BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Samory Kpotufe (Columbia) DTSTART:20200715T140000Z DTEND:20200715T150000Z DTSTAMP:20260423T021139Z UID:MADPlus/12 DESCRIPTION:Title: Some recent insights on transfer-learning\nby Samory Kpotufe (Columbi a) as part of MAD+\n\n\nAbstract\nA common situation in Machine Learning i s one where training data is not fully representative of a target populati on due to bias in the sampling mechanism or high costs in sampling the tar get population\; in such situations\, we aim to ’transfer’ relevant in formation from the training data (a.k.a. source data) to the target applic ation. How much information is in the source data? How much target data sh ould we collect if any? These are all practical questions that depend cruc ially on ‘how far’ the source domain is from the target. However\, how to properly measure ‘distance’ between source and target domains rema ins largely unclear.\n\nIn this talk we will argue that much of the tradit ional notions of ‘distance’ (e.g. KL-divergence\, extensions of TV suc h as D_A discrepancy\, density-ratios\, Wasserstein distance) can yield an over-pessimistic picture of transferability. Instead\, we show that some new notions of ‘relative dimension’ between source and target (which w e simply term ‘transfer-exponents’) capture a continuum from easy to h ard transfer. Transfer-exponents uncover a rich set of situations where tr ansfer is possible even at fast rates\, encode relative benefits of source and target samples\, and have interesting implications for related proble ms such as multi-task or multi-source learning.\n\nIn particular\, in the case of multi-source learning\, we will discuss (if time permits) a strong dichotomy between minimax and adaptive rates: no adaptive procedure can a chieve a rate better than single source rates\, although minimax (oracle) procedures can.\n\nThe talk is based on earlier work with Guillaume Martin et\, and ongoing work with Steve Hanneke.\n LOCATION:https://researchseminars.org/talk/MADPlus/12/ END:VEVENT END:VCALENDAR