The construction of coherence in multimodal discourses is the central issue in this book.A theoretical and analytical framework of analyzing coherence has been put forward for this purpose.Structured around this framework，semiotic analysis and empirical studies are conducted on the basis of English learning advertisements as a specific genre of multimodal discourses.In each of these research phases，there are inevitably limitations that need to be noted.

First of all，this book emphasizes on the semiotic configurations of the English learning advertisements as a type of multimodal discourses rather than their sociolinguistic significance.Therefore it does not consider much the socio-cultural context in which the English learning advertisements have been produced and the underlying social meanings they convey.That is，the socio-cultural meanings of these English learning advertisements are beyond the scope of this book.However，they are very important and deserve the attention of future research.

Secondly，the three-level analytical framework might not cover all the possible factors that contribute somewhat to the connectivity of the multimodal discourses.For example，the relevance of the discourse units with the social context，the reader's interest and involvement in the task have been reported by many researchers to have influence on the establishment of a coherent comprehension of discourses.However，with a reader-oriented approach to discourse coherence，we aim to study how the reader，as a mental being instead of a social being，makes efforts to establish a coherent and organized mental representation of the discourse through interacting with the textual cues.Therefore，we have to keep aside the social context factors，the individual differences among readers，and possibly many other factors.The treatment of discourse coherence as a three-level framework makes our research task manageable while remaining theorydriven and systematic.

Thirdly，in the semiotic analysis of local coherence，the measurement of degree of information linking cannot be completely objective，especially that in the Reader Attraction stage.There is a certain degree of subjectivity although the principle provides a rough criterion for operation，although the limitation was mitigated by using more than one rater in this book.More efforts should be made in the future to seek for a solution for a more objective categorization and measurement of semantic connection between different semiotic modes.

Fourthly，in the empirical studies，there are two major limitations.The first one is that authentic natural materials instead of manipulated ones are used due to the exploratory nature of the experiments.The consequence is that we can only obtain correlation relations between textual resources and cognitive processes but not causal relationships.The other limitation is the small number of participants，which may have effects on the statistical analysis of the results.Future research should be made to overcome the methodological limitations and further clarify the relationship between the textual and cognitive aspects of coherence construction.

In terms of data，only print，static，two-dimensional advertisements are used in this book.This leaves out many other semiotic modes that are involved in three-dimensional and more digitally dependent genres concerning English learning，such as webpages and videos.These new ways of semiotic expressions，due to the quickly increasing use of technology in all kinds of communication，including the promotion of English learning，deserve serious research.Future efforts can be made to address the meaning-making across semiotic modes in these new genres of English learning in Chinese context.

Despite these inadequacies，this book is valuable for proposing a systematic framework for analyzing coherence in multimodal discourses，describing the ways of how visual and verbal elements are weaved into a whole on the basis of natural texts and providing empirical support for the theoretical assumptions through empirical methods.Future studies of visual-verbal relations in multimodal discourses can apply the findings in this book and explore the questions not considered in it，and combine the analytical tools and empirical methods with new tools for discourse analysis and discourse processing.