In brief words, back translation can be defined as the procedure according to which a translator or team of professional translators interpret a document previously translated into another language back to the original language. Usually this process is made by a translator or translators who had not been previously involved in the project and who have no prior knowledge of the objectives or its specific context.

The process of back translation is especially useful for professional translators who wish to ensure the most absolute quality and accuracy to their clients. Despite taking extra time, back translation as performed by translation services is an excellent way of avoiding errors later on during the decision-making process.

A Likert scale (/ˈlɪk.ərt/ LIK-ərt[1] but commonly mispronounced /ˈlaɪ.kərt/ LY-kərt[2]) is a psychometric scale commonly involved in research that employs questionnaires.

It is the most widely used approach to scaling responses in survey research, such that the term (or more accurately the Likert-type scale) is often used interchangeably with rating scale, although there are other types of rating scales.

When responding to a Likert item, respondents specify their level of agreement or disagreement on a symmetric agree-disagree scale for a series of statements. Thus, the range captures the intensity of their feelings for a given item.

The scale is named after its inventor, psychologist Rensis Likert.[3] Likert distinguished between a scale proper, which emerges from collective responses to a set of items (usually eight or more), and the format in which responses are scored along a range. Technically speaking, a Likert scale refers only to the former.[4] The difference between these two concepts has to do with the distinction Likert made between the underlying phenomenon being investigated and the means of capturing variation that points to the underlying phenomenon.

A scale can be created as the simple sum or average of questionnaire responses over the set of individual items (questions). In so doing, Likert scaling assumes distances between each choice (answer option) are equal.

A Likert scale is the sum of responses on several Likert items. Because many Likert scales pair each constituent Likert item with its own instance of a visual analogue scale (e.g., a horizontal line, on which a subject indicates his or her response by circling or checking tick-marks), an individual item is itself sometimes erroneously referred to as being or having a scale, with this error creating pervasive confusion in the literature and parlance of the field.

1使用量表的目的
在问卷设计中常把量表题设计为核心题项，原因是量表题可以将被调查者的回答转换成数字用于编码。经过量化处理后的数据，更方便进行统计分析，相比非量表题，可以使用更多的分析方法，得到更精确的分析结果

2量表类问卷的设计框架
正是由于上述原因，量表题已被广泛的应用于各类问卷之中，包括影响关系研究，中介或者调节作用检验，指标权重计算，细分市场研究等。量表类问卷从设计结构上看可以分为六部分，分别是筛选题项，样本基本背景信息题项，样本特征信息题项，样本基本态度题项，核心研究变量题项和其它题项等。

https://zhuanlan.zhihu.com/p/60582045

LZ.可以请教一个问题嘛？为什么有些ARMA模型不能进行LM检验（eviews显示“Not available with this estimation method (ARMA ML)啊？