Not necessarily. From the content of the paper, the author can extract keywords from the topic and the paper.

1. Excerpt from the title of the paper: The title of the scientific paper contains the main information points of the paper, such as the research object and research methods. Therefore, the selection of keywords should first consider the selection from the title.

2. Excerpts from papers: Sometimes the titles of scientific papers are general and cannot fully reflect all the contents expressed in the papers. If you only select keywords from the title, you will not only fail to reach the specified number of keywords, but also lose some information. When extracting keywords, the author of the paper can analyze the theme of the document, find out the theme concept and central content of the paper, and extract words and phrases consistent with the theme concept from the title, abstract, hierarchical title and important paragraphs of the text as much as possible, so as to extract the keywords of the paper.

3. For the application of words, the author can extract keywords from the transformed concepts and applied vocabulary.