Department of Mathematics2024-11-0920120218-000610.1007/s00026-012-0143-82-s2.0-84865448242https://hdl.handle.net/20.500.14288/2061A defining set of a t-(v, k, lambda) design is a subcollection of its blocks which is contained in a unique t-design with the given parameters. A minimal defining set is a defining set, none of whose proper subcollections is a defining set. The spectrum of minimal defining sets of a design D is the set {|M| | M is a minimal defining set of D}. The unique simple design with parameters is said to be the full design on v elements. This paper studies the minimal defining sets of full designs when t = 2 and k = 3. The largest known minimal defining set is given. The existence of a continuous section of the spectrum comprising asymptotically 9v (2)/50 values is shown. This gives a quadratic length section of continuous spectrum where only a linear section with respect to v was known before.pdfApplied mathematicsJournal Article0219-3094https://doi.org/10.1007/s00026-012-0143-8307762800005Q4NOIR00245