As mentioned above, the introduction of a mathematical function to approximate observed data readily allows us to make quick predictions for future publications and/or citations of research topics. To validate the accuracy of the predictions, we fit the polynomial function by using the available bibliographic data for the years 2000 to 2019 and make predictions for publications and citations for years 2020 to 2022 (Figure ). As can be seen from the results the derived mathematical function produces highly accurate predictions with an average R 2 well above 0.9 for the years 2020 and 2021, and only the R 2 of the prediction for publications in 2022 is below 0.9. This gives us high confidence that the derived function approximates very well with the observed data and therefore can be used successfully to evaluate the emergence of research topics.