Chinese Pinyin input method is very important for Chinese language information processing . Users may make errors when they are typing in Chinese words . In this paper , we are concerned with the reasons that cause the errors . Inspired by the observation that pressing backspace is one of the most common user behaviors to modify the errors , we collect 54 , 309 , 334 error-correction pairs from a realworld data set that contains 2 , 277 , 786 users via backspace operations . In addition , we present a comparative analysis of the data to achieve a better understanding of users ' input behaviors . Comparisons with English typos suggest that some language-specific properties result in a part of Chinese input errors . Unlike western languages , Chinese is unique due to its logographic writing system . Chinese users can not directly type in Chinese words using a QW-ERTY keyboard . Pinyin is the official system to transcribe Chinese characters into the Latin alphabet . Based on this transcription system , Pinyin input methods have been proposed to assist users to type in Chinese words ( Chen , 1997 ) . The typical way to type in Chinese words is in a sequential manner ( Wang et al . , 2001 ) . Assume users want to type in the Chinese word " 什 么(what ) " . First , they mentally generate and type in corresponding Pinyin " shenme " . Then , a Chinese Pinyin input method displays a list of Chinese words which share that Pinyin , as shown in Fig . 1 . Users visually search the target word from candidates and select numeric key " 1 " to get the result . The last two steps do not exist in typing process of English words , which indicates that it is more complicated for Chinese users to type in Chinese words . Chinese users may make errors when they are typing in Chinese words . As shown in Fig . 2 , a user may mistype " shenme " as " shenem " . Typical Chinese Pinyin input method can not return the right word . Users may not realize that an error occurs and select the first candidate word " 什恶魔 " ( a meaningless word ) as the result . This greatly limits user experience since users have to identify errors and modify them , or can not get the right word . In this paper , we analyze the reasons that cause errors in Chinese Pinyin input method . This analysis is helpful in enhancing the user experience and the performance of Chinese Pinyin input method . In practice , users press backspace on the keyboard to modify the errors , they delete the mistyped word and re-type in the correct word . Motivated by this ob-servation , we can extract error-correction pairs from backspace operations . These error-correction pairs are of great importance in Chinese spelling correction task which generally relies on sets of confusing words . We extract 54 , 309 , 334 error-correction pairs from user input behaviors and further study them . Our comparative analysis of Chinese and English typos suggests that some language-specific properties of Chinese lead to a part of input errors . To the best of our knowledge , this paper is the first one which analyzes user input behaviors in Chinese Pinyin input method . The rest of this paper is organized as follows . Section 2 discusses related works . Section 3 introduces how we collect errors in Chinese Pinyin input method . In Section 4 , we investigate the reasons that result in these errors . Section 5 concludes the whole paper and discusses future work . In this paper , we study user input behaviors in Chinese Pinyin input method from backspace operations . We aim at analyzing the reasons that cause these errors . Users signal that they are very likely to make errors if they press backspace on the keyboard . Then they modify the errors and type in the correct words they want . Different from the previous research , we extract abundant Pinyin-correction and Chinese word-correction pairs from backspace operations . Compared with English typos , we observe some language-specific properties in Chinese have impact on errors . All in all , user behaviors ( Zheng et al . , 2009 ; Zheng et al . , 2010 ; Zheng et al . , 2011b ) in Chinese Pinyin input method provide novel perspectives for natural language processing tasks . Below we sketch three possible directions for the future work : ( 1 ) we should consider position features in analyzing Pinyin errors . For example , it is less likely that users make errors in the first letter of an input Pinyin . ( 2 ) we aim at designing a selfadaptive input method that provide error-tolerant features ( Chen and Lee , 2000 ; Zheng et al . , 2011a ) . ( 3 ) we want to build a Chinese spelling correction system based on extracted error-correction pairs .

Challenge: The logographic writing system in Chinese makes the typing process with a QWERTY keyboard more complicated than in English limiting user experience.
Approach: They build large Chinese error-correction pairs by exploiting the action of pressing the backspace key and perform analysis to understand users' input behaviors.
Outcome: Comparative input-error analysis between Chinese and English shows that there are languages specific error types only happen in Chinese.