We are an independent linguistic Quality Assurance & Quality Control organisation specialising in translation, adaptation, and verification of materials for use in large-scale, multilingual projects. We have core staff of 10 linguists, and a network of over 90 expert verifiers whom we train, coordinate and supervise. All our verifiers are experienced translators and/or teachers; and all have one or several higher-education degrees, mostly in philology, translation, sociology or educational science. They all are trained in verifying data collection instruments and in documenting their interventions in a standardised way following the methodology, procedures and standards that cApStAn developed for this purpose. Proofreading and linguistic expertise forms only part of their skills as verifiers also need to check equivalence - level of difficulty of the items, register, psychometric properties, layout - of the respective national version with the international source version.