rubin stuart spawar gydugzbnktnnavymil prof hutter make excellent points pursuant chaitins randomization kolmogorov complexity course synonymous one difference however alluded whole science underpinning evolution heuristics perform clustering classification task methods address point thank stuart rubin phd sscsd tel 619 5533554 fax 619 5531130 e gydugzbnktnnavymil original message nhipljlbixengrorstedu mailtonhipljlbixengrorstedu behalf marcus hutter sent saturday december 01 2007 1204 faqengrorstedu cc lotfi zadeh subject uai define similarity dear lofti paul vitanyi others developed universal similarity based kolmogorov complexity k general optimality properties justifies label universal applied wide range problems phylogenetic tree reconstruction similarity languages determining composer pieces music idea two objects b similar better compressed jointly separately difference compression length dabkakbkab used dissimilarity measure know candidate except variants may honestly called universal similarity agree degree similarity depends purpose discussed kolmogorov complexity mailing list years ago httpmailmantieduchpipermailkolmogorov2004q1000112html one show smaller computable distance measure satisfying krafts inequality always right similarity relation right meaning clusters wrt desired property eg minimizing erroneous classifications using might sufficient perform desired classification task although universal mathematical sense imply universally good every clustering classification task hand experimental success universal metric remarkable light considerations even astonishing informationtheoretic dominant feature seems often one interested consideration may also explain variants sometimes fail would great one could augment adapt classification problem hand theoretically elegant way allow grouping wrt desired property best marcus ______________________ marcus hutter assoc prof rsise room b259 building 115 australian national university corner north daley road canberra act 0200 australia phone 6102 612 51605 fax 6102 612 58651 email jdykjnglapjsanueduau httprsiseanueduaumarcus machine learning summer school 2008 httpkioloa08mlsscc fri 08 aug 2008 020307 0800 uai define similarity