英语应用语言学论文写作定量数据分析.ppt

If you want to know the relative standing of any particular score in a group of scores, you can show it by a Percentile score.,陈雪茹 武静 2012/11/23,Definition,It can be defined as a number which represents the percent of scores that a particular raw score exceeds. 如果将一组数据从大到小排序，并计算相应的累计百分位，则某一百分位所对应数据的值就称为这一百分位的百分位数。,Formula,Cumulative frequency(累计频数) is the sum of all the frequencies up to and including that value. N represents the total number of scores.,Cumulative F Percentile = (100) N,Example of Percentile,For example, one student received a score in the 67th percentile on TOEFL, it means that 67% of students who took the test scored lower than that level. Or we say that his score is higher than 67% of the other people taking the test but lower than 33% of the people.,Example of Percentile,Selecting appropriate statistics,There are various statistics for you to choose from, you have to choose the most appropriate one to answer your research questions. There are four frequently used procedures in the Statistics menu of SPSS: Summarize, Compare means, Correlate and Regression. 在SPSS中的Statistics 菜单项中最常见的四种统计程序： Summarize(概括)，Compare means(比较均值), Correlate and Regression (回归)。除了Summarize外，所有统计程序 的运行都必须以正态分布的假设为前提。,Summarize(概括),When you open the Statistics menu, Summarize appears on the top of the list Which includes a variety of options. Only two options are explained here: Frequencies(频数统计) and Descriptives (描述性统计).,For example, if you want to know how many students are females and how manyAre males in a study, you can operate Frequencies.,We can see that there are 18 males occupying 23.4% and 59 females,76.6%.,Frequencies(频数统计),Descriptives (描述性统计),By descriptives, we can know what is the average score and what is the standard deviation of each category. 描述性统计告诉我们平均分和每个范畴的标准差。,Table: D