It is generally divided into three levels: bachelor's thesis, master's thesis and doctoral thesis. Among them, the doctoral thesis is of the highest quality, which is an original scientific research work and the focus of collection and utilization. Dissertation represents different levels of knowledge and is one of the important sources of literature information.
Generally, it is not published in publications, and can only be obtained through degree-granting units, designated collection units and private channels. The retrieval tool for finding foreign dissertations is AB-STRACTS International, a dissertation edited and published by American University Microfilm Company.
Abstracts of dissertations from more than 450 universities in the United States, Canada, Britain, France, Belgium, Australia and other countries are collected and published in three series: A (Humanities and Social Sciences), B (Science and Engineering) and C (European Dissertation Abstracts).
China resumed the degree system in 1979. Beijing Library, China Institute of Science and Technology Information and Literature Information Center of Chinese Academy of Social Sciences are designated collection units for doctoral dissertations.
Degree thesis classification
Dissertations can be divided into bachelor's dissertations, master's dissertations and doctoral dissertations according to the degree applied.
According to the different research methods, the thesis can be divided into three categories: theoretical, experimental and descriptive. The research methods used in theoretical dissertations are theoretical proof, theoretical analysis and mathematical reasoning, through which scientific research results are obtained. The experimental paper uses experimental methods to carry out experimental research and obtain scientific research results;
Descriptive papers use the methods of description, comparison and explanation to study newly discovered things or phenomena and obtain scientific research results.
According to different research fields, dissertations can be divided into three categories: humanities academic papers, natural science academic papers and engineering technical academic papers. The text structure of these three kinds of papers is * * *, which has long-term use and reference value.