A School of Continuous Improvement poster reports a taxonomy of kitchen compost caddies that the collection roster now treats as the instruction for bin night.
A four-kind stewardship taxonomy grades the bench caddy, and crews skip any kitchen below Tipped-nightly.
The Bench-Caddy Stewardship Taxonomy now sits on the collection roster. A new research poster from the School of Continuous Improvement reports how a four-kind classification of kitchen compost caddies became the instruction kerbside crews follow on bin night.
Unannounced visits to ninety-six kitchens, sampled fortnightly over fourteen months, assigned each household one of four pre-registered kinds: Tipped-nightly, Overnight-open, Forgotten-under, or Ceremonial-empty. The published grade went to the roster the morning of each collection. None of the kinds were adjusted after the first visit, and crews had no override.
A caddy that has a kind is a caddy a roster can act on. We wanted to know whether the kinds would hold still long enough to be used that way.
— Dr Thandiwe Solberg, Senior Lecturer and Convenor, Demo Quarter
Once the eligibility floor stepped to Tipped-nightly, crews skipped 31 per cent of addresses on the next bin night, and the skip rate held through the following three quarters. The School has since adopted that floor as the standing condition for green-lid collection, with no crew-level override and no exception sustained for more than a single review cycle.
Dr Joost Nwosu, Postdoctoral Fellow in the School of Continuous Improvement, said the interesting movement was not the skip rate itself. “Once the floor is in the roster, the question is what households do with the empty caddy the night before the visit,” he said, working on the study with Lecturer Solveig Adeyemi.
Colleagues describe the poster as classification work of a kind the institution is prepared to live with. The full poster is available from the University’s research repository under an open licence, doi:10.5555/slop.kv6mk5.