  Clarivate Analytics announces highly cited researchers (HCRs) every November
to recognise true pioneers in their respective fields over the last decade who
are one in 1,000 according to citation analysis based on the Web of Science
database. However, the scientometric rules underlying HCR selections have
constantly evolved over the years; thus, a comparative study between HCRs'
academic relevance before and after 2018, when the cross field started to be
included in HCR statistics, is essential. This paper evaluated the consistency
of measurements in 2017 and 2018 by analysing HCR distributions by different
regions and Essential Science Indicators (ESI) fields, studied the effects of
introducing the cross-field category to the original 21 ESI fields, and
portrayed the accurate picture of HCR distributions by region and subject
without the influence of measurement biases. The cross field is believed to
exert great impact on regional and field-specific HCR distributions, especially
for research fields with HCR counts larger than 150. It was other countries and
regions except the US and China that grew with the greatest momentum after the
inclusion of cross-field HCRs.
