三步教你轻松搞定Sampling Method解题辨析！

      Step 1: 看到题目，仔细分析题干，标出关键字

 

      Step 2: 题目要求选出的是false，然后看各可选内容：

 

       (i)A simple random sample is a sample selected in such a way that every item in the population has an equal chance of being included.

 

      If a sample is selected using random sampling, it will be free from bias (since every item will have an equal chance of being selected). Once the sample has been selected, valid inferences about the population being sampled can be made.

 

      所以，符合random sampling， (i) is correct.

 

      (ii)A sampling frame is a numbered list of all items in a population. 

 

      Sampling frame 名单抽样框：列出所有在总体中的项目名单，并依次编号。

 

      注意Sample（样本）是在population（总体）中抽出来的，此处概念错误。

 

      所以，(ii) is false.

 

      (iii)Cluster sampling 整群抽样

 

      Cluster sampling is a non-random sampling method that involves selecting one definable subsection of the population as the sample, that subsection taken to be representative of the population in question.

 

      Cluster sampling是非随机抽样，方法是选定一个具有代表性的群体作为样本，来解释总体。

 

      比如，调查全国在校小学生情况，Cluster sampling方法是：选定某所学校的小学生进行调查，将该校小学生的调查情况（sample）来代表全国在校小学生的情况（population）。

 

      这种方法的disadvantage是There is potential for considerable bias，而不是选项所述的very little potential for bias。

 

      所以，(iii) is false.

 

      (iv)In quota sampling, randomness is forfeited in the interests of cheapness and administrative simplicity.

 

      Investigators are told to interview all the people they meet up to a certain quota. 这是quota sampling运作方式，只要是调查者遇见的人，即可作为一个样本进行采访，直到采访到指定的样本量。比较常见的例子是市场调查，如商业街上的产品问卷调查。

 

      所以，（iv） is correct.

 

      Step 3: 综合分析，进行选择，注意是选false！

 

      看完上面的小技巧是不是发现解题思路和步骤很重要？以前不知道没关系，现在开始养成好习惯吧！希望这个解题法能对小伙伴们有帮助！最后小编预祝各位考生考试顺利！