a set of ideas intended to explain the reason behind the existence or occurrence of something

理论, 假说
a brief summary that presents the key points of a book, speech, etc.

摘要, 提要
the process or action of carefully watching a thing or person, often for learning something about them

观察, 观测
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, 剖析
a specific way or process of doing something, particularly an established or systematic one

方法, 方式
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, 抽样
a paper containing a series of questions that is given to people to collect information for statistical reasons

问卷, 调查表
data and information that can be gathered to form a research

材料, 资料
