3.5 Softwares Used
One major tool used in the book isW ordsmith 7.0（Scott 2016）.The software has three major toolbars：Concord，KeyW ords and Word list.W ordlist can list words either in terms of frequency or alphabet.Meanwhile，statistics（including file size，type／token ratio（TTR），standardized TTR，word length，sentence length and so on）will be presented.KeyW ords can be used to calculate the keyness between OETT and TETT.Overused and underused words are represented clearly with either log-likelihood or chi-square value.Concord is used for KW IC（keywords in context）analysis which can show the actual use of words in context.
Antconc 3.5.8 is another tool frequently used in the book，the functions of which are similar with Wordsmith 7.0.Because of simplicity and convenience，it is especially used for KW IC analysis and regular expression retrieval.
RANGE32[2]is a software program to test readability.The basewords of BNC（British National Corpus）and GSL＆AW L（the general service list and the academic word list）are taken as the examiner of the readability in tourism texts.
Ialso use Log-likelihood calculator[3]to reveal the distance between the observed and the expected，that is，which word is overused or underused in the“analysis corpus”and“reference corpus”.(https://www.daowen.com)
Table 3.1 Log-likelihood Value and Odds
Table 3.1 lists some of the LL value，P（probability）value and odds.The higher the LL value is，themore significant is the difference between two frequency scores.
SPSS（Statistical Product and Service Solutions）is a powerful statistical software product.It is used for factor analysis in Chapter Four.