a set of ideas intended to explain the reason behind the existence or occurrence of something
理论, 学说
the process or action of carefully watching a thing or person, often for learning something about them
观察, 察看
a careful and systematic study of a subject to discover new facts or information about it
研究, 调查
anything that proves the truth or possibility of something, such as facts, objects, or signs
证据, 证明
a methodical examination of the whole structure of something and the relation between its components
分析, 系统检查
a specific way or process of doing something, particularly an established or systematic one
方法, 途径
a randomly selected part of a larger group, put to study in order to gain knowledge or to draw conclusions about the larger group
样本, 随机样本
a printed work, such as a book, magazine, etc. that is publicly distributed
出版物, 印刷品
a paper containing a series of questions that is given to people to collect information for statistical reasons
问卷, 调查表
a book or a document that supplies information in a research and is referred to
来源, 参考文献
an inspection of opinions or experiences of a specific group of people that is usually done in the from of questions
调查, 问卷