大家要将听力全文听写哦！同时本文将附上译文希望能帮助大家理解。加油吧！！

 

Hints

Ways to select samples in research

--time sampling

---systematic: fixed intervals every hour

---random: ____ （填空不写）

 

Now, as you remember, the primary goal of observation is to describe behavior, but it is in reality impossible to observe and describe all of a person's behavior. So we have to rely on observing samples of people's behavior. Doing so, we must decide whether the samples represent people's usual behavior. Thus, we will first take a brief look at how researchers select samples of behavior. Before conducting an observational study, researchers must make a number of important decisions, that's about when and where observations will be made. As I've said before, the researcher cannot observe all behavior. Only certain behaviors occurring at particular times, in specific settings can be observed. In other words, behavior must be sampled. In this lecture, I will briefly introduce two kinds of sampling,that is, time sampling and situation sampling. Now first, time sampling. Time sampling means that researchers choose various time intervals for their observation. Intervals may be selected systematically or randomly. Suppose we want to observe students' classroom behavior. Then in systematic time sampling, our observations might be made during five 20-minute periods, beginning every hour. The first observation period could begin at 9 am, the second at 10 am and so forth.
现在,正如你所想,观察的主要目的是描述行为。但是在现实中我们无法观察和描述一个人的所有行为，所以我们必须依靠于观察他人的行为样本。要这样做,我们必须判定这些样本是否能够代表人们的日常行为。因此,首先我们来简要地看一看研究者是如何选择行为样本的。在进行一项观察性研究之前,研究人员必须做出很多重要的决定,即在什么时候、什么地方进行观察。就像我之前说的,研究者不能观察到所有行为。某些行为只有发生在特定的时间以及在特定的情况下才可以观察的到。换句话说,行为必须抽样。本次讲座,我将简要介绍两种抽样方法,即时间抽样和情况抽样。第一、时间抽样。时间抽样是指研究人员在不同的时间间隔进行观察。他们可以系统地选择时间间隔也可以随机地选择时间间隔。假设我们要观察学生的课堂行为。那么，在系统时间抽样中,我们可以在5个20分钟的时间段内进行观察,每隔一小时开始。第一个观察期间可以在上午9点开始,第二个观察期间在上午10点开始，等等。 翻译by：sugarle