{"id":399350,"date":"2017-07-12T02:51:50","date_gmt":"2017-07-12T09:51:50","guid":{"rendered":"https:\/\/www.microsoft.com\/en-us\/research\/?post_type=msr-research-item&#038;p=399350"},"modified":"2018-10-16T20:00:36","modified_gmt":"2018-10-17T03:00:36","slug":"using-asymmetric-distributions-improve-classi%ef%ac%81er-probabilities-comparison-new-standard-parametric-methods","status":"publish","type":"msr-research-item","link":"https:\/\/www.microsoft.com\/en-us\/research\/publication\/using-asymmetric-distributions-improve-classi%ef%ac%81er-probabilities-comparison-new-standard-parametric-methods\/","title":{"rendered":"Using Asymmetric Distributions to Improve Classi\u00ef\u00ac\u0081er Probabilities: A Comparison of New and Standard Parametric Methods"},"content":{"rendered":"<p>For many discriminative classi\ufb01ers, it is desirable to convert an unnormalized con\ufb01dence score output from the classi\ufb01er to a normalized probability estimate. Such a method can also be used for creating better estimates from a probabilistic classi\ufb01er that outputs poor estimates. Typical parametric methods have an underlying assumption that the score distribution for a class is symmetric; we motivate why this assumption is undesirable, especially when the scores are output by a classi\ufb01er. Two asymmetric families, an asymmetric generalization of a Gaussian and a Laplace distribution, are presented, and a method of \ufb01tting them in expected linear time is described. Finally, an experimental analysis of parametric \ufb01ts to the outputs of two text classi\ufb01ers, naive Bayes (which is known to emit poor probabilities) and a linear SVM, is conducted. The analysis shows that one of these asymmetric families is theoretically attractive (introducing few new parameters while increasing \ufb02exibility), computationally ef\ufb01cient, and empirically preferable.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>For many discriminative classi\ufb01ers, it is desirable to convert an unnormalized con\ufb01dence score output from the classi\ufb01er to a normalized probability estimate. Such a method can also be used for creating better estimates from a probabilistic classi\ufb01er that outputs poor estimates. Typical parametric methods have an underlying assumption that the score distribution for a class [&hellip;]<\/p>\n","protected":false},"featured_media":0,"template":"","meta":{"msr-url-field":"","msr-podcast-episode":"","msrModifiedDate":"","msrModifiedDateEnabled":false,"ep_exclude_from_search":false,"_classifai_error":"","msr-author-ordering":null,"msr_publishername":"","msr_publisher_other":"","msr_booktitle":"","msr_chapter":"","msr_edition":"Computer Science Department, School of Computer Science, Carnegie Mellon University (See errata at http:\/\/www.cs.cmu.edu\/~pbennett\/papers\/errata-for-asymmetric.html . Also a revised version of this work appears in SIGIR 2003.)","msr_editors":"","msr_how_published":"","msr_isbn":"","msr_issue":"","msr_journal":"","msr_number":"CMU-CS-02-126","msr_organization":"","msr_pages_string":"","msr_page_range_start":"","msr_page_range_end":"","msr_series":"","msr_volume":"","msr_copyright":"","msr_conference_name":"","msr_doi":"","msr_arxiv_id":"","msr_s2_paper_id":"","msr_mag_id":"","msr_pubmed_id":"","msr_other_authors":"","msr_other_contributors":"","msr_speaker":"","msr_award":"","msr_affiliation":"","msr_institution":"","msr_host":"","msr_version":"","msr_duration":"","msr_original_fields_of_study":"","msr_release_tracker_id":"","msr_s2_match_type":"","msr_citation_count_updated":"","msr_published_date":"2002-04-09","msr_highlight_text":"","msr_notes":"Computer Science Department, School of Computer Science, Carnegie Mellon University (See errata at http:\/\/www.cs.cmu.edu\/~pbennett\/papers\/errata-for-asymmetric.html . Also a revised version of this work appears in SIGIR 2003.)","msr_longbiography":"","msr_publicationurl":"http:\/\/reports-archive.adm.cs.cmu.edu\/anon\/2002\/CMU-CS-02-126-c.pdf","msr_external_url":"","msr_secondary_video_url":"","msr_conference_url":"","msr_journal_url":"","msr_s2_pdf_url":"","msr_year":0,"msr_citation_count":0,"msr_influential_citations":0,"msr_reference_count":0,"msr_s2_match_confidence":0,"msr_microsoftintellectualproperty":true,"msr_s2_open_access":false,"msr_s2_author_ids":[],"msr_pub_ids":[],"msr_hide_image_in_river":0,"footnotes":""},"msr-research-highlight":[],"research-area":[13556,13555],"msr-publication-type":[193718],"msr-publisher":[],"msr-focus-area":[],"msr-locale":[268875],"msr-post-option":[],"msr-field-of-study":[],"msr-conference":[],"msr-journal":[],"msr-impact-theme":[],"msr-pillar":[],"class_list":["post-399350","msr-research-item","type-msr-research-item","status-publish","hentry","msr-research-area-artificial-intelligence","msr-research-area-search-information-retrieval","msr-locale-en_us"],"msr_publishername":"","msr_edition":"Computer Science Department, School of Computer Science, Carnegie Mellon University (See errata at http:\/\/www.cs.cmu.edu\/~pbennett\/papers\/errata-for-asymmetric.html . Also a revised version of this work appears in SIGIR 2003.)","msr_affiliation":"","msr_published_date":"2002-04-09","msr_host":"","msr_duration":"","msr_version":"","msr_speaker":"","msr_other_contributors":"","msr_booktitle":"","msr_pages_string":"","msr_chapter":"","msr_isbn":"","msr_journal":"","msr_volume":"","msr_number":"CMU-CS-02-126","msr_editors":"","msr_series":"","msr_issue":"","msr_organization":"","msr_how_published":"","msr_notes":"Computer Science Department, School of Computer Science, Carnegie Mellon University (See errata at http:\/\/www.cs.cmu.edu\/~pbennett\/papers\/errata-for-asymmetric.html . Also a revised version of this work appears in SIGIR 2003.)","msr_highlight_text":"","msr_release_tracker_id":"","msr_original_fields_of_study":"","msr_download_urls":"","msr_external_url":"","msr_secondary_video_url":"","msr_longbiography":"","msr_microsoftintellectualproperty":1,"msr_main_download":"","msr_publicationurl":"http:\/\/reports-archive.adm.cs.cmu.edu\/anon\/2002\/CMU-CS-02-126-c.pdf","msr_doi":"","msr_publication_uploader":[{"type":"url","title":"http:\/\/reports-archive.adm.cs.cmu.edu\/anon\/2002\/CMU-CS-02-126-c.pdf","viewUrl":false,"id":false,"label_id":0}],"msr_related_uploader":"","msr_citation_count":0,"msr_citation_count_updated":"","msr_s2_paper_id":"","msr_influential_citations":0,"msr_reference_count":0,"msr_arxiv_id":"","msr_s2_author_ids":[],"msr_s2_open_access":false,"msr_s2_pdf_url":null,"msr_attachments":[{"id":0,"url":"http:\/\/reports-archive.adm.cs.cmu.edu\/anon\/2002\/CMU-CS-02-126-c.pdf"}],"msr-author-ordering":[{"type":"edited_text","value":"Paul N. Bennett","user_id":33201,"rest_url":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/microsoft-research\/v1\/researchers?person=Paul N. Bennett"}],"msr_impact_theme":[],"msr_research_lab":[],"msr_event":[],"msr_group":[],"msr_project":[],"publication":[],"video":[],"msr-tool":[],"msr_publication_type":"techreport","related_content":[],"_links":{"self":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-research-item\/399350","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-research-item"}],"about":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/types\/msr-research-item"}],"version-history":[{"count":2,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-research-item\/399350\/revisions"}],"predecessor-version":[{"id":518269,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-research-item\/399350\/revisions\/518269"}],"wp:attachment":[{"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/media?parent=399350"}],"wp:term":[{"taxonomy":"msr-research-highlight","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-research-highlight?post=399350"},{"taxonomy":"msr-research-area","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/research-area?post=399350"},{"taxonomy":"msr-publication-type","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-publication-type?post=399350"},{"taxonomy":"msr-publisher","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-publisher?post=399350"},{"taxonomy":"msr-focus-area","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-focus-area?post=399350"},{"taxonomy":"msr-locale","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-locale?post=399350"},{"taxonomy":"msr-post-option","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-post-option?post=399350"},{"taxonomy":"msr-field-of-study","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-field-of-study?post=399350"},{"taxonomy":"msr-conference","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-conference?post=399350"},{"taxonomy":"msr-journal","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-journal?post=399350"},{"taxonomy":"msr-impact-theme","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-impact-theme?post=399350"},{"taxonomy":"msr-pillar","embeddable":true,"href":"https:\/\/www.microsoft.com\/en-us\/research\/wp-json\/wp\/v2\/msr-pillar?post=399350"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}