Much of the research described in this book was conducted during my PhD studies in Department of Linguistics and Translation， City University of Hong Kong， from 2012 to 2016. First and foremost， I would like to express my very great appreciation to my supervisor； Dr. Alex C. FANG， who guided and supervised this research. He inspired my interest in the topic dialogue act in interactive speech and promoted me into assessments by a large dialogue corpus， as discussed in this book. Assessment is one of the most crucial communicative， functions for language expression. It has attracted wide scholarly attention in recent exploration of language use. Various investigations of assessments at home and broad began in 1980s， diversified in terms of research perspectives， mainly concentrating on writing texts. In contrast， however， it has received little attention to assessments in spoken language and even fewer corpus-based investigations have been camed out. Therefore， it leaves this book plenty of discussion spaces for assessments in interactive dialogues based on corpus data.
　　Also， I would like to offer my special thanks to Dr. CAO Jing from Zhongnan University of Economics and Law， who provided many valuable suggestions and comments on an earlier draft. Her emphasis on corpus evidence had an important influence on my research. This book investigates how assessments are deployed in daily conversations by assessment utterances observed in Switchboard Dialogue Act （SwDA） Corpus. It aims to present a full picture of assessment utterances by empirical evidence， which could provide language knowledge and data for automatic recognition of assessments.
　　Credit must also go to Professor Harry Bunt of Tilburg Center for Cognition and Communication， Tilburg University， Professor Liu， Meichun and Dr. Suen Caesar Lun of Department of Linguistics and Translation， City University of Hong Kong， for their kindness and enlightening comments in the final exam.


    本書為“語言服務(wù)書系·話語研究”之一種，為中國博士后科學(xué)基金資助項(xiàng)目和山東省社會(huì)科學(xué)規(guī)劃研究項(xiàng)目的階段性成果。本書以經(jīng)過詞性標(biāo)注的Switchboard Dialogue Act Corpus（簡(jiǎn)稱SwDA）為數(shù)據(jù)基礎(chǔ)，考察英語日常對(duì)話中評(píng)價(jià)功能的語言使用特點(diǎn)，在評(píng)價(jià)功能與其使用特點(diǎn)間建立對(duì)應(yīng)關(guān)系。作者立足于英語對(duì)話語料庫，對(duì)評(píng)價(jià)功能的詞匯、句法結(jié)構(gòu)特點(diǎn)進(jìn)行全面、系統(tǒng)的考察，探索語言表達(dá)形式與交際功能的對(duì)應(yīng)關(guān)系，具有一定的創(chuàng)新性和學(xué)術(shù)研究價(jià)值。