Generally speaking, according to the regulations, the paper selects 3 ~ 8 keywords. According to the statistical results of periodicals, 3 keywords and 4 keywords each account for 40%, and the rest use 5 or more keywords. According to the papers of an international conference, it is found that four keywords are the most, accounting for more than 50%. Therefore, it is suggested to use four keywords. At the same time, the keywords are separated by semicolons, and finally there is no punctuation.

Keywords are generally selected from titles and abstracts. The first two keywords generally define the research field or research object. For example, there are 1 papers on automatic monitoring of infrared alarms in museums. You can choose the first two keywords: "museum, alarm", and the last two keywords generally choose research means and methods. For example, the four keywords "infrared sensor, single chip microcomputer" in the above example basically cover the main fields of the paper, and readers can easily retrieve the author's paper from all angles. For example, if the author chooses "single chip microcomputer, programming, display and automation", the main content of the paper can't be well reflected.

Be careful not to use too general keywords, such as "circuit", "device", "system", "analysis" and "measurement", which are not specific. Can't use too trivial details, readers may not think of using such keywords to search.