Can we use altmetrics at the institutional level? A case study analysing the coverage by research areas of four Spanish universities

INTRODUCTION Social media based indicators or altmetrics have been under scrutiny for the last seven years. Their promise as alternative metrics for measuring scholarly impact (Priem, Piwowar, & Hemminger, 2012) is still far from becoming a reality (Torres-Salinas, Cabezas-Clavijo, & Jiménez-Contreras, 2013). Issues with regard to their meaning (Sud & Thelwall, 2014), potential use as alternative or complements to citation indicators (Bornmann, 2014; Costas, Zahedi, & Wouters, 2015a), data collection inconsistencies (Robinson-García, Torres-Salinas, Zahedi, & Costas, 2014) or diversity of sources (Thelwall, Haustein, Larivière, & Sugimoto, 2013) are still under development. In this regard, three lines of work can be observed in regard to altmetric studies: 1) the relation between citations and altmetric indicators (Costas et al., 2015a), 2) their meaning as impact indicators (i.e., Bornmann, 2014; Haustein, Bowman, & Costas, 2015), and, 3) coverage and diversity of social media sources (i.e., Haustein, 2016).