英语翻译1、Random sampling （in large numbers）provides the best chance ofan unbiased representative sample of a target population.2、A deliberate effort is made to identify the characteristic of a sample most important for it to be represent

英语翻译1、Random sampling （in large numbers）provides the best chance ofan unbiased representative sample of a target population.2、A deliberate effort is made to identify the characteristic of a sample most important for it to be represent
英语翻译
1、Random sampling （in large numbers）provides the best chance ofan unbiased representative sample of a target population.
2、A deliberate effort is made to identify the characteristic of a sample most important for it to be representative of the target population.
3、It is quick,convenient and often the most economicalmethod of sampling.
It has,therefore,been the most common type of sampling.
4、Self-selecting samples are relatively convenient and,if volunteering is made on thebasis of informed consent ,ethical.
1、The larger the target population ,the more difficult it is to sample randomly ,since compiling a selection list ofeveryone becomes more impractical.Ture random sampling is,therefore,very rare.
2、Stratified sampling can be very time consuming,since the subcategories have to
be identified and their proportions in the target population calculated.
3、Opportunity sampling gives very unrepresentative samples and is
often biased on the part of the researcher who may choose subjects who
will be “helpful”.
4、Self-selecting samples are often unrepresentative – being biased on the part of the subject.Volunteers are unlike nonvolunteers in many ways.

英语翻译1、Random sampling （in large numbers）provides the best chance ofan unbiased representative sample of a target population.2、A deliberate effort is made to identify the characteristic of a sample most important for it to be represent
1、随机抽样（在足够大量）为一个不带偏见目标人群的代表性样本提供了最大的可能.