A new Slop University paper treats a 110 cm amusement ride-height rule as a regression discontinuity and finds contested measurements falling 38.5 percentage points across the threshold while residual restraint gap moves 0.4 mm.
A study of 9,318 queue presentations at 14 amusement rides finds contested measurements stepping 38 points at 110 centimetres while restraint gap moves 0.4 millimetres
Every child who queued for one of fourteen amusement rides last season was measured twice: once against the board at the gate, and again a minute later on a stadiometer in a bay beside the exit path. The two readings disagreed by an average of 1.6 centimetres.
Contested at 110 Centimetres, deposited today through the Office of Research Outputs, uses that second measurement to ask what the operator’s minimum-height rule actually separates. Across 9,318 presentations falling within 14 centimetres of the line, the probability that a measurement was repeated, escalated or disputed dropped by 38.5 percentage points on crossing it. The residual gap left by the restraint, measured for every child on the static rigs the operator uses for its own annual checks, moved by 0.4 millimetres.
A line drawn at a queue entry is one of the few institutional decisions a family gets to watch being made. We would welcome the questions that raises, including the ones we have not thought to ask about it ourselves.
— Dr Lindiwe Achterberg, Lecturer, School of Emergent Priorities
An archival strand traced the figure to a 1987 manufacturer’s plate for a lap bar now fitted to three of the fourteen rides. The other eleven were re-seated between 2004 and 2019 with restraints specified to lower minimums, and the group ride-safety schedule carried 110 centimetres through each refurbishment. The operator’s monthly safety pack reports refusals per thousand presentations, a rate that rose across the season.
“The School has spent years on priorities that outlast the reasons they were adopted for, and most of them are hard to point at,” said Dr Petra Umbile, Postdoctoral Fellow in the School of Emergent Priorities. “This one is bolted to a post at child height.”
Slop University regards the provenance of a number in daily use as a legitimate object of study, and would like the asking of it to become less remarkable than it currently is. The full paper is available from the University’s research repository under an open licence, doi:10.5555/slop.4nwepl.