Improving User Profiles for E-Commerce by Genetic algorithms* Yi-Shin Chen and Cyrus Shahab Integrated Media Systems Center and Computer Science Department University of Southern California, Los Angeles, CA 90089-2564 Abstract. Recommendation systems are widely adopted in e-commerce businesses for helping customers locate products they would like to purchase. The major chal- enge for these systems is bridging the gap between the physical characteristics of data with the users'perceptions. In order to address this challenge, employing user profiles to improve accuracy becomes essential. However, the system performance offer learning mechanisms to correct erroneous user in puts In this paper, we extend an existing recommendation system, Yoda, to improve the profiles au tomatically by utilizing users'relevance feedback with genetic algorithms(GA). Our experimental results indicate that the retrieval accuracy is significantly increased by using the G Keywords: e-commerce, recommendation systems, fuzzy logic, soft query clustering, genetic algorithm, relevance feedback 1 Introduct As the amount of available products in e-commerce businesses is burgeon ng, searching for desired products among enormous offerings is becoming increasingly difficult. As a result, e-commerce users frequently suffer from in formation overload. To alleviate this problem, recommendation systems are being widely adopted to help customers locate products they would like to purchase. In essence, these systems apply data analysis techniques to provide a list of recommended products for each online customer. The most famous example in e-commerce businesses is the"Customers who bought feature used in Amazon. comM, which is basically applied to every product page on its websites. With the help of this feature, Amazon. com s system recom mends similar products to the current buyer based on the purchase histories of previous customers who bought the same product This research has been funded in part by NSF grants EEC-9529152(IMSC ERC) nd itR-0082826. NIH-NLM RO1-LM07061, DARPA and USAF hent nr. F30602-99-1-0524, and unrestricted cash/equipment gifts from NCR, M. Intel and suN.￾✂✁☎✄✝✆✟✞✡✠☞☛✍✌✝✎✑✏✓✒✕✔✖✆✘✗✙✆✟✞✛✚✢✜✣✔✖✒✥✤✦✞✧✆✩★✫✪✂✬✭✞✮✁☎✁✯✔✖✆✟✰✱✔✳✲✵✴ ✶✔✡✌✝✔✸✷✟☛✣✰✺✹✻✜✣✎✧✞✧✆✼☛✽✷✟✾✿✁✯✒❁❀ ❂❄❃ ❅❇❆❉❈❊❃❋✢●❍❈❊■✍❋✿❏✦❋▲❑✿●❍▼❉◆P❖▲◗✖❆❉❈▲❏✦❈▲❏✦❘❊❃ ❙❯❚❲❱❇❳✽❨✍❩❭❬✣❱❇❳❫❪✵❴✮❳❫❪❛❵ ❬✛❜❲❝❛❞❡❱❇❳✽❢❣❞✼❤✕❳✽❚❲❱❇❳P❩✐❬✍❚❉❪✵❤✕❥❦❢❣❧♥♠❛❱❇❳P❩✐❜✦♦✽❵ ❳✽❚♥♦✽❳✱♣✸❳✽❧❉❬✣❩q❱❇❢❣❳✽❚❲❱ r✐❚♥❵st❳P❩❇❞q❵ ❱❯❝✧❥✍✉✈❜✦❥❦♠❛❱❇✇♥❳P❩❇❚①❤②❬✍③ ❵✉④❥✍❩❇❚♥❵ ❬✦⑤▲⑥▲❥❦❞❍⑦❍❚♥❨❦❳✽③ ❳✽❞✽⑤⑧❤②⑦⑩⑨❦❶❦❶❦❷❦⑨✣❸❡❹❦❺✍❻✍❼ ❽❁❸❾❢✛❬✍❵ ③➀❿ ➁ ➂❫➃♥➄❛➃♥➄✦➅P➆q➇❇➈✦➆❯➂❫➃♥➆➊➉❊➋❭➌④➍✐➎❊➂✽➋✍➏ ➐❫➑❲➎ ➒✛➓❁➔✽→✽➣✣↔❉↕❦→❦➙❄➛❳✽♦✽❥❦❢❣❢❣❳✽❚❉❪♥❬✣❱❇❵❥❦❚✖❞❡❝❛❞❡❱❇❳✽❢❣❞❁❬✣❩❇❳✕➜✼❵❪❛❳✽③❝❄❬❦❪❛❥❦❧❛❱❇❳❫❪✖❵❚❄❳P❸❾♦✽❥❦❢❣❢❣❳P❩❇♦✽❳✈➝♥♠♥❞q❵❚♥❳✽❞q❞q❳✽❞ ✉④❥✍❩②✇♥❳✽③❧♥❵❚♥❨✖♦✽♠♥❞❡❱❇❥❦❢❣❳P❩❇❞✈③❥❲♦❫❬✣❱❇❳✐❧❛❩❇❥✦❪❛♠♥♦P❱❇❞✈❱❇✇♥❳P❝✡➜②❥❦♠♥③❪❣③ ❵➞t❳✼❱❇❥✱❧♥♠❛❩❇♦❭✇❉❬✍❞q❳❦➟✦➠②✇♥❳❍❢✛❬❫➡❡❥✍❩②♦❭✇❉❬✍③ ❸ ③ ❳✽❚♥❨❦❳✖✉④❥✍❩✸❱❇✇♥❳✽❞q❳✖❞❡❝❛❞❡❱❇❳✽❢❣❞❍❵ ❞✐➝❛❩❇❵❪❛❨❦❵❚♥❨❣❱❇✇♥❳✖❨t❬✍❧➢➝⑧❳P❱❯➜②❳✽❳✽❚①❱❇✇♥❳✖❧♥✇❲❝❛❞q❵ ♦❫❬✍③➤♦❭✇❉❬✣❩❭❬✍♦P❱❇❳P❩❇❵ ❞❡❱❇❵ ♦✽❞✸❥✍✉ ❪♥❬✣❱❭❬✸➜✼❵❱❇✇❣❱❇✇♥❳❍♠♥❞q❳P❩❇❞✽➥✦❧⑧❳P❩❇♦✽❳✽❧❛❱❇❵❥❦❚♥❞✽➟❲❙❯❚✛❥✍❩❭❪❛❳P❩✕❱❇❥✡❬❦❪♥❪✦❩❇❳✽❞q❞✈❱❇✇♥❵ ❞✕♦❭✇❉❬✍③ ③ ❳✽❚♥❨❦❳❦⑤✦❳✽❢❣❧♥③❥❫❝❛❵❚♥❨✖♠♥❞q❳P❩ ❧❛❩❇❥✍➦❉③ ❳✽❞✐❱❇❥✮❵❢❣❧❛❩❇❥✣st❳✡❬✍♦✽♦✽♠❛❩❭❬✍♦P❝➧➝⑧❳✽♦✽❥❦❢❣❳✽❞✐❳✽❞q❞q❳✽❚❲❱❇❵ ❬✍③➀➟➩➨✐❥❫➜②❳✽st❳P❩❫⑤⑧❱❇✇♥❳❄❞❡❝❛❞❡❱❇❳✽❢➫❧⑧❳P❩q✉④❥✍❩❇❢✛❬✍❚♥♦✽❳ ❢✛❬✽❝✱❪❛❳✽❨✍❩❭❬❦❪❛❳✕❪❛♠♥❳✂❱❇❥✼❵❚❉❬✍♦✽♦✽♠❛❩❭❬✍♦P❝✱❥✍✉♥♠♥❞q❳P❩➤❧❛❩❇❥✍➦❉③ ❳✽❞✽➟✍➠②✇♥❳P❩❇❳P✉④❥✍❩❇❳❦⑤❦❬✍❚✖❳P➭❊❳✽♦P❱❇❵st❳✈❞❡❝❛❞❡❱❇❳✽❢➯❞q✇♥❥❦♠♥③❪ ❥✍➭❊❳P❩✈③ ❳❫❬✣❩❇❚♥❵❚♥❨✸❢❣❳✽♦❭✇❉❬✍❚♥❵ ❞q❢❣❞➩❱❇❥✐♦✽❥✍❩q❩❇❳✽♦P❱✈❳P❩q❩❇❥❦❚♥❳✽❥❦♠♥❞✂♠♥❞q❳P❩✈❵❚♥❧♥♠❛❱❇❞✽➟✍❙❯❚✖❱❇✇♥❵ ❞✂❧❉❬✍❧⑧❳P❩❫⑤✣➜②❳✟❳P➲✦❱❇❳✽❚❉❪ ❬✍❚❄❳P➲❛❵ ❞❡❱❇❵❚♥❨✐❩❇❳✽♦✽❥❦❢❣❢❣❳✽❚❉❪♥❬✣❱❇❵❥❦❚❄❞❡❝❛❞❡❱❇❳✽❢✵⑤❫➳✕❥✦❪♥❬✦⑤✍❱❇❥✸❵❢❣❧❛❩❇❥✣st❳✈❱❇✇♥❳②❧❛❩❇❥✍➦❉③ ❳✽❞✈❬✍♠❛❱❇❥❦❢✛❬✣❱❇❵ ♦❫❬✍③ ③❝❄➝❲❝ ♠❛❱❇❵ ③ ❵ ➵✽❵❚♥❨✡♠♥❞q❳P❩❇❞✽➥t❩❇❳✽③ ❳✽s❦❬✍❚♥♦✽❳❍✉④❳✽❳❫❪❛➝❉❬✍♦❭➞✡➜✼❵❱❇✇✧❨❦❳✽❚♥❳P❱❇❵ ♦✐❬✍③❨❦❥✍❩❇❵❱❇✇♥❢❣❞✸➸❾➺✸⑦✸➻❭➟✦➼✐♠❛❩②❳P➲❛❧⑧❳P❩❇❵❢❣❳✽❚❲❱❭❬✍③ ❩❇❳✽❞q♠♥③❱❇❞✡❵❚❉❪❛❵ ♦❫❬✣❱❇❳➽❱❇✇❉❬✣❱✖❱❇✇♥❳➽❩❇❳P❱q❩❇❵ ❳✽s❦❬✍③✕❬✍♦✽♦✽♠❛❩❭❬✍♦P❝✝❵ ❞✖❞q❵❨❦❚♥❵➦❉♦❫❬✍❚❲❱❇③❝✝❵❚♥♦P❩❇❳❫❬✍❞q❳❫❪✝➝❲❝➧♠♥❞q❵❚♥❨✮❱❇✇♥❳ ➺✸⑦✼❸❾➝❉❬✍❞q❳❫❪✧③ ❳❫❬✣❩❇❚♥❵❚♥❨❣❢❣❳✽♦❭✇❉❬✍❚♥❵ ❞q❢✵➟ ➾✿➚♥➪❁➶✧➹▲➘❲➴✕➷❛➬❲■✣❅q➮✣➱❛✃✵✃✵■✍◆✽➮✣■❛❐❫◆P■❦➮✣➱❛✃✵✃✵■✍❋▲❑❊❏❲❒P❃➱❛❋➽◗❭▼⑧◗❇❒P■✍✃①◗✍❐❫❮➊❖❊❰✍❰✍▼✡Ï➱❛Ð❛❃④➮✦❐✍◗❭➱✦❮➀❒✈Ñ♥❖❊■✍◆P▼❛❐ ➮✣Ï❖▲◗❇❒P■✍◆P❃❋❊Ð▲❐⑧Ð❛■✍❋❊■✣❒P❃④➮➽❏✦ÏÐ❛➱❛◆P❃❒P❈❊✃✝❐⑧◆P■✍Ï■✍Ò❲❏✦❋▲➮✣■❄❮➊■✍■❦❑⑧❘▲❏❛➮✽Ó Ô Õ♥Ö❍×⑧Ø❊Ù✱Ú✡Û✡Ü➩×❊Ý❇Ù❍Ö Þ◗✛❒P❈❊■☞❏✦✃✵➱❛❖❊❋♥❒✧➱✦❮✡❏tÒ❲❏✦❃ Ï④❏✦❘❊Ï■①ß❊◆P➱⑧❑⑧❖▲➮❫❒✽◗✧❃❋à■✣❅q➮✣➱❛✃✵✃✵■✍◆✽➮✣■➢❘❊❖▲◗❭❃❋❊■❦◗P◗❭■❦◗✛❃④◗✛❘❊❖❊◆PÐ❛■✍➱❛❋⑧❅ ❃❋❊Ð▲❐✼◗❭■❦❏✦◆✽➮✽❈❊❃❋❊Ð✢❮➊➱❛◆①❑⑧■❦◗❭❃ ◆P■❦❑➯ß❊◆P➱⑧❑⑧❖▲➮❫❒✽◗①❏✦✃✵➱❛❋❊Ðá■✍❋❊➱❛◆P✃✵➱❛❖▲◗✮➱✦â➤■✍◆P❃❋❊Ð♥◗✮❃④◗✵❘➩■❦➮✣➱❛✃✵❃❋❊Ð ❃❋▲➮✣◆P■❦❏❛◗❭❃❋❊Ð❛Ï▼✧❑⑧❃ã➢➮✣❖❊Ï❒❦ä Þ◗✐❏➽◆P■❦◗❭❖❊Ï❒❦❐❛■✣❅q➮✣➱❛✃✵✃✵■✍◆✽➮✣■✱❖▲◗❭■✍◆✽◗②❮➊◆P■❦Ñ♥❖❊■✍❋♥❒PÏ▼✮◗❭❖⑧â➤■✍◆✼❮➊◆P➱❛✃➫❃❋⑧❅ ❮➊➱❛◆P✃①❏❲❒P❃➱❛❋å➱❲Ò❛■✍◆PÏ➱♥❏❛❑❁ä▲æ✈➱☞❏✦Ï Ï■✍Ò❉❃④❏❲❒P■✛❒P❈❊❃④◗✡ß❊◆P➱❛❘❊Ï■✍✃✝❐➩◆P■❦➮✣➱❛✃✵✃✵■✍❋▲❑❊❏❲❒P❃➱❛❋✢◗❭▼⑧◗❇❒P■✍✃①◗❄❏✦◆P■ ❘➩■✍❃❋❊Ð✝ç✱❃④❑⑧■✍Ï▼✢❏❛❑⑧➱❛ß⑧❒P■❦❑å❒P➱✝❈❊■✍Ïßà➮✣❖▲◗❇❒P➱❛✃✵■✍◆✽◗❄Ï➱⑧➮✍❏❲❒P■✮ß❊◆P➱⑧❑⑧❖▲➮❫❒✽◗❄❒P❈❊■✍▼✢ç✐➱❛❖❊Ï④❑åÏ ❃Ó❛■✮❒P➱ ß❊❖❊◆✽➮✽❈▲❏❛◗❭■❛ä❲èq❋①■❦◗P◗❭■✍❋▲➮✣■❛❐t❒P❈❊■❦◗❭■✖◗❭▼⑧◗❇❒P■✍✃①◗✼❏✦ß❊ß❊Ï▼✮❑❊❏❲❒✽❏❣❏✦❋▲❏✦Ï▼⑧◗❭❃④◗✕❒P■❦➮✽❈❊❋❊❃④Ñ♥❖❊■❦◗②❒P➱❣ß❊◆P➱❲Ò❉❃④❑⑧■ ❏①Ï ❃④◗❇❒❄➱✦❮✼◆P■❦➮✣➱❛✃✵✃✵■✍❋▲❑⑧■❦❑✝ß❊◆P➱⑧❑⑧❖▲➮❫❒✽◗✱❮➊➱❛◆❄■❦❏❛➮✽❈✿➱❛❋❊Ï ❃❋❊■✧➮✣❖▲◗❇❒P➱❛✃✵■✍◆❦ä➩æ✸❈❊■✧✃✵➱♥◗❇❒✖❮❾❏✦✃✵➱❛❖▲◗ ■✣é❊❏✦✃✵ß❊Ï■✿❃❋✫■✣❅q➮✣➱❛✃✵✃✵■✍◆✽➮✣■✝❘❊❖▲◗❭❃❋❊■❦◗P◗❭■❦◗✵❃④◗①❒P❈❊■✫ê❛ë②ì❉í❫îqï❲ð①ñ✣ò✽í✝ó✕ô❊ïöõ✽ï❲ì❛÷tô❉î④øá❮➊■❦❏❲❒P❖❊◆P■ ❖▲◗❭■❦❑☞❃❋ Þ✃①❏✦❰✍➱❛❋✂ä ➮✣➱❛✃①ùtú❍❐❊ç✱❈❊❃④➮✽❈☞❃④◗✱❘▲❏❛◗❭❃④➮✍❏✦Ï Ï▼➢❏✦ß❊ß❊Ï ❃■❦❑➧❒P➱✵■✍Ò❛■✍◆P▼➢ß❊◆P➱⑧❑⑧❖▲➮❫❒✱ß▲❏✦Ð❛■➽➱❛❋ ❃❒✽◗➽ç✐■✍❘▲◗❭❃❒P■❦◗✍ä➤û✫❃❒P❈✢❒P❈❊■✵❈❊■✍Ïß✢➱✦❮❍❒P❈❊❃④◗✡❮➊■❦❏❲❒P❖❊◆P■❛❐ Þ✃①❏✦❰✍➱❛❋✂ä ➮✣➱❛✃①ùtú✐ü ◗➽◗❭▼⑧◗❇❒P■✍✃✘◆P■❦➮✣➱❛✃✮❅ ✃✵■✍❋▲❑❊◗✱◗❭❃✃✵❃ Ï④❏✦◆✸ß❊◆P➱⑧❑⑧❖▲➮❫❒✽◗❍❒P➱✧❒P❈❊■❣➮✣❖❊◆P◆P■✍❋♥❒✸❘❊❖❊▼❛■✍◆✸❘▲❏❛◗❭■❦❑➢➱❛❋➧❒P❈❊■➽ß❊❖❊◆✽➮✽❈▲❏❛◗❭■✡❈❊❃④◗❇❒P➱❛◆P❃■❦◗ ➱✦❮②ß❊◆P■✍Ò❉❃➱❛❖▲◗✸➮✣❖▲◗❇❒P➱❛✃✵■✍◆✽◗✸ç✱❈❊➱✵❘➩➱❛❖❊Ð❛❈♥❒✸❒P❈❊■✛◗P❏✦✃✵■➽ß❊◆P➱⑧❑⑧❖▲➮❫❒❦ä ý ➠②✇♥❵ ❞✂❩❇❳✽❞q❳❫❬✣❩❇♦❭✇❣✇❉❬✍❞✂➝⑧❳✽❳✽❚❄✉④♠♥❚❉❪❛❳❫❪✡❵❚❣❧❉❬✣❩q❱✈➝❲❝✡þ✱❜❛ÿ✵❨✍❩❭❬✍❚❲❱❇❞✕❽✈❽✕❤✈❸❯⑨t❺❦❹✍⑨✁￾✣❺❦❹✛➸➀❙q❴①❜♥❤✿❽➛❤✟➻ ❬✍❚❉❪å❙❡➠➛❸❯❶❦❶❦❷t❹✍❷t❹✍❻✦⑤②þ✐❙❯➨❍❸❾þ✸⑥➤❴ ➛❶✁￾P❸❯⑥➤❴✵❶✄✂✍❶❦❻✁￾❦⑤②♣✐⑦➛✆☎⑦ ❬✍❚❉❪år✱❜❛⑦✐ÿö♠♥❚❉❪❛❳P❩❣❬✍❨✍❩❇❳✽❳P❸ ❢❣❳✽❚❲❱❄❚❛❩❫➟✂ÿ✞✝❦❶❦❻❦❶t❹❫❸❯⑨❦⑨✣❸✟￾P❸❯❶t❺❦❹✣❼❛⑤✟❬✍❚❉❪✿♠♥❚❛❩❇❳✽❞❡❱q❩❇❵ ♦P❱❇❳❫❪✿♦❫❬✍❞q✇✡✠✣❳☞☛❲♠♥❵❧♥❢❣❳✽❚❲❱❄❨❦❵✉❱❇❞➽✉❩❇❥❦❢✥þ✱❤➛⑤ ❙✍✌✟❴➧⑤♥❙❯❚❲❱❇❳✽③▲❬✍❚❉❪①❜✦r✐þ✡➟