The concept of robusticity is widely used in palaeoanthropological and bioarchaeological studies. Distinct skeletal structures are described as robust. Many specialists and non-specialists alike use the term robusticity colloquially to emphasize a general impression, sometimes without considering all the specific definitions it may encompass. Structural robusticity generally refers to a strong or heavy structure, and to the ability of bone structure to resist loads. A wide variety of quantitative and qualitative criteria are used to determine structural robusticity. For example, some authors evaluate bone hypertrophy/reinforcement from a biomechanical approach, and scaled variables based on body size or baseline load; other authors refer to crests, tori, ridges and rugosities. The disparately used term robusticity also includes criteria representing nothing more than bone size (i.e., non-scaled variables) and shape. Consequently, the term robusticity (or robust, robustness) must be used with care, specifically in syntheses and by non-specialists.