, 2019) Transparency is a necessary requirement for language communication. All participants should maintain the common ground and the information state of each individual appropriately, and respond to the words given. In particular, unacceptable opinions should be publicly announced, and words that no one opposes should be incorporated into the common ground and the information state of each participant.
This requirement is called transparency. Questions and answers are open and transparent to all participants so that they can be supported, questioned, or denied by everyone.
It is clear from this subsection that among the various natural language questions, only the answers to inquisitive questions are non-closure, and not limited by the assignment of the question itself.
Therefore, the answer to an inquisitive question should not be limited to the syntax and semantics of the question itself but should be understood based on the characteristics of the question. The most important characteristic of inquisitive questions is that the answers to the questions need to be explored in the question context. The question context needs to be analyzed to understand and answer the question.

Level of Question Context
Since Frege put forward the "context principle", the context principle has received more and more attention, and context analysis has gradually become an important research method in analytical philosophy. The question is a kind of language behavior. To understand the question, we need to understand the context of the question language and the context which question effecting, because the question lies in the context. Questioning is a kind of verbal behavior.
To understand and answer questions, we must start from the syntax and semantics of the question, pay attention to the facts of the questioning behavior itself, and place the question in the context it is trying to influence. Context is the source of the meaning of the question and the object of the question's effect, where the question has been arisen, understood, and answered. The author believes that the question context can be divided into question-answer facts, background knowledge, and question presupposition.

Question-answer Facts
The question-answer facts are explicit and the most directly knowable. It includes the context, time, places, question-answer participants, and their reflexive self-awareness, which is the question-answer participants know that they are in the question-answer dialogue.

Background Knowledge
Background knowledge refers to the background knowledge base of both sides of the question-answer.
The essence of question-answer behavior is information exchange. At the beginning of the question-answer, both question-answer participants have some common information of factual meaning or expected meaning. This information constitutes the initial context of the question-answer and is also the part that the question-answer behavior is trying to influence. Of course, in the expectations of the question-answer participants, some information seems to be the information they agree with, but it is not. Question-answer participants may misjudge the other participants' presupposition. However, in actual communication, the consistency of information must be maintained to the greatest extent to ensure the consistency of background knowledge. Usually, this information content is composed of assertions. If the assertion is successful, that is, it is approved by both participants to the question-answer. The assertion will become part of the initial context and affect the subsequent question-answer dialogue (Robert Stalnaker, 1998). Context-dependent means that the question-answer is based on facts available in a certain sense or expected sense. Therefore, the context of the question-answer contains the information shared by the question-answer participants.

Question Presupposition
Question presupposition is the cognitive agent's expectations of the question. Compared with background knowledge, the presupposition is more personal and fallible. "Roughly speaking, the presuppositions of a speaker are the propositions whose truth he takes for granted as part of the background of the conversation..... Presuppositions are what is taken by the speaker to be the common ground of the participants in the conversation, which is treated as their common knowledge or mutual 34 knowledge. " (Herbert H. Clark, 1992). Due to the personal feature of the presupposition, there may be differences between the actual presupposition of the questioner and the actual presupposition of the answerer. But the questioner or answerer may not be aware of the question, that is, the question presupposition lacks reflexivity. Among the presuppositions of the questioner or answerer, the presuppositions of the question-answer participants are the same, that is, their presuppositions are also the presuppositions of other participants. Question-answer participants will assume that their presupposition is the common basis for all question-answer participants, but this is not necessarily the case. What the questioner or answerer presupposes is not necessarily a common basis. As the question-answer dialogue progresses, everyone's presupposition will gradually be adjusted, and finally, they will be in a relatively coordinated state of equilibrium which acceptable to all communities.
The presupposition of the question is the unified conceptualization of its answer and the embodiment of the question's information. Question presupposition is a question element in the form of a proposition, that is, the presupposition is the propositional component of the question, which will affect the understanding and answer of the question. Early philosophers who studied questions such as Bernap and Steele define a question as presupposing a statement if and only if the truth of the statement is a logically necessary condition for there being a true (i.e., correct) answer to the question (Nuel D. Belnap & Thomas B. Steel, 1976). The presupposition of the statement in the question is true so that the question has a true answer. The converse is the same. For a question to have a true answer, the question must contain a true statement presupposition. The question itself contains the relationship between the presupposition and the answer. A true question must presuppose a true statement so that the question has a true answer. A question has one or more presuppositions, and answering the question positively is actually acknowledging the presupposition positively. The presupposition of the question must be true to answer the question positively. In terms of the true answer to the question, the logic of presupposition must be true. The presupposition of a question is the logical condition necessary for its true answer. A presupposition is a necessary condition for answering. True questions need to presuppose a true statement to have a true answer. Only when the presupposition is true, can the question be answered positively. For the answer to the question, the question must be logically true.

Possible World of Questions
The possible world is proposed by Leibniz in "Discourse On Metaphysics", Leibniz believes that our world is the best of all possible worlds. In 1968, Richard Montague used Pragmatics (Richard Montague, 1968). In 1969, the represent of David Lewis made the world a widely known philosophical possible creed (David Lewis, 1969). Lewis believes that there are other possible worlds besides the real world. There may be countless other ways of being, which is a quantification of being. (Jaakko Hintikka, 1983) An object should exhibit differences or display its unanticipated properties in different conditions or different contexts. All empirical knowledge is relative to various objects, conditions, historical or cultural contexts, and changes with context. We cannot and need not resort to artificial language to disambiguate words; the richness of context itself already sets up a flexible, vivid, and transformable possible world for words. Therefore, its effective meaning can only be obtained in specific contexts.

Proposition-Set Theory
In general, the context in which a speech act occurs can be represented by

. Question Understanding and Answers Mapping
The following is illustrated by case studies: Example: Who is the chairman of this scientific congress?
Background: The International Solvay Institute is holding the fifth Solvay Conference on Physics, and Hendrik Lorentz is the chairman of this conference.
Scene 1: A newspaper journalist A is preparing promotional materials for this conference, and the editor of the newspaper asks journalist A: "Who is the chairman of this scientific congress?" Question understanding 1: What is the name of the chairman of this scientific congress?
Answer 1: The appropriate answer to this question at this point would be "Hendrik Lorentz".
Scene 2: During a break in the meeting, a young scholar wants to talk to the chairman of the meeting and asks journalist A: "Who is the chairman of the scientific congress?" Answer 2: The appropriate answer to this question at this point would be "That person (pointing to Hendrik Lorentz)." Analysis: In Scene 1, name identification is an effective method of question understanding. In this context, knowing the name of the person is proof of knowing who the chairman of the scientific conference is, without the need to identify him. In Scene 2, appearance identification is a valid method of question understanding, in which the identification is sufficient to know who the chairman of the congress is, without the need to know the name. If someone knows that Hendrik Lorentz is the chairman of the fifth Solvay Conference on Physics, but does not recognize the conference chairman.
As can be seen, the answers to the same question, with the same information available to the respondent, vary according to the scene, with no change in background. In the above case, journalist A can identify both the name and the appearance of the chairman. But in the possible worlds composed of different scenes, the respondent gives different answers to the same question. It can be seen that the answers change with the possible worlds.

Conclusion
In this paper, we have put forward a promising approach that context theory can be used to address the problem of question comprehension in natural language. In natural language, analyzing the context of the question allows for understanding and answering the question itself. The paper thus advances the current research into Linguistic question pragmatics.
This study has shown that questions can be divided into polar questions, alternative questions, concealed questions, and inquisitive questions in syntax, and be divided into polar and inquisitive questions which have several characteristics such as inquisitiveness, informativeness, compliance, and transparency in pragmatics. The study has also shown that the question context consists of question-answer facts, background knowledge, and question presuppositions. The paper concludes with proposition set theory to provide a framework of possibilities for the understanding of the question.
This paper has provided a deeper insight into characteristics of wh-questions which are informative and inquisitive in unity, and shed new light on the question context which is composed of question-answer facts, background knowledge, and question presupposition.
Several issues are not addressed in this study. How to classify different contexts according to the change of the question context level? Should there be different question contexts for different agents?
Does the division of the question context need to be unified? If so, how to unify it? I suggest that the study of changes in the question context level involves the cognitive state of subjects and requires cooperation with the brain neuroscience, the computer science, and other disciplines. It is a feasible path to conceptualize the cognitive subject's perception of question context change through computational modeling and logical analysis.