“…During such expert validation, the quality of recommendations is inquired by a group of 'experts', which may be the researchers themselves, HR/recruitment experts, or sometimes students (e.g., [85]). Although the choice for expert validation is rarely discussed, we do find that for CBR and KB job recommender systems, approximately half of the contributions use expert validation [63,64,27,65,9,127,128,57,115,88,109,45].…”