Using Markov Chains for Link Prediction in Adaptive Web Sites

Transcription

1 Ug Marov Cha for L Predto Adaptve Web Ste Jaha Zhu, Ju Hog, ad Joh G. Hughe Shool of Iforato ad Software Egeerg, Uverty of Ulter at Jordatow Newtowabbey, Co. Atr, BT37 QB, UK {h.zhu,.hog, g.hughe}@ult.a.u Abtrat. The large uber of Web page o ay Web te ha raed avgatoal proble. Marov ha have reetly bee ued to odel uer avgatoal behavor o the World Wde Web (WWW). I th paper, we propoe a ethod for otrutg a Marov odel of a Web te baed o pat vtor behavor. We ue the Marov odel to ae l predto that at ew uer to avgate the Web te. A algorth for trato probablty atrx opreo ha bee ued to luter Web page wth lar trato behavor ad opre the trato atrx to a optal ze for effet probablty alulato l predto. A axal forward path ethod ued to further prove the effey of l predto. L predto ha bee pleeted a ole yte alled ONE (Ole Navgato Explorer) to at uer avgato the adaptve Web te. Itroduto I a Web te wth a large uber of Web page, uer ofte have avgatoal queto, uh a, Where a I? Where have I bee? ad Where a I go? []. Web brower, uh a Iteret Explorer, are qute helpful. The uer a he the URI addre feld to fd where they are. Web page o oe Web te alo have a herarhal avgato bar, whh how the urret Web loato. Soe Web te how the uer urret poto o a teap. I IE 5.5, the uer a he the htory lt by date, te, or ot vted to fd where he/he ha bee. The htory a alo be earhed by eyword. The uer a batra where he/he ha bee by lg the Ba butto or eletg fro the htory lt attahed to the Ba butto. Hyperl are how a dfferet olor f they pot to prevouly vted page. We a ee that the awer to the frt two queto are atfatory. To awer the thrd queto, what the uer a do to loo at the l the urret Web page. O the other had, ueful forato about Web uer, uh a ther teret dated by the page they have vted, ould be ued to ae predto o the page that ght teret the. Th type of forato ha ot bee fully utlzed to provde a atfatory awer to the thrd queto. A good Web te hould be able to help t uer to fd awer to all three queto. The aor goal of th paper to provde a adaptve Web te [] that hage t preetato ad orgazato o the ba of l predto to help uer fd the awer to the thrd queto. D. Butard, W. Lu, ad R. Sterrtt (Ed.): Soft-Ware, LNCS 3, pp. 6 73,. Sprger-Verlag Berl Hedelberg

2 Ug Marov Cha for L Predto Adaptve Web Ste 6 I th paper, by vewg the Web uer avgato a Web te a a Marov ha, we a buld a Marov odel for l predto baed o pat uer vt behavor reorded the Web log fle. We aue that the page to be vted by a uer the future are detered by h/her urret poto ad/or vtg htory the Web te. We otrut a l graph fro the Web log fle, whh ot of ode repreetg Web page, l repreetg hyperl, ad weght o the l repreetg the uber of traveral o the hyperl. By vewg the weght o the l a pat uer plt feedba of ther preferee the hyperl, we a ue the l graph to alulate a trato probablty atrx otag oe-tep trato probablte the Marov odel. The Marov odel further ued for l predto by alulatg the odtoal probablte of vtg other page the future gve the uer urret poto ad/or prevouly vted page. A algorth for trato probablty atrx opreo ued to luter Web page wth lar trato behavor together to get a opat trato atrx. The opreed trato atrx ae l predto ore effet. We further ue a ethod alled Maxal Forward Path to prove the effey of l predto by tag to aout oly a equee of axally oeted page a uer vt [3] the probablty alulato. Fally, l predto tegrated wth a prototype alled ONE (Ole Navgato Explorer) to at Web uer avgato the adaptve Web te. I Seto, we derbe a ethod for buldg a Marov odel for l predto fro the Web log fle. I Seto 3, we du a algorth for trato atrx opreo to luter Web page wth lar trato behavor for effet l predto. I Seto 4, l predto baed o the Marov odel preeted to at uer avgato a prototype alled ONE (Ole Navgato Explorer). Experetal reult are preeted Seto 5. Related wor dued Seto 6. I Seto 7, we olude the paper ad du future wor. Buldg Marov Model fro Web Log Fle We frt otrut a l truture that repreet page, hyperl, ad uer traveral o the hyperl of the Web te. The l truture the ued to buld a Marov odel of the Web te. A tradtoal ethod for otrutg the l truture Web rawlg, whh a Web dexg progra ued to buld a dex by followg hyperl otuouly fro Web page to Web page. Weght are the aged to the l baed o uer traveral [4]. Th ethod ha two drawba. Oe that oe rrelevat page ad l, uh a page outde the urret Web te ad l ever travered by uer, are evtably luded the l truture, ad eed to be fltered out. Aother that the Webater a et up the Web te to exlude the rawler fro rawlg to oe part of the Web te for varou reao. We propoe to ue the l forato otaed a ECLF (Exteded Coo Log Fle) [5] forat log fle to otrut a l truture, alled a l graph. Our approah ha two advatage over rawlg-baed ethod. Oly relevat page ad l are ued for l graph otruto, ad all the page relevat to uer vt are luded the l graph.

3 6 J. Zhu, J. Hog, ad J.G. Hughe. L Graph A Web log fle ota rh reord of uer requet for douet o a Web te. ECLF forat log fle are ued our approah, e the URI of both the requeted douet ad the referrer datg where the requet ae fro are avalable. A ECLF log fle repreeted a a et of reord orrepodg to the page requet, WL ={( e, e,..., e )}, where e, e,..., e are the feld eah reord. A reord a ECLF log fle ght loo le a how Fgure : [4/Apr/999::: +] "GET /tudaffar/apu.htl HTTP/." 537 " "Mozlla/4. (opatble; MSIE 4.; Wdow 95)" Fg.. ECLF Log Fle The reord of ebedded obet the Web page, ludg graphal, vdeo, ad audo fle, are treated a redudat requet ad reoved, e every requet of a Web page wll tate a ere of requet of all the ebedded obet t autoatally. The reord of uueful requet are alo darded a erroeou reord, e there ay be bad l, g or teporarly aeble douet, or uauthorzed requet et. I our approah, oly the URI of the requeted Web page ad the orrepodg referrer are ued for l graph otruto. We therefore have a plfed et WL ={( ru)},, where r ad u are the URI of the referrer ad r the requeted page repetvely. Se varou uer ay have followed the ae l ther vt, the traveral of thee l are aggregated to get a et WL ={( ruw)},,, where w the uber of traveral fro r to u. I ot ae a l the hyperl fro r to u. Whe - the referrer feld, we aue there a vrtual l fro - to the requeted page. We all eah eleet ( ruw),, the et a l par. Two l par l =( r, u, w ) ad l =( r, u, w ) are ad to be oeted f ad oly f r = r, r = u, u = r, or u = u. A l par et LS ={( r, u, w )} ad to oet to aother l par et LS ={( r, u, w )} f ad oly f for every l par l LS, there ext a l par l LS, o that l ad l are oeted. Defto. (Maxally oeted L par Set) Gve a l par et WL ={( r, u, w )}, ad a l par et LS ={( r, u, w )} WL, we ay LS ={( r, u, w )} o l l l WL f ad oly f WL the Maxally oeted L par Set (MLS) of LS oet to LS, ad for every l par LS l ( WL - LS ), { l } ad LS are ot oeted. For a Web te wth oly oe aor etrae, the hoepage, people a oe to t varou way. They ght oe fro a page o aother Web te potg to the hoepage, follow a earh reult retured by a earh ege potg to the

4 Ug Marov Cha for L Predto Adaptve Web Ste 63 hoepage. - the referrer feld of a page requet reord date that the uer ha typed the URI of the hoepage dretly to the addre feld of the brower, eleted the hoepage fro h/her booar, or led o a hortut to th hoepage. I all thee ae the referrer forato ot avalable. We elet a et of l par LS ={( r, u, w )}, where r -, the URI of a page o aother Web te, or the URI of a earh reult retured by a earh ege, u the URI of the hoepage, ad w the weght o the l, a the etrae to the herarhy. We the loo for the Maxally oeted L par Set (MLS) LS of LS for the eod level of the herarhy. We loo for LS of LS WL - LS to WL - LS - LS. Th proe otue utl we get LS, o that WL - LS ={} or LS + ={}. = For a Web te wth a gle etrae, we wll ooly fh the l graph otruto wth ( WL - = LS )={}, whh ea that every l par ha bee put oto a erta level the herarhy. The level the herarhy are fro LS to LS. For a Web te wth everal etrae, ooly foud ult-futoal Web te, the otruto wll ed wth LS + ={} whle ( WL - elet a l par et forg aother etrae fro ( WL - eparate l graph. = LS = ) {}. We a the LS ) to otrut a Defto. (L Graph) The l graph of WL, a dreted weghted graph, a herarhy otg of ultple level, LS,, LS,, LS, where r u w )}, LS the MLS of LS WL - LS, ad WL - LS ={} LS ={(,, or LS + ={}. We add the Start ode to the l graph a the tartg pot for the uer vt to the Web te ad the Ext ode a the edg pot of the uer vt. I order to eure that there a dreted path betwee ay two ode the l graph, we add a l fro the Ext ode to the Start ode. Due to the fluee of ahg, the aout of weght o all og l of a page ght ot be the ae a the aout of weght o all outgog l. To olve th proble, we a ether ag extra og weght to the l to the tart/ext ode or dtrbute extra outgog weght to the og l. Fgure how a l graph we have otruted ug a Web log fle at the Uverty of Ulter Web te, whh the ttle of eah page how bede the ode repreetg the page. = =

5 64 J. Zhu, J. Hog, ad J.G. Hughe Uverty of Ulter CS 8 Departet See Iforato Studet 3 Iteratoal Lbrary Uder- Offe graduate 5 &Art Graduate Start 9 S E Job 8 Regter 8 Ext Fg.. A L Graph Cotruted fro a Web Log Fle o Uverty of Ulter Web Ste. Marov Model Eah ode the l graph a be vewed a a tate a fte drete Marov odel, whh a be defed by a tuple < S, Q, L >, where S the tate pae otag all the ode the l graph, Q the probablty trato atrx otag oe-tep trato probablte betwee the ode, ad L the tal probablty dtrbuto o the tate S. The uer avgato the Web te a be ee a a tohat proe { X }, whh ha S a the tate pae. If the ( ) odtoal probablty of vtg page the ext tep, P, depedet oly o the lat page vted by the uer, { X } alled a -order Marov ha [8]. ( ) Gve that the uer urretly at page ad ha vted page,...,, P oly, depedat o page,,...,. + ( ) P = P( X = X =, X =,..., X = ) =, + () PX ( = X = X, =,..., X = ) + + +,

6 Ug Marov Cha for L Predto Adaptve Web Ste 65 where the odtoal probablty of X + gve the tate of all the pat evet equal to the odtoal probablty of X + gve the tate of the pat evet. Whe =, X + depedet oly o the urret tate X. P = P (),, = PX ( = X = ) a oe-order Marov ha, where P the probablty +, that a trato ade fro tate to tate oe tep. We a alulate the oe-tep trato probablty fro page to page ug a l graph a follow, by oderg the larty betwee a l graph ad a rut ha dued [7]. The oe-tep trato probablty fro page to page, P, a be vewed a the frato of traveral fro to, over the total uber of traveral fro to other page ad the Ext ode. P = P( X = X =, X =,..., X = ) = PX ( = X = ) = + +, w, w, () where w the weght o the l fro to, ad w the weght o a l,, fro to. Now a probablty trato atrx, whh repreet the oe-tep trato probablty betwee ay two page, a be fored. I a probablty trato atrx, row ota oe-tep trato probablte for to all tate. Row u up to.. Colu ota oe-tep trato probablte fro all tate to. The trato atrx alulated fro the l graph Fgure how Fgure 3. \ Page Page Ext Start Ext.. Start. Fg. 3. Trato Probablty Matrx for the L Graph Fg.

7 66 J. Zhu, J. Hog, ad J.G. Hughe 3 Trato Matrx Copreo A algorth, that a be ued to opre a pare probablty trato atrx, preeted [5] whle the trato behavor of the Marov odel are preerved. State wth lar trato behavor are aggregated together to for ew tate. I l predto, we eed to rae the trato atrx Q to the th power. For a large Q th oputatoally expeve. Spear algorth a be ued to opre the orgal atrx Q to a uh aller atrx Q wthout gfat error e the auray experet o large atre have how that Q ad ( Q ) are very loe to eah other. Se the oputatoal oplexty of Q 3 ON ( ), by draatally redug N, the te tae by opreo a be opeated by all ubequet probablty oputato for l predto [5]. We have ued Spear algorth our approah. The larty etr of every par of tate fored to eure thoe par of tate that are ore lar hould yeld le error whe they are opreed [5]. Baed o the larty etr [5], the trato larty of two page ad a produt of ther -l ad out-l larte. Ther -l larty the weghted u of dtae betwee olu ad olu at eah row. Ther out-l larty the u of dtae betwee row ad row at eah olu. S = S ( out l) S ( l),,, S ( out l) = α ( y), y, S ( l) β ( x) =, x, α ( y) = P P,, y, y P P β ( x) =, + where x, x, = P, P l l, l l, ad = are the u of the probablte o the -l of page ad repetvely, S ( out l) the u of the out-l probablty dfferee, betwee ad, S ( l) the u of -l probablty dfferee, betwee ad. For the trato atrx Fgure 3, the alulated trato larty atrx how Fgure 4. If the larty loe to zero, the error reulted fro opreo loe to zero [5]. We a et a threhold ε, ad let S < ε to loo for addate page for, ergg. (3)

8 Ug Marov Cha for L Predto Adaptve Web Ste 67 \ Page Page Ext Start Ext Start Fg. 4. Trato Slarty Matrx for Trato Matrx Fg. 3 (Syetr) By rag ε we a opre ore tate wth a oeurate reae error. Page harg ore -l, out-l, ad havg equvalet weght o the wll eet the larty threhold. Suppoe tate ad are erged together, we eed to ag trato probablte betwee the ew tate ad the reag tate the trato atrx. We opute the weghted average of the th ad th row ad plae the reult the row of tate, ad u the th ad th olu ad plae the reult the olu of tate. P = P + P,,, P, P + P = +,, (4) For the larty atrx Fgure 4, we et the larty threhold ε =.. Experet dated a value of ε betwee.8 ad.5 yelded good opreo wth al error for our l graph. The opreo proe how Fgure 5. State ad 4, 5 ad 6 are opreed a a reult of S ( l) =, tate 8, 9,, ad are opreed a a reult of S ( out l) =., The opreed atrx how Fgure 6. The opreed atrx deer tha the orgal trato atrx. Whe ether S ( out l) = or S ( l) =, the opreo wll,, reult o error: Error = ad, Q = ( Q ) [5]. So there o opreo error for the trato atrx Fgure 4 ad t opreed atrx Fgure 6. There ay ot alway be the ae for a trato atrx alulated fro aother l graph. Whe S below a gve threhold, the effet of opreo o the trato,

9 68 J. Zhu, J. Hog, ad J.G. Hughe behavor of the tate ( ( Q ) Q ) wll be otrolled, the trato property of the atrx preerved ad the yte opreed to a optal ze for probablty oputato. The opreed trato atrx ued for effet l predto. Copreed tate 4 to tate (larty.)(tate: 4) Copreed tate 6 to tate 5 (larty.)(tate: 5 6) Copreed tate 9 to tate 8 (larty.)(tate: 8 9) Copreed tate to tate (larty.)(tate: ) Copreed tate to tate 8 (larty.)(tate: 8 9 ) Fhed opreo. Have opreed 4 tate to 9. Fg. 5. Copreo Proe for Trato Matrx Fg. 3 \ Page Page (,4) 3 (5,6) 7 (8,9,,) Ext Start.7.3 (, 4) (5, 6) (8,9,,).. Ext. Start. Fg. 6. Copreed Trato Matrx for Trato Matrx Fgure 3 4 L Predto Ug Marov Cha Whe a uer vt the Web te, by tag the page already vted by h/her a a htory, we a ue the opreed probablty trato atrx to alulate the probablte of vtg other page or luter of page by h/her the future. We vew eah opreed tate a a luter of page. The alulated odtoal probablte a be ued to etate the level of teret of other page ad/or luter of page to h/her. 4. L Predto o M-Order N-Step Marov Cha Sarua [4] propoed to ue the l htory of a uer to ae l predto. Suppoe a uer urretly at page, ad h/her vtg htory a a equee of page {,,..., }. We ue vetor L + + ={ l }, where l = whe = ad l = otherwe, for the urret page, ad vetor L ={ l } ( =,..., + ),

10 Ug Marov Cha for L Predto Adaptve Web Ste 69 where l = whe = ad l = otherwe, for the prevou page. Thee htory vetor are ued together wth the trato atrx to alulate vetor Re for the probablty of eah page to be vted the ext tep a follow: Re = a L Q+ a L Q a L Q (5) + where a, a,... a are the weght aged to the htory vetor. The value of a, a,... a date the level of fluee the htory vetor have o the future. Norally, we let > a > a >... > a >, o that the loer the htory vetor to the preet, the ore fluee t ha o the future. Th ofor to the obervato of a uer avgato the Web te. Re ={ re } oralzed, ad the page wth probablte above a gve threhold are eleted a the reoedato. We propoe a ew ethod a a proveet to Sarua ethod by alulatg the poblte that the uer wll arrve at a tate the opreed trato atrx wth the ext tep. We alulate the weghted u of the poblte of arrvg at a partular tate the trato atrx wth the ext tep gve the uer htory a h/her overall poblty of arrvg at that tate the future. Copared wth Sarua ethod, our ethod a predt ore tep the future, ad thu provde ore ght to the future. We alulate a vetor Re repreetg the probablty of eah page to be vted wth the ext tep a follow: Re = a L Q+ a L Q a L Q +,,, a L Q + a L Q a L Q ,,, a L Q + a L Q a L Q +, +, +, + (6) a, a,..., a,..., a, a,..., a are the weght aged to the where,,,,,, htory vetor L,, L +,,,,,,, + tep to the future, repetvely. Norally, we let > a, > a, >... > a, > ( =,,, ), o that for eah htory vetor, the loer t trato to the ext tep, the ore portat t otrbuto. We alo let > a, > a, >... > a l l, > ( l =,,, ), l o that the loer the htory vetor to the preet, the ore fluee t ha o the future. Re ={ re } oralzed, ad the page wth probablte above a gve threhold are eleted a the reoedato. 4. Maxal Forward Path Baed L Predto A axal forward path [3] a equee of axally oeted page a uer vt. Oly page o the axal forward path are odered a a uer htory for

11 7 J. Zhu, J. Hog, ad J.G. Hughe l predto. The effet of oe baward referee, whh are aly ade for eae of travel, fltered out. I Fg. 3, for tae, a uer ay have vted the Web page a equee 5 6. Se the uer ha vted page 5 after page ad the goe ba to page order to go to page 6, the urret axal forward path of the uer : 6. Page 5 darded the l predto. 5 Experetal Reult Experet were perfored o a Web log fle reorded betwee t ad 4 th of Otober, 999 o the Uverty of Ulter Web te, whh 37 MB ze ad ota,93,998 ae reord. After dardg the rrelevat reord, we get 43,739 reord. I order to rule out the poblty that oe l are oly teretg to dvdual uer, we et a threhold a the u uber of traveral o eah hyperl a ad there ut be three or ore uer who have travered the hyperl. We aue eah orgatg ahe orrepod to a dfferet uer. Thee ay ot alway be true whe uh a proxy erver ext. But the abee of uer trag oftware, the ethod a tll provde rather relable reult. We the otrut a l graph otg of 75 ode, ad 387 l betwee the ode. The otruto proe tae 6 ute o a Petu 3 detop, wth a 6 MHz CPU, 8M RAM. The axu uber of traveral o a l the l graph,336, whh o the l fro the Start ode to the hoepage of the Web te. The axu ad average uber of l a page the l graph are 75 ad.47 repetvely. The axu uber of -l of a page the l graph 57. The trato atrx ad very pare. By ettg x dfferet threhold for opreo, we get the experetal reult gve Table : Table. Copreo Reult o a Trato Matrx fro a Web Log Fle ε Copreo Te Sze after opreo % of tate reoved (Mute) We a ee that whe ε reae, the atrx beoe harder to opre. For th atrx, we hooe ε =.5 for a good opreo rate wthout gfat error. Experet [5] alo how that a value of ε =.5 yelded good opreo wth u error. Now we alulate Q ad ue the te pet a the behar for Q. Se we a repeatedly ultply Q by Q to get Q,, Q, Q, the te pet for oputg Q,, Q, Q a be etated a the te of the te for. Table uare the experetal reult of oputato for Q

12 Ug Marov Cha for L Predto Adaptve Web Ste 7 Q. We a ee that the te eeded for opreo opeated by the te aved the oputato for Q. Whe alulatg Q, oputatoal te a be further redued. Q,, Q a be oputed off-le ad tored for l predto. So the repoe te ot a ue gve the fat developg oputatoal apablty of the Web erver. Table. Experetal Reult for Q ad Q Matrx Deo( ) Coputato Te for Q or Q (Mute) Peretage of te aved (%) N/A We the ue the opreed trato atrx for l predto. L predto tegrated wth a prototype alled ONE (Ole Navgato Explorer) to at uer avgato our uverty Web te. ONE provde the uer wth foratve ad foued reoedato ad the flexblty of beg able to ove aroud wth the htory ad reoeded page. The average te eeded for updatg the reoedato uder 3 eod, o t utable for ole avgato, gve the repoe a be peeded up wth the urret oputatoal apablty of ay oeral Web te. We eleted =5 ad =5 l predto to tae to aout fve htory vetor the pat ad fve tep the future. We oputed 9 Q,, Q for l predto. The tal feedba fro our group eber very potve. They have pet le te to fd tereted forato ug ONE tha ot ug ONE our uverty Web te. They have ore uefully foud the forato ueful to the ug ONE tha ot ug ONE. So uer avgato ha bee effetvely peeded up ug ONE. ONE preet a lt of Web page a the uer vtg htory alog wth the reoeded page updated whle the uer travere the Web te. Eah te whe a uer requet a ew page, probablte of vtg ay other Web page or page luter wth the ext tep are alulated. The the Web page ad luter wth the hghet probablte are hghlghted the ONE wdow. The uer a browe the luter ad page le the Wdow Explorer. Io are ued to repreet dfferet tate of page ad luter. Le the Wdow Explorer, ONE allow the uer to atvate page, expad luter. Eah page gve t ttle to derbe the otet the page. 6 Related Wor Raeh Sarua [4] ha dued the applato of Marov ha to l predto. Uer' avgato regarded a a Marov ha for l aaly. The trato probablte are alulated fro the auulated ae reord of pat uer. Copared wth h ethod, we have three aor otrbuto. We have

13 7 J. Zhu, J. Hog, ad J.G. Hughe opreed the trato atrx to a optal ze to ave the oputato te of Q +, whh a ave a lot of te ad reoure gve the large uber of Web page o a oder Web te. We have proved the l predto alulato by tag to aout ore tep the future to provde ore ght to the future. We have propoed to ue Maxal Forward Path ethod to prove the auray of l predto reult by elatg the effet of baward referee by uer. The Adaptve Web Ste approah ha bee propoed by Perowtz ad Etzo []. Adaptve Web te are Web te whh a autoatally hage ther preetato ad orgazato to at uer avgato by learg fro Web uage data. Perowtz ad Etzo propoed the PageGather algorth to geerate dex page opoed of Web page ot ofte aoated wth eah other uer vt fro Web uage data to evaluate a Web te orgazato ad at uer avgato []. Our wor the otext of adaptve Web te. Copared wth ther wor, our approah ha two advatage. () The dex page baed o o-ourree of page uer pat vt ad doe ot tae to aout uer vtg htory. The dex page a tat reoedato. Our ethod ha tae to aout uer htory to ae l predto. The l predto dya to reflet the hagg teret of the uer. () I PageGather, t aued that eah orgatg ahe orrepod to a gle uer. The aupto a be udered by proxy erver, dya IP alloato, whh are both oo o the WWW. Our ethod treat a uer group a a whole wthout the detfato of dvdual uer ad thu ore robut to thee fluee. However, oputato eeded l predto ad the reoedato a ot repod a quly a the dex page, whh a be dretly retreved fro a Web erver. Spear [5] propoed a trato atrx opreo algorth baed o trato behavor of the tate the atrx. Trato atre alulated fro yte, whh are beg odeled too ay detal, a be opreed for aller tate pae whle the trato behavor of the tate are preerved. The algorth ha bee ued to eaure the trato larte betwee page our wor ad opre the probablty trato atrx to a optal ze for effet l predto. Proll ad Ptow [3] tuded the web urfer' traverg path through the WWW ad propoed to ue a Marov odel for predtg uer' l eleto baed o pat uer' urfg path. Albreht et al. [] propoed to buld three type of Marov odel fro Web log fle for pre-edg douet. Myra Splopoulou [6] dued ug avgato patter ad equee aaly ed fro the Web log fle to peroalze a web te. Mobaher, Cooley, ad Srvatava [4, 9] dued the proe of g Web log fle ug three d of luterg algorth for te adaptato. Brulovy [] gave a opreheve revew of the tate of the art adaptve hypereda reearh. Adaptve hypereda lude adaptve preetato ad adaptve avgato upport []. Adaptve Web te a be ee a a d of adaptve preetato of Web te to at uer avgato. 7 Coluo Marov ha have bee prove very utable for odelg Web uer avgato o the WWW. Th paper preet a ethod for otrutg l graph fro Web log

14 Ug Marov Cha for L Predto Adaptve Web Ste 73 fle. A trato atrx opreo algorth ued to luter page wth lar trato behavor together for effet l predto. The tal experet how that the l predto reult preeted a prototype ONE a help uer to fd forato ore effetly ad aurately tha ply followg hyperl to fd forato the Uverty of Ulter Web te. Our urret wor ha opeed everal frutful dreto a follow: () Maxal forward path ha bee utlzed to approxately fer a uer purpoe h/her avgato path, whh ght ot be aurate. The l predto a be further proved by detfyg uer goal eah vt [6]. () L predto ONE eed to be evaluated by a larger uer group. We pla to elet a group of uer ludg tudet, taff our uverty, ad people fro outde our uverty to ue ONE. Ther terato wth ONE wll be logged for aaly. (3) We pla to ue Web log fle fro oe oeral Web te to buld a Marov odel for l predto ad evaluate the reult o dfferet uer group. Referee. Albreht, D., Zuera, I., ad Nholo, A.: Pre-edg Douet o the WWW: A Coparatve Study. IJCAI99 (999). Brulovy, P.: Adaptve hypereda. Uer Modelg ad Uer Adapted Iterato (/). () Che, M. S., Par, J. S., Yu, P. S.: Data g for path traveral a web evroet. I Pro. of the 6th Itl. Coferee o Dtrbuted Coputg Syte, Hog Kog. (996) 4. Cooley, R., Mobaher, B., ad Srvatava, J. Data Preparato for Mg World Wde Web Browg Patter. Joural of Kowledge ad Iforato Syte, Vol., No.. (999) 5. Halla-Baer, P. M. ad Behledorf, B.: Exteded Log Fle Forat. W3C Worg Draft WD-logfle (996) 6. Hog, J.: Graph Cotruto ad Aaly a a Paradg for Pla Reogto. Pro. of AAAI-: Seveteeth Natoal Coferee o Artfal Itellgee, () Kalpazdou, S.L. Cyle Repreetato of Marov Proee, Sprger-Verlag, NY. (995) 8. Ka, M.: Marov Proee for Stohat Modelg. Chapa&Hall, Lodo. (997) 9. Mobaher, B., Cooley, R., Srvatava, J.: Autoat Peroalzato Through Web Uage Mg. TR99-, Dept. of Coputer See, Depaul Uverty. (999). Nele, J.: Degg Web Uablty, New Rder Publhg, USA. (). Perowtz, M., Etzo, O.: Adaptve web te: a AI hallege. IJCAI97 (997). Perowtz, M., Etzo, O.: Toward adaptve Web te: oeptual fraewor ad ae tudy. WWW8. (999) 3. Proll, P., Ptow, J. E.: Dtrbuto of Surfer Path Through the World Wde Web: Epral Charaterzato. World Wde Web : -7. (999) 4. Sarua, R.R.: L predto ad path aaly ug Marov ha. WWW9, () 5. Spear, W. M.: A opreo algorth for probablty trato atre. I SIAM Matrx Aaly ad Applato, Volue, #. (998) Splopoulou, M.: Web uage g for te evaluato: Mag a te better ft t uer. Co. ACM Peroalzato Tehologe wth Data Mg, 43(8). () 7-34