研究生统计学课件--第1章绪论(E).pptVIP

第1章 绪论 END 第1章 绪论 * 研究生用《医学统计学》教 案 第1章 绪论 * Medical Statistics English Teaching Plan for Medical Graduate Students 第1章 绪论 * Chapter 1 Introduction Statistics: Statistics is a way to get information from data. It may be divided into two types. Descriptive statistics deal with methods of organizing,summarizing,and presenting data in a convenient and informative way. Inferential statistics is a body of methods used to draw conclusions or inferences about characteristics of populations based on sample data. 第1章 绪论 * Population （总体） A population is any entire collection of people, animals, plants or things from which we may collect data. It is finite (有限) or infinite（无限） population. 同质的所有观察单位某种观察值的集合。 个体：individule Parameter（参数） A descriptive measure of a population is called a parameter. Sample （样本）sampling A sample is a set of data from a population . 第1章 绪论 * Statistic(统计量) A descriptive measure of a sample is called statistic. Types of data A variable(变量)is some characteristic of a population or sample.z总体或样本的某些特征 The values(取值) of the variable are the possible observations of the variable. The data (资料或数据) are the observed values of the variable .由变量值构成 第1章 绪论 * There are three types of data. They are interval（区间）,nominal（名义）,and ordinal（顺序） data. Interval data(区间资料)are real numbers, such as heights,weights,incomes,and distance. We also refer to this type of data as quantitative（计量） or numerical（数值）.即计量资料measurement data或数值变量numerical variable. Nominal data名义资料 are also called qualitative data(定性资料)或计数资料(enumeration count data). ( 属性的) or categorical（分类的）. 第1章 绪论 * For example,marital (婚姻)status produce nominal data.(名义资料). Ordinal data(顺序资料) appear to be nominal, but their values are in order. For example,students are asked to evaluate the course(课程),the values are: Poor,fair,good,very good, and excellent. 第1章 绪论 * CALCULATIONS ON TYPES OF DATA Nominal data All calculations are permitted on interval data. Nominal data Because the codes of nominal data are