第5章抽样技术 Sampling Technology
第5章 抽样技术 Sampling Technology
基本抽样问题 基本概念 制定抽样计划的步骤 抽样误差与非抽样误差 概率抽样方法 非概率抽样方法
一、基本抽样问题 • 基本概念 • 制定抽样计划的步骤 • 抽样误差与非抽样误差 • 概率抽样方法 • 非概率抽样方法
本节概要(1) To understand the concept of sampling To learn the steps in developing a sampling pla an To understand the differences between probability samples and nonprobability samples To understand the concepts of sampling error and nonsampling error
本节概要（1） • To understand the concept of sampling. • To learn the steps in developing a sampling plan. • To understand the differences between probability samples and nonprobability samples. • To understand the concepts of sampling error and nonsampling error
本节概要(2) To review the types of probability sampling methods To gain insight into nonprobability sampling methods
本节概要（2） • To review the types of probability sampling methods. • To gain insight into nonprobability sampling methods
基本概念 Population(总体) The total group of people from whom information is needed Census(普查) Data obtained from or about every member of the population of interest Sample(样本) A subset of the population of interest
基本概念 • Population（总体） – The total group of people from whom information is needed. • Census（普查） – Data obtained from or about every member of the population of interest. • Sample（样本） – A subset of the population of interest
Steps in Developing a Sample plan 设计一个抽样方案的步骤 Step 7: Execute Step 2: Choose Operational Sampling Data collection Plan Method Step 1: Define the Step 3: Choose Step 6: Develop and Population of Sampling frames Specify Operational Interest Plan Step 5: Determine Step 4: Select a ample size Sampling method
Steps in Developing a Sample Plan 设计一个抽样方案的步骤 Step 1: Define the Population of Interest Step 2: Choose Data Collection Method Step 3: Choose Sampling Frames Step 4: Select a Sampling Method Step 5: Determine Sample Size Step 6: Develop and Specify Operational Plan Step 7: Execute Operational Sampling Plan
Steps in Developing a Sampling Plan (1) Step 1: Defining the Population of Interest Bases for defining the population of interest nclude Geography Demographics ● Awareness
Steps in Developing a Sampling Plan （1） • Step 1: Defining the Population of Interest – Bases for defining the population of interest include: • Geography • Demographics • Use • Awareness
Steps in Developing a Sampling Plan (2) Step 2: Choosing a Data Collection Method The selection of a data collection method has implications for the sampling process Step 3: Choosing a Sampling frame Sampling frame List of population elements from which to select units to be sampled
Steps in Developing a Sampling Plan （2） • Step 2: Choosing a Data Collection Method – The selection of a data collection method has implications for the sampling process. • Step 3: Choosing a Sampling Frame – Sampling frame • List of population elements from which to select units to be sampled
Steps in Developing a Sampling Plan (3) Step 4: Selecting the Sampling Method Probability samples Samples in which every element of the population has a known, nonzero probability of selection. Nonprobability samples Include the selection of specific elements from the population in a nonrandom manner
Steps in Developing a Sampling Plan （3） • Step 4: Selecting the Sampling Method – Probability samples • Samples in which every element of the population has a known, nonzero probability of selection. – Nonprobability samples • Include the selection of specific elements from the population in a nonrandom manner
Steps in Developing a Sampling Plan (4) Step 4: Selecting the Sampling Method (continued Sampling error: The difference between the sample value and the true value of the population mean ↓3L
Steps in Developing a Sampling Plan （4） • Step 4: Selecting the Sampling Method (continued) – Sampling error: The difference between the sample value and the true value of the population mean