統(tǒng)計語言學(xué)教案(全英文版)

1、Statistics in LinguisticsSyllabusSyllabusSyllabus SyllabusAssessmentn30% classroom participationn70% final examCourse Booksn李紹山，2001，語言研究中的統(tǒng)計學(xué)，西安：西安交通大學(xué)出版社。nButler, C. 1985. Statistics in Linguistics. New York: Basil Blackwell.nWoods, A., Fletcher, P. & Hughes, A. 1986. Statistics in Language St

2、udies. Cambridge: Cambridge University Press.ReferencesnBrown, J. D. 1988. Understanding Research in Second Language Learning. Cambridge: Cambridge University Press.nBrown, J. D. 2002. Doing Second Language Research. Oxford: Oxford University Press.nHatch, E. & Lazaraton, A. 1991. The Research M

3、anual: Design and Statistics for Applied Linguistics. New York: Newbury House Publishers.nHinton, P. 2004. Statistics Explained. London: Routledge.nMuijs, D. 2004. Doing Quantitative Research in Education with SPSS. London: Sage Publications.Statistical SoftwarenSPSS (Statistical Package for the Soc

4、ial Sciences)nExcel1. IntroductionNeed for statistics in linguisticsReasonsnIn language study, many kinds of work require the collection and analysis of quantitative data. Statistics turns the raw data into meaningful information for decision-making.nIn terms of research methods, articles of an argu

5、mentative, or speculative nature are not convincing.“個人經(jīng)驗(yàn)與看法”在四個刊物中的總體比例從1978年的32%下降到1997年的12%（高一虹 等，1992）。nSome knowledge of statistics will make us understand academic articles better.n量化研究呈上升趨勢，現(xiàn)代外語的量化研究在80年代中才出現(xiàn)，到90年代經(jīng)常在20%-30%之間，從1997年第三期改版以來，量化研究的比例達(dá)到50%；外語教學(xué)與研究在80年代基本上徘徊在10%上下，而90年代基本上在30%-40

6、%之間。（選自高一虹等，1999）Reasons2. Describing VariablesPopulations, Samples, and Random SamplingnPopulation(總體）nAny collection of entities, of whatever kind, that is the object of investigation (Butler, C. Statistics in Linguistics, 1985)nfinite population: the number of entities is fixed and countable（有限總體

7、）ninfinite population: the number of entities is potentially infinite，at least in theory（無限總體）nSample （樣本）nEntities selected from a population for investigation Populations, Samples, and Random SamplingnSampling （抽樣）nThe process of selecting/drawing samples （樣本） from the population concernednReasons

8、 for sampling 1)For infinite populations, it is impossible to make exhaustive investigations; for finite populations in which the number of entities is too large, exhaustive investigations are theoretically possible but impracticable. 2) Sampling cuts down the labor, time and cost involved in obtain

9、ing data. 3) Sampling minimizes the errors that can be easily made during the processing of large numbers of statistical data.By sampling, we hope that the results obtained from the sample will be generalisable to the population. 總體、樣本和隨機(jī)抽樣n總體n作為研究對象的任何個體的集合或目標(biāo)群體（李紹山，2008）n樣本n從總體中抽取的用以研究的一部分個體n隨機(jī)抽樣n

10、抽簽n隨機(jī)數(shù)表n計算機(jī)生成的隨機(jī)數(shù)字 系統(tǒng)隨機(jī)抽樣（或準(zhǔn)隨機(jī)抽樣） 團(tuán)體抽樣n分層隨機(jī)抽樣： 比例分層隨機(jī)抽樣、非比例分層隨機(jī)抽樣n多級抽樣總體抽樣框架隨機(jī)抽樣Populations, Samples, and Random Samplingnrandom sampling(隨機(jī)抽樣): every unit (entity) in the population has an equal chance of being represented in the sample(總體中的每個個體有同等的機(jī)會在樣本中得到體現(xiàn)，即總體中的每個個體被抽中的概率是相同的。）ndrawing: simple r

11、andom samplingnrandom digits tablenrandom digits generated by computer (Excel) Variation: systematic /quasi-random sampling Variation within systematic sampling: block samplingnstratified random sampling proportional stratified random sampling disproportional stratified random samplingnMulti-stage s

12、amplingPopulationSampling frameRandom samplingPopulations, Samples, and Random SamplingnRandom samplingnVariation of simple random sampling:Variation of simple random sampling: systematic /quasi-random samplingsystematic /quasi-random samplingThe first unit in the sample is selected by truly random

13、methods, and then the other units are taken at equal intervals throughout the numbered population, the intervals being taken to give the desired number in the final sample. (interval=number of population/size of sample)nNot truly random, since the second and subsequent units in the sample are not se

14、lected truly independently of the first unit. This does not matter seriously if there is no periodicity in the population.Populations, Samples, and Random SamplingnRandom samplingnVariation of simple random sampling:Variation of simple random sampling: systematic /quasi-random samplingsystematic /qu

15、asi-random samplingnVariation within systematic sampling: block samplingVariation within systematic sampling: block sampling The position of the beginning of the sample is determined randomly, but the next N items are taken, where N is the size of the sample.nThe position of the beginning of the sam

16、ple is determined randomly, but the next N items are taken, where N is the size of the sample.nThe true randomness of such a sample is not guaranteed.nIt is important to realize that the selection of a sample by methods designed to achieve true randomness does not guarantee that the sample arrived a

17、t will indeed be representative of the population.nProbability (Butler, C. Statistics in Linguistics, 1985 :7) Populations, Samples, and Random SamplingPopulations, Samples, and Random SamplingnRandom samplingnstratified random sampling:stratified random sampling: stratum-strata-stratify If the vari

18、ous subgroups (strata) in the population are known, then random sampling can be undertaken with each stratum, and the resulting subsamples can be combined to give an overall sample.nproportional stratified random sampling:proportional stratified random sampling: The proportion of each subsample in t

19、he overall sample is equal to the proportion of each stratum in the population. It enables a stratum that has a small overall proportion in the population to be represented in the sample and allows comparisons to be made between the subsamples. ndisproportional stratified random sampling:disproporti

20、onal stratified random sampling: The proportion of each subsample in the overall sample is not equal to the proportion of each stratum in the population. It provides the optimal condition for comparisons to be made. Populations, Samples, and Random SamplingnRandom samplingnmulti-stage sampling: nThe

21、 sampling is undertaken by successive stages, treating the sample at one stage as the population for the next stage 目前我國高校英語專業(yè)包括?？圃趦?nèi)有1000多個辦學(xué)點(diǎn)最多的每年招收1000多名學(xué)生（王金生，朱黎輝，2008：45），其中本科英語專業(yè)教學(xué)點(diǎn)600多個，這其中有200多個設(shè)置在理工類院校（秦秀白，2006）。Populations, Samples, and Random Samplingx Population parameter(參數(shù)） vs. sample s

22、tatistic（統(tǒng)計量） parameter: one of the properties of a population, symbolized by Roman letters or English letters (李紹山, 2008) statisitc: one of the properties of a sample, symbolized by Greek lettersPopulations, Samples, and Random Samplingpopulation parametersample statistic/estimate(估計值）meanvariances

23、tandard deviationcorrelationx22ssr總體、樣本和隨機(jī)抽樣n總體參數(shù) vs. 樣本統(tǒng)計量 Population Sample Parameter Statistic平均數(shù) 方差 2 s2標(biāo)準(zhǔn)差 s相關(guān)系數(shù) rxHomework 1n1. Define the following terms with an example.n 1) population 2) sample n2. Why should we be content with a sample for our study in most cases?n3. What is random samplin

24、g? Why should we select a sample randomly?n4. 假如一所學(xué)校有15個系，每個系由20個自然班，每個班有25人左右，共7300人。要從中選取一個100人的樣本，那么：n 1）最好用什么方法進(jìn)行抽樣？為什么？請說出具體步驟。n 2）如果要保證樣本中男、女生各占一半，又如何進(jìn)行抽樣？n 3）試用隨機(jī)數(shù)表以簡單隨機(jī)抽樣的方式從7300名學(xué)生中選取 該樣本。Variables Variable ： an attribute (屬性） of a person, a piece of text, or an object, which varies from pe

25、rson to person, text to text, object to object, or from time to time. In statistics, variables refer to measurable attributes, as these typically vary over time or between individuals. (From Wikipedia)Variables In a research project, we may wish to look at levels(水平） within a variable. For example,

26、we might want to know how well ESL students are able to do some task. If the study is designed to compare the performance of ESL students who are foreign students with the performance of those who are immigrant students, then the variable is the circumstance in which the ESL students learn English,

27、and it will have two levels. If the study is concerned with geographic area, i.e. if the study is to compare the performance of students from different areas, then the variable is geographic area, and there might be such levels as South American, European, Middle Eastern, or Asian so that comparison

28、s among these levels of ESL student can be made. The variable would consist of four levels. Or, for the purposes of the study, we might want to know if there is a difference in performance between advanced, intermediate, and beginner ESL students. The variable, then, is the proficiency level, which

29、has three levels.The variable is ESL student. That variable may be divided into levels for the purposes of the study.(?)Variables nClassification of variablesnaccording to the function a variable has in a study independent variable & dependent variable naccording to the level of measurement nomi

30、nal variable, ordinal variable, interval variable & ration variablenAccording to whether data obtained on a variable is continuous or not continuous variable & discrete (discontinuous) variableVariablesnclassification of variablesnaccording to the function a variable has in a study independe

31、nt variable & dependent variablenindependent variable(自變量）: variable that the investigator deliberately manipulates/ variable that the investigator can vary - IVndependent Variable（因變量）: variable whose response to the IV the investigator is measuring-DV Variablesnclassification of variablesnacco

32、rding to the level of measurement nNominal variable(名稱變量/稱名變量): purely qualitative, not quantitative. Entities may be the same or different, but not “more” or “l(fā)ess”.nNaming, not measurement, no arithmetic valuensex, social status, mother tongue ,marital status according to the level of measurement

33、nOrdinal variable(順序變量): rank the values of the entities on a scale of “more” or “l(fā)ess”. The value of one entity may be more or less, higher or lower than that of another entity.nOrdering, cant tell the size of the differencenVery impoliteimpolitepolitevery politenThe lessons are boring 1 2 3 4 5 6

34、7 8 9 nhave arithmetic value, but the value is not precisenClass rank：1289Variablenclassification of variablesnaccording to the level of measurementnInterval variable(等距變量）nThere are truly equal intervals between points on the scale of “more” or “l(fā)ess”.nTest scores：95907065nTemperatures:nRatio varia

35、ble（比率變量）: there is an absolute zero in the variable, and ratios may be taken.nHave an absolute zero point: height, time, distance, but not temperature(絕對零度-273.15攝氏度)nSeldom used in linguistic studiesVariablesnClassification of variables naccording to the level of measurement It is very important f

36、or investigators to know which type of variable they are dealing with, because different statistical procedures are appropriate for different types of variable. The level of measurement of a variable influences the choice of a measure of central tendency and variability, and influences the choice of

37、 procedures for hypothesis testing. Parametric tests are used for ratio and interval variables; non-parametric tests are used for nominal and ordinal variables.n英語期末考試分?jǐn)?shù)數(shù)據(jù)的變化：Variable IntervalOrdinalnominalStudents rankgroupingTest scoreHigh group, low groupranksVariablesnClassification of variables

38、nAccording to whether data obtained on a variable is continuous or not Continuous variable(連續(xù)變量）: may take any value within a given rangenFor a continuous variable, there are an infinite number of possible values that can fall between any two observed values. It is divisible into an infinite number of fractional parts, e.g. test scores, time