{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,31]],"date-time":"2026-01-31T10:08:13Z","timestamp":1769854093404,"version":"3.49.0"},"reference-count":5,"publisher":"MIT Press - Journals","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Artificial Life"],"published-print":{"date-parts":[[2005,9]]},"abstract":"<jats:p> We present a novel formal interpretation of dynamical hierarchies based on information theory, in which each level is a near-state-determined system, and levels are related to one another in a partial ordering. This reformulation moves away from previous definitions, which have considered unique hierarchies of structures or objects arranged in aggregates. Instead, we consider hierarchies of dynamical systems: these are more suited to describing living systems, which are not mere aggregates, but organizations. Transformations from lower to higher levels in a hierarchy are redescriptions that lose information. There are two criteria for partial ordering. One is a state-dependence criterion enforcing predictability within a level. The second is a distinctness criterion enforcing the idea that the higher-level description must do more than just throw information away. We hope this will be a useful tool for empirical studies of both computational and physical dynamical hierarchies. <\/jats:p>","DOI":"10.1162\/106454605774270615","type":"journal-article","created":{"date-parts":[[2005,9,21]],"date-time":"2005-09-21T21:07:38Z","timestamp":1127336858000},"page":"459-472","source":"Crossref","is-referenced-by-count":11,"title":["Levels of Description: A Novel Approach to Dynamical Hierarchies"],"prefix":"10.1162","volume":"11","author":[{"given":"Simon","family":"McGregor","sequence":"first","affiliation":[{"name":"Centre for Research in Cognitive Science (COGS), University of Sussex, BN1 9QH UK"}]},{"given":"Chrisantha","family":"Fernando","sequence":"additional","affiliation":[{"name":"Centre for Research in Cognitive Science (COGS), University of Sussex, BN1 9QH UK"}]}],"member":"281","reference":[{"key":"p_4","doi-asserted-by":"publisher","DOI":"10.1038\/scientificamerican1070-120"},{"key":"p_5","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.96.21.11904"},{"key":"p_6","doi-asserted-by":"publisher","DOI":"10.1162\/106454601317296997"},{"key":"p_11","doi-asserted-by":"publisher","DOI":"10.1162\/106454601317296988"},{"key":"p_12","doi-asserted-by":"publisher","DOI":"10.1162\/106454601317297004"}],"container-title":["Artificial Life"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mitpressjournals.org\/doi\/pdf\/10.1162\/106454605774270615","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,3,12]],"date-time":"2021-03-12T21:32:06Z","timestamp":1615584726000},"score":1,"resource":{"primary":{"URL":"https:\/\/direct.mit.edu\/artl\/article\/11\/4\/459-472\/2502"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2005,9]]},"references-count":5,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2005,9]]}},"alternative-id":["10.1162\/106454605774270615"],"URL":"https:\/\/doi.org\/10.1162\/106454605774270615","relation":{},"ISSN":["1064-5462","1530-9185"],"issn-type":[{"value":"1064-5462","type":"print"},{"value":"1530-9185","type":"electronic"}],"subject":[],"published":{"date-parts":[[2005,9]]}}}