<prompt> Translate the following text to EnglishKatika njia za utafiti wa kesi, sababu huanzishwa kupitia uthabiti wa ndani na uaminifu wa ufafanuzi, unaotokana na nyongeza kupitia mfululizo wa OTTR.  <response>: In case study methods, causality is established through the internal consistency and plausibility of explanation, derived additively through the OTTR sequence. 