This study is dedicated to the historicization of the criticism of special education at separate special schools that has been voiced in the context of school inclusion. Interdisciplinarily situated in the research field of historical childhood and (primary) school research as well as pedagogical- psychological diagnostics, it examines the consistency - and from this the reliability - of schooling decisions made in the Special Needs Assessment Procedure (SNAP) in the Federal Republic of Germany (FRG) in the 1950s to the 1970s. The basis for this is formed by professional reports written about primary school children examined in the SNAP, which are analyzed using the historical-contextualizing content analysis combined with a qualitative form of typification (cf. Gerhardt 1986; Vogt 2015). In orientation towards Link (1997) and Treptow (2009), occurring decision inconsistencies are project-specifically understood as a 'border zone' between primary school eligibility and the need for special education. As central findings, interpreted from a social constructivist perspective (cf. Berger & Luckmann 2004), the study reveals the existence of a 'border zone' in the FRG during the period under investigation, but only manifesting itself in individual exceptional cases with inconsistent schooling decisions. For the most part, however, the study shows consistent and correspondingly reliable schooling decisions, which are based on a historically traditional selection practice that has been criticized since the 1960s (cf. Kottmann 2006; Garz 2022).weiterlesen