{"id":"https://openalex.org/W2101456123","doi":"https://doi.org/10.1162/evco_a_00123","title":"Constrained Novelty Search: A Study on Game Content Generation","display_name":"Constrained Novelty Search: A Study on Game Content Generation","publication_year":2014,"publication_date":"2014-03-07","ids":{"openalex":"https://openalex.org/W2101456123","doi":"https://doi.org/10.1162/evco_a_00123","mag":"2101456123","pmid":"https://pubmed.ncbi.nlm.nih.gov/24605847"},"language":"en","primary_location":{"id":"doi:10.1162/evco_a_00123","is_oa":false,"landing_page_url":"https://doi.org/10.1162/evco_a_00123","pdf_url":null,"source":{"id":"https://openalex.org/S38677346","display_name":"Evolutionary Computation","issn_l":"1063-6560","issn":["1063-6560","1530-9304"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310315718","host_organization_name":"The MIT Press","host_organization_lineage":["https://openalex.org/P4310315718"],"host_organization_lineage_names":["The MIT Press"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Evolutionary Computation","raw_type":"journal-article"},"type":"article","indexed_in":["crossref","pubmed"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"https://www.um.edu.mt/library/oar//handle/123456789/22893","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5012075090","display_name":"Antonios Liapis","orcid":"https://orcid.org/0000-0001-5554-1961"},"institutions":[{"id":"https://openalex.org/I83467386","display_name":"IT University of Copenhagen","ror":"https://ror.org/02309jg23","country_code":"DK","type":"education","lineage":["https://openalex.org/I83467386"]}],"countries":["DK"],"is_corresponding":false,"raw_author_name":"Antonios Liapis","raw_affiliation_strings":["Center for Computer Games Research, IT University of Copenhagen, Copenhagen, 2300, Denmark"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Center for Computer Games Research, IT University of Copenhagen, Copenhagen, 2300, Denmark","institution_ids":["https://openalex.org/I83467386"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5072029181","display_name":"Georgios N. Yannakakis","orcid":"https://orcid.org/0000-0001-7793-1450"},"institutions":[{"id":"https://openalex.org/I197854408","display_name":"University of Malta","ror":"https://ror.org/03a62bv60","country_code":"MT","type":"education","lineage":["https://openalex.org/I197854408"]}],"countries":["MT"],"is_corresponding":false,"raw_author_name":"Georgios N. Yannakakis","raw_affiliation_strings":["Institute of Digital Games, University of Malta, Msida, 2080, Malta"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Institute of Digital Games, University of Malta, Msida, 2080, Malta","institution_ids":["https://openalex.org/I197854408"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5077267552","display_name":"Julian Togelius","orcid":"https://orcid.org/0000-0003-3128-4598"},"institutions":[{"id":"https://openalex.org/I83467386","display_name":"IT University of Copenhagen","ror":"https://ror.org/02309jg23","country_code":"DK","type":"education","lineage":["https://openalex.org/I83467386"]}],"countries":["DK"],"is_corresponding":false,"raw_author_name":"Julian Togelius","raw_affiliation_strings":["Center for Computer Games Research, IT University of Copenhagen, Copenhagen, 2300, Denmark"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Center for Computer Games Research, IT University of Copenhagen, Copenhagen, 2300, Denmark","institution_ids":["https://openalex.org/I83467386"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":2,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":7.4553,"has_fulltext":false,"cited_by_count":63,"citation_normalized_percentile":{"value":0.97213877,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":89,"max":99},"biblio":{"volume":"23","issue":"1","first_page":"101","last_page":"129"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11574","display_name":"Artificial Intelligence in Games","score":0.9998000264167786,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T11574","display_name":"Artificial Intelligence in Games","score":0.9998000264167786,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11197","display_name":"Digital Games and Media","score":0.9932000041007996,"subfield":{"id":"https://openalex.org/subfields/3312","display_name":"Sociology and Political Science"},"field":{"id":"https://openalex.org/fields/33","display_name":"Social Sciences"},"domain":{"id":"https://openalex.org/domains/2","display_name":"Social Sciences"}},{"id":"https://openalex.org/T11975","display_name":"Evolutionary Algorithms and Applications","score":0.9922000169754028,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/novelty","display_name":"Novelty","score":0.9111634492874146},{"id":"https://openalex.org/keywords/population","display_name":"Population","score":0.5746253132820129},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.5607464909553528},{"id":"https://openalex.org/keywords/boosting","display_name":"Boosting (machine learning)","score":0.5465412735939026},{"id":"https://openalex.org/keywords/search-algorithm","display_name":"Search algorithm","score":0.527967095375061},{"id":"https://openalex.org/keywords/beam-search","display_name":"Beam search","score":0.492031067609787},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.47165122628211975},{"id":"https://openalex.org/keywords/mathematical-optimization","display_name":"Mathematical optimization","score":0.4508213996887207},{"id":"https://openalex.org/keywords/selection","display_name":"Selection (genetic algorithm)","score":0.43039470911026},{"id":"https://openalex.org/keywords/space","display_name":"Space (punctuation)","score":0.425723671913147},{"id":"https://openalex.org/keywords/machine-learning","display_name":"Machine learning","score":0.34564369916915894},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.32636791467666626},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.2170698046684265}],"concepts":[{"id":"https://openalex.org/C2778738651","wikidata":"https://www.wikidata.org/wiki/Q16546687","display_name":"Novelty","level":2,"score":0.9111634492874146},{"id":"https://openalex.org/C2908647359","wikidata":"https://www.wikidata.org/wiki/Q2625603","display_name":"Population","level":2,"score":0.5746253132820129},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.5607464909553528},{"id":"https://openalex.org/C46686674","wikidata":"https://www.wikidata.org/wiki/Q466303","display_name":"Boosting (machine learning)","level":2,"score":0.5465412735939026},{"id":"https://openalex.org/C125583679","wikidata":"https://www.wikidata.org/wiki/Q755673","display_name":"Search algorithm","level":2,"score":0.527967095375061},{"id":"https://openalex.org/C19889080","wikidata":"https://www.wikidata.org/wiki/Q2835852","display_name":"Beam search","level":3,"score":0.492031067609787},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.47165122628211975},{"id":"https://openalex.org/C126255220","wikidata":"https://www.wikidata.org/wiki/Q141495","display_name":"Mathematical optimization","level":1,"score":0.4508213996887207},{"id":"https://openalex.org/C81917197","wikidata":"https://www.wikidata.org/wiki/Q628760","display_name":"Selection (genetic algorithm)","level":2,"score":0.43039470911026},{"id":"https://openalex.org/C2778572836","wikidata":"https://www.wikidata.org/wiki/Q380933","display_name":"Space (punctuation)","level":2,"score":0.425723671913147},{"id":"https://openalex.org/C119857082","wikidata":"https://www.wikidata.org/wiki/Q2539","display_name":"Machine learning","level":1,"score":0.34564369916915894},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.32636791467666626},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.2170698046684265},{"id":"https://openalex.org/C144024400","wikidata":"https://www.wikidata.org/wiki/Q21201","display_name":"Sociology","level":0,"score":0.0},{"id":"https://openalex.org/C27206212","wikidata":"https://www.wikidata.org/wiki/Q34178","display_name":"Theology","level":1,"score":0.0},{"id":"https://openalex.org/C138885662","wikidata":"https://www.wikidata.org/wiki/Q5891","display_name":"Philosophy","level":0,"score":0.0},{"id":"https://openalex.org/C149923435","wikidata":"https://www.wikidata.org/wiki/Q37732","display_name":"Demography","level":1,"score":0.0},{"id":"https://openalex.org/C111919701","wikidata":"https://www.wikidata.org/wiki/Q9135","display_name":"Operating system","level":1,"score":0.0}],"mesh":[{"descriptor_ui":"D000465","descriptor_name":"Algorithms","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D000465","descriptor_name":"Algorithms","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D000465","descriptor_name":"Algorithms","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D003198","descriptor_name":"Computer Simulation","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D003198","descriptor_name":"Computer Simulation","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D003198","descriptor_name":"Computer Simulation","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D008962","descriptor_name":"Models, Theoretical","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D008962","descriptor_name":"Models, Theoretical","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D008962","descriptor_name":"Models, Theoretical","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D018910","descriptor_name":"Video Games","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D018910","descriptor_name":"Video Games","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D018910","descriptor_name":"Video Games","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D057386","descriptor_name":"Search Engine","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D057386","descriptor_name":"Search Engine","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D057386","descriptor_name":"Search Engine","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false}],"locations_count":3,"locations":[{"id":"doi:10.1162/evco_a_00123","is_oa":false,"landing_page_url":"https://doi.org/10.1162/evco_a_00123","pdf_url":null,"source":{"id":"https://openalex.org/S38677346","display_name":"Evolutionary Computation","issn_l":"1063-6560","issn":["1063-6560","1530-9304"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310315718","host_organization_name":"The MIT Press","host_organization_lineage":["https://openalex.org/P4310315718"],"host_organization_lineage_names":["The MIT Press"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Evolutionary Computation","raw_type":"journal-article"},{"id":"pmid:24605847","is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/24605847","pdf_url":null,"source":{"id":"https://openalex.org/S4306525036","display_name":"PubMed","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Evolutionary computation","raw_type":null},{"id":"pmh:oai:www.um.edu.mt:123456789/22893","is_oa":true,"landing_page_url":"https://www.um.edu.mt/library/oar//handle/123456789/22893","pdf_url":null,"source":{"id":"https://openalex.org/S4306400782","display_name":"OAR@UM (University of Malta)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I197854408","host_organization_name":"University of Malta","host_organization_lineage":["https://openalex.org/I197854408"],"host_organization_lineage_names":[],"type":"repository"},"license":"other-oa","license_id":"https://openalex.org/licenses/other-oa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"","raw_type":"info:eu-repo/semantics/article"}],"best_oa_location":{"id":"pmh:oai:www.um.edu.mt:123456789/22893","is_oa":true,"landing_page_url":"https://www.um.edu.mt/library/oar//handle/123456789/22893","pdf_url":null,"source":{"id":"https://openalex.org/S4306400782","display_name":"OAR@UM (University of Malta)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I197854408","host_organization_name":"University of Malta","host_organization_lineage":["https://openalex.org/I197854408"],"host_organization_lineage_names":[],"type":"repository"},"license":"other-oa","license_id":"https://openalex.org/licenses/other-oa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"","raw_type":"info:eu-repo/semantics/article"},"sustainable_development_goals":[{"id":"https://metadata.un.org/sdg/4","display_name":"Quality Education","score":0.41999998688697815}],"awards":[],"funders":[{"id":"https://openalex.org/F4320338370","display_name":"FP7 Information and Communication Technologies","ror":null}],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":41,"referenced_works":["https://openalex.org/W38161365","https://openalex.org/W51299923","https://openalex.org/W116651512","https://openalex.org/W124424457","https://openalex.org/W776164697","https://openalex.org/W1502579426","https://openalex.org/W1605771973","https://openalex.org/W1977418904","https://openalex.org/W1997107172","https://openalex.org/W2001466640","https://openalex.org/W2037246492","https://openalex.org/W2039910796","https://openalex.org/W2041224215","https://openalex.org/W2060522639","https://openalex.org/W2061554433","https://openalex.org/W2080422307","https://openalex.org/W2092735940","https://openalex.org/W2102015193","https://openalex.org/W2102669142","https://openalex.org/W2113410615","https://openalex.org/W2119814172","https://openalex.org/W2121975403","https://openalex.org/W2144343387","https://openalex.org/W2150333870","https://openalex.org/W2151083897","https://openalex.org/W2154022540","https://openalex.org/W2157166695","https://openalex.org/W2160237541","https://openalex.org/W2167340571","https://openalex.org/W2168115594","https://openalex.org/W2172117040","https://openalex.org/W2172224046","https://openalex.org/W2172259501","https://openalex.org/W2190479596","https://openalex.org/W2200701583","https://openalex.org/W2224682476","https://openalex.org/W2340334052","https://openalex.org/W2395774634","https://openalex.org/W2579414847","https://openalex.org/W3000528734","https://openalex.org/W4255297287"],"related_works":["https://openalex.org/W4386269615","https://openalex.org/W4390091683","https://openalex.org/W1994919150","https://openalex.org/W58921990","https://openalex.org/W2204575588","https://openalex.org/W2081821176","https://openalex.org/W3084994579","https://openalex.org/W3106196307","https://openalex.org/W4320350517","https://openalex.org/W2998661990"],"abstract_inverted_index":{"Novelty":[0],"search":[1,9,22,36,49,54,57,131,168],"is":[2,113,161,182],"a":[3,21],"recent":[4],"algorithm":[5,160],"geared":[6],"toward":[7],"exploring":[8],"spaces":[10],"without":[11],"regard":[12],"to":[13,102,184],"objectives.":[14],"When":[15],"the":[16,44,60,63,68,103,116,127,158,164,167,171,176],"presence":[17],"of":[18,46,105,115,119,143,150,166,179,190],"constraints":[19],"divides":[20],"space":[23,26,169],"into":[24],"feasible":[25,61,82,144],"and":[27,50,62,75,83,139,170],"infeasible":[28,64,86],"space,":[29],"interesting":[30],"implications":[31],"arise":[32],"regarding":[33],"how":[34],"novelty":[35,48,53,130,151,192],"explores":[37],"such":[38],"spaces.":[39],"This":[40],"paper":[41],"elaborates":[42],"on":[43,163],"problem":[45,104,118],"constrained":[47,129,154],"proposes":[51],"two":[52,77],"algorithms":[55,73,99],"which":[56,112],"within":[58],"both":[59,72],"space.":[65],"Inspired":[66],"by":[67],"FI-2pop":[69],"genetic":[70,172],"algorithm,":[71],"maintain":[74],"evolve":[76],"separate":[78],"populations,":[79],"one":[80,84],"with":[81,85],"individuals,":[87],"while":[88],"each":[89],"population":[90],"can":[91,133],"use":[92],"its":[93],"own":[94],"selection":[95],"method.":[96],"The":[97],"proposed":[98,177],"are":[100],"applied":[101],"generating":[106],"diverse":[107,141],"but":[108],"playable":[109],"game":[110,121,145],"levels,":[111],"representative":[114],"larger":[117,138],"procedural":[120],"content":[122],"generation.":[123],"Results":[124],"show":[125],"that":[126],"two-population":[128,191],"methods":[132,149],"create,":[134],"under":[135],"certain":[136],"conditions,":[137],"more":[140],"sets":[142],"levels":[146],"than":[147],"current":[148],"search,":[152],"whether":[153],"or":[155],"unconstrained.":[156],"However,":[157],"best":[159],"contingent":[162],"particularities":[165],"operators":[173],"used.":[174],"Additionally,":[175],"enhancement":[178],"offspring":[180],"boosting":[181],"shown":[183],"enhance":[185],"performance":[186],"in":[187],"all":[188],"cases":[189],"search.":[193]},"counts_by_year":[{"year":2026,"cited_by_count":1},{"year":2025,"cited_by_count":4},{"year":2024,"cited_by_count":2},{"year":2023,"cited_by_count":3},{"year":2022,"cited_by_count":9},{"year":2021,"cited_by_count":6},{"year":2020,"cited_by_count":9},{"year":2019,"cited_by_count":5},{"year":2018,"cited_by_count":6},{"year":2017,"cited_by_count":6},{"year":2016,"cited_by_count":9},{"year":2015,"cited_by_count":2},{"year":2014,"cited_by_count":1}],"updated_date":"2026-05-21T06:26:12.895304","created_date":"2025-10-10T00:00:00"}