The purpose of this study is to clarify how Japanese adults search for books. In a preliminary survey, university students (n=209) were asked to answer the open-ended questions about how they choose books, and 24 information and items measuring book-search orientation were identified. In Study 1, a survey of university students and adults (n=346) was conducted to develop a book-search orientation scale consisting of two factors: “review-reference orientation” which value external measure such as rankings in book searching, and “serendipity orientation” which value one 's intuition and fortuitousness. In Study 2, 750 adults were recruited with the aim of clarifying (1) the information referencing in book searching and (2) the tendency of book-search orientation by contrasting readers and non-readers. The analysis revealed that the information about the contents of books and a chance encounter were both important in choosing books. It was also shown that serendipity orientation, which value a fortuitousness in book search, may increase the probability of reading. These results suggest that working on its serendipity in book search may be important in promoting reading in adults.

  The present study investigated how Japanese language learners identify the speaker of conversation appearing in the first lines of Japanese literary fiction. The participants in our experiments were intermediate and advanced learners whose native language is Chinese. The procedure was (1) translating the lines into Chinese and (2) multifaceted questions on the content of the story. The results showed that the speaker is identified by the following factors: (1) the sentence-ending particles and conjunctive expressions in the quoted clauses, (2) the conjunctive expressions, the directives, and clause-final modality forms in the narrative parts, and (3)the speaker of other conversations. In addition, factors causing misreading included lack of knowledge of cultural convention and the genre, misuse of vocabulary/grammar knowledge, and another misunderstanding of the content of the narrative. Moreover, in some cases, misreading was avoided by noticing a problem with textual coherence and attempting to reconstruct the context.

  Sakuma (1989) has attracted attention as a theory for grasping the main points of explanatory texts. According to Sakuma (1989), it is possible to determine the degree of importance as topic sentence based on the concept of “Tokatsu(Unifying)”. However, its concept remains unclear, and there are cases in which it is not possible to appropriately measure the importance of topic sentences.

  In this paper, I focused on the contextual effect (i.e. improvement of cognitive environment) in relevance theory as the factor that determines the degree of importance of topic sentences. Relevance theory is a framework for understanding the interpretation of utterances/sentences. It was first proposed by Dan Sperber and Deirdre Wilson, and is used within cognitive linguistics and pragmatics. The cognitive effect normally discussed in relevance theory has three types: to support and strengthen an existing assumption, to contradict and rule out an existing assumption, to interact inferentially with existing assumptions to produce a new conclusion.

  By reading explanatory texts, readers can learn something new, become more persuasive, or correct incorrect knowledge (that is, contextual effects can be generated and then the cognitive environment can be improved). Based on this idea, I put forward a theory the degree of importance of sentences as key points in an explanatory text is determined by the degree of improvement in the reader’s cognitive environment. The reason why the reading comprehension method focusing on problem presentation/answer,summary, abstract/concrete, and adversative is effective is that these are related to contextual effect.

 The distinction between “data” and “warrant,” frequently mentioned in logic education in Japan, remains unclear in many cases, such as the explanations in Japanese language textbooks in elementary and junior high schools and the classifications in the Japanese government's curriculum guidelines (Courses of Study). In fact, across the history of practice and research, scholars have rarely explained the distinction between the two concepts in a clear and understandable manner, leaving them ambiguous at present. In light of this scenario, the primary objective of this paper is to examine the warrants for the difficulty in understanding and firmly establishing the concepts of data and warrant through a description of the Courses of Study and a content review of elementary and junior high school Japanese language textbooks. The second objective is to examine the meaning of the three elements of the Toulmin Model that are not frequently addressed in Japan, and to review the validity of their adoption on the basis of their differences from the canonical Toulmin Model, which is typically used as a basis for considering the two concepts, data and warrant.

 A review of the Courses of Study reveals that while “warrant” is the concept addressed in elementary schools, only “data” is discussed in junior high schools; yet the relationship between the two concepts is left unexplained. Moreover, it is unclear how the two concepts can be differentiated to explain their properties without confusion. However, an examination of Japanese elementary and junior high school language textbooks reveals that “data,” a concept that does not appear in elementary schools, is used in junior high schools with only a vague explanation as to what differentiates it from “facts,” and a logical inconsistency regarding why subjective personal ideas would be considered “data.” After pointing out these issues, this study discusses the differences with the Toulmin Model, which is often used as a basis for logic education in Japan and presents the following conclusions:

  1. In Japan, only the three-point set of data, warrant, and claim is used, which may be partially due to the ambiguity emerging from the lack of distinction between the concepts of “argument/claim” and the act of “explanation.” Accordingly, the importance of the three elements intentionally included by Toulmin, “backing,” “qualifier,” and “rebuttal,” is no longer taken into account in Japan.

  2. When considering the essence of the act of “argument/claim,” in light of the meaning of why such an act is necessary, one recognizes that an underlying sense of uncertainty and ambiguity is required: a claim is over something that has not been previously determined. By contrast, a series of propositions that are certain and well-known to everyone should be categorized as an act of “explanation.”

  3. Therefore, Japanese logic education must reexamine the essential difference between the acts of “argument/claim” and “explanation,” and use the results of this inquiry to redefine the concepts of “data” and “warrant.” At the same time, how to address ambiguities in the process of making an “argument/claim” should be fundamentally reconsidered.