Apparently, by adding a question in the title. See this report and this article.

Title of an article can be descriptive, declarative or a question. It plays important role in both marketing and findability of article. We investigate the impact of the type of article titles on the number of citations and downloads articles receive. Number of downloads and citations for all articles published in six of PLoS (Public Library of Science) journals (2,172 articles) were obtained from PLoS and type of each article’s title (including descriptive, indicative and question) was determined as well as the number of substantive words in title (title length). Statistical difference and correlation tests were carried out. The findings showed that differences exist between articles with different types of titles in terms of downloads and citations, especially articles with question titles tended to be downloaded more but cited less than the others. Articles with longer titles were downloaded slightly less than the articles with shorter titles. Titles with colon tended to be longer and receive fewer downloads and citations. As expected, number of downloads and citations were positively correlated.