3.School C
　　Unlike the other two national key schools - School A and SchoolB，School C（a tourism school）is only a provincial key school.Theschool covers an area of 55，000 square meters.The featuredspecialties of the schoolare tourism service andmanagement，pre-school education，and hotel serviceand management.Theschool is the specified tourism guide training centerfor both thecity and the province，the advanced chef training center forthe cityand a vocational skill certified center.The school has somewell-eqrupped simulated training classrooms for service sectororiented students，such as the simulated Chinese and Western dininghalls，the simulatedtea house，the simulated mini bar，the simulatedguest room，the cookingoperation room，the dance hall and thephysical training room.In additionto the various vocationaltraining rooms，the school also has a library，a multimedia computerroom and other moderntechnological facilities.
　　Among its 191 teaching staff，12 are provincial vocational sHIlcertifiedteachers，15 are national tourism guide holders and fiveare expert chefs.Inaddition to the school's full-time teachingstaff，the school also invites midlevel managers from the hotelindustry or tourism industry to come to the school to teach anddevelop vocational-oriented curriculums.Like School A，School C hasalso signed contracts with enterprises in the service industry，inparticular with travel agents from within and outside theprovince.As a service-oriented school，English has always been animportant feature of theschool's agenda.
　　On both sides of the corridor hang the pictures of famousbusinessmen and their sayings.During my school visits，I found somestudents wanderingaround in the corridor during class time andcaught sight of some cigarette butts in the ground-floor corner inmy pilot study.
　　In general，each of-the three schools has its own specialcharacteristicsand particular specialties，with two beingservice-orientated and onemanufacturing-orientated.
　　4.2.5.2.2 Samplirig
　　As Miles and Huberman state，"As much as you might wantto，youcannot study everyone everywhere doingeverything"（1994，p.27）.Samplingis crucial especially in doingNA（Brown，1995）.Choices must be made interms of”whom to look at ortalk with，where，when，about what，and why——all place limits on theconclusions you can draw，and on how confident youand others feelabout them.Even when the boundary of a case（e.g.，a schoolin thisstudy）is defined，there are still settings within settings in eachschool.The school has classrooms，the classrooms have teachers andstudentsteaching and learning within them.And the questions ofmultiple-casesampling add another layer ofcomplexity"（ibid.）.
　　In qualitative research，sampling usually involves two actions：boundarysetting and frame creation（Miles &Huberman，1994，p.27）.In terms ofsamplingstrategies，Erickson（1986）suggests a generic，funnelingsamplingsequence，working from the outside into the center of asetting."Within-case sampling is almost always nested...withregular movement up anddown that ladder"（Miles &Huberman，1994，p.29）.Following the theoryand strategies mentionedabove，a purposive stratified random'samplingwithin-case frameworkwas set with the order of selection criteria extendingfrom theperipheral to the core of the setting due to the complexity ofthephenomena，with the use of multiple purposive techniques（Teddlie& Yu，2007）.
　　Purposive sampling（Miles & Huberman，1994）or purposefulsamplingleads to greater depth of information from a smaller numberof carefullyselected representative cases（Patton，2002）from thequantitative study.Results from the quantitative phase produced ageneral picture of thestudents'general demographic information andtheir language achievement.On the basis of the data analysis of thefirst phase quantitative study，within-case participants wereselected with reference to the teacher's commentsand theresearcher's classroom observations.The advantage of multiple-casestratified random purposive sampling can strengthen theprecision，the validity，and the stability of the qualitativestudy（Long，2005c;Miles &Huberman，1994）.Table 4.9 shows thedetailed multiple-case samplingprocedure.
　　……