Google Scholar's Ranking Algorithm: The Impact of Articles' Age (An Empirical Study)

Google Scholar is one of the major academic search engines but its ranking algorithm for academic articles is unknown. In recent studies we partly reverse-engineered the algorithm. This paper presents the results of our third study. While the first study provided a broad overview and the second study focused on researching the impact of citation counts, the current study focused on analyzing the correlation of an article's age and its ranking in Google Scholar. In other words, it was analyzed if older/recent published articles are more/less likely to appear in a top position in Google Scholar's result lists. For our study, age and rankings of 1,099,749 articles retrieved via 2,100 search queries were analyzed. The analysis revealed that an article's age seems to play no significant role in Google Scholar's ranking algorithm. It is also discussed why this might lead to a suboptimal ranking.