The main reasons are as follows.
First, the author has a bad attitude. Some authors believe that as long as the research is done well, the quality of paper writing will be high, and it is superfluous to write another abstract. Some authors also believe that this is that theoretical workers are creating trouble for practical workers. In fact, this is because the author does not understand the role of abstraction. With a standardized abstract, readers can understand the paper quickly and accurately, which is helpful for the promotion of the paper.
Second, the author doesn't know the place. Is an important part of academic papers. However, some authors perfunctory, casually write a paragraph in the text, or write a few sentences before the text to make a summary, without spending energy, focusing on summarizing the full text, and without repeatedly scrutinizing the language, resulting in incomplete and inaccurate summary information, chaotic logical order, inaccurate language and other problems.
Third, the author's language organization and expression ability are low. Some authors also want to write a good abstract, but their language organization and expression skills are not strong enough to accurately and concisely summarize and summarize the essence or core of the full text. The verbosity and inaccuracy in language expression give people a sense of piling up, vague and general, and can not fully convey the main information of the full text.