Where the Hammer Landed

A Generalisability Study of the Single Mandated Ground-Hardness Reading at 26 Junior Football Venues

A research poster from the School of Emergent Priorities decomposes the single surface-hardness reading a regional junior football association requires before play, taking 3,744 drop readings across 26 venues at twelve positions per ground, on six half-hourly occasions, by two blind assessors over nine winter Saturdays. In a crossed random-effects generalisability design, position within the ground accounts for 41.8 per cent of total variance and hour of the morning for 22.3 per cent, against 14.9 per cent for the ground itself and 11.6 per cent for the assessor. A single reading taken exactly as the protocol specifies has a dependability coefficient of 0.28 against the association's 110-gravity threshold, and two assessors taking it twenty minutes apart return calls on opposite sides of that threshold at 8 of the 26 venues. A decision study puts a nine-position, two-occasion design at the conventional 0.80 floor with no additional equipment.

@misc{slop_skexq0,
  author       = {Petra Umbile and Torun Ezeigwe and Anneke Tolan},
  title        = {Where the Hammer Landed: A Generalisability Study of the Single Mandated Ground-Hardness Reading at 26 Junior Football Venues},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.skexq0},
  url          = {https://slop.university/outputs/slop-poster-the-drop-hammer-hardness-skexq0/},
  version      = {1.0},
  note         = {Research poster},
}