Mediating Multi-Party Negotiation Through Marker-Based Tracking of Mobile Phones

Transcription

1 Mediting Multi-Prty Negotition Through Mrker-sed Trking of Moile Phones Mihel Rohs Deutshe Telekom Lortories TU erlin, Germny hristin Kry Informtis Reserh Institute Newstle University, STRT Negotiting dte nd time for meeting involving numer of people n e diffiult nd time-onsuming proess even when ll prtiipnts re olloted nd supported y tehnology. Oftentimes, it involves n ution-like proedure, where suggestions nd onflits re nnouned to the group nd then heked individully until fesile time n e found. We propose to use sptil proximity regions round hndheld devies to signifintly redue the effort of exploring proposed meeting times in the ontext of prty of olloted people. In order to determine the lotion of devies on tle, we hve developed new trking mehnism tht relies on dynmi visul mrkers shown on the sreen of the devies used. preliminry evlution of the underlying ide nd the trking mehnisms highlights dvntges nd drwks of our pproh. tegories nd Sujet Desriptors H.5.2 [Informtion Interfes nd Presenttion]: User Interfes input devies nd strtegies, intertion styles; H.5.3 [Informtion Interfes nd Presenttion]: Group nd Orgniztion Interfes omputer-supported oopertive work, synhronous intertion Generl Terms Design, Humn Ftors Keywords moile phones, mrker-sed trking, meeting support, situted intertion, tngile intertion, sptilly-wre interfes, sptil reltions. INTRODUTION Fe-to-fe meetings with usiness prtners or with ollegues within ompny onstitute n importnt prt of everydy tivities in the professionl lives of mny people. onsequently, people frequently need to gree on dte nd time when they ll will e ville to meet. This tsk n eome quite omplex if there re numer of people involved or if the prtiipnts re very usy, nd it my require severl rounds of negotition efore dte n e greed on. rnge of devies is ville to support users when engging in this proess, e. g. lptop omputers, PDs, nd moile phones. utomti solutions to the meeting negotition prolem hve only een prtilly suessful so fr [5], sine users often enter low-priority events or lok times in their lendrs tht n e used for meetings if needed. Moreover, mny users prefer to sty in ontrol of their time plnning rther thn delegting it to n utomti tool. In the ontext of this pper, we ssume tht ll prtiipnts mintin personl lendr using smrtphone or PD, nd tht the negotition tkes ple in lotion with one or more mers for trking phones on tle (e. g. resonly equipped meeting room). The tsk tht we im to support is the negotition prt of finding dte nd time for meeting, in prtiulr suggesting dte nd time to the group, jumping to suggested dte nd time in one s own lendr, nd epting/rejeting suggested dte nd time. To hieve this we use simple sptil gestures nd proximity regions round hndheld devies. The sptil reltionships of the involved devies reflet the negotition stte for proposed dte. The lotion of devie on the tle is determined vi new trking mehnism tht relies on dynmi visul mrkers shown on the devie sreen. The enefits of fine-grined sptil intertion for hndheld devies hve een reognized some time go [2], ut the ide hs een diffiult to implement. TRIP [] is visionsed lotion system using irulr mrkers. The mrkers re trked y mers instlled in the environment. It would e possile to show TRIP tgs on phone displys, ut their irulr form ftor would led to lot of wsted disply spe nd prevent simultneous disply of pplition dt. Relte [3, 4] is system for the detetion of sptil reltionships etween olloted moile devies. It does not require n infrstruture, ut determines reltive position nd orienttion vi ultrsound sensing implemented on US dongles. This pproh requires dditionl hrdwre on eh devie, wheres the mrker trking pproh presented here is softwre-only solution on the users side. Our pproh requires n externl infrstruture, ut hs higher ury nd updte rte. Doodle ( is n online tool for meeting negotition. The inititor proposes numer of dtes nd sends unique URL generted y the system to ll prtiipnts, who n then individully ept or deline the proposed dtes. This orresponds to one round of negotition in our system, leit with multiple proposed dtes. 2. PPROH In this setion we desrie our pproh to hieve the gols outlined ove. We first present nd motivte the si ide efore giving detiled desription of how we relized it tehnilly. We lso onduted preliminry evlution of oth spets, whih we disuss in setion 3.

2 2. si onept The si ide underlying our pproh is to use sptil proximity regions round moile phones to trigger prtiulr tions in response to other devies entering them, leving them, or stying within them for ertin mount of time. For the senrio t hnd, we define three regions round moile phone, nd ssign them to synhroniztion-relted tions in the ontext of the meeting negotition proess. Figure depits digrm of the different regions round moile devie. Figure 2: Multi-prty negotitions: () no ommitment s not ll devies re inside IPR of, () ommitment performed s ll devies re inside IPR. Figure : Proximity regions round sttionry moile phone; see text for explntion. We ll the region furthest from devie its distl region (DR). s long s devies re loted in this region reltive to devie, they re onsidered to e too fr wy for intertion nd do operte independently. In this stte, it is hene possile for the respetive owners of these devies to individully explore their personl lendr. The intertion is initited one devie enters the seond region round devie, whih we ll its outer proximl region (OPR). In this se, we ssume tht the owner of the moile phone hs seleted prtiulr dte nd time nd is proposing it to the group s potentil meeting time. The other memers of the group n then hek whether they re ville t tht time y moving their own devies lose to the devie of. One devie enters the OPR of devie, the lendr pplition on devie utomtilly jumps to the dte nd time tht is seleted on devie. The owner of devie n immeditely see whether the meeting time suggested y is still ville in their own lendr. y moving devie out of the OPR of nd into its DR, the lendr on devie reverts k to the stte it ws in efore entering the OPR of In order to onfirm suggested meeting time, devie needs to enter into nd remin within the region nerest to the devie proposing the dte nd time; we ll this region its inner proximl region (IPR). s shown in Figure, one devie enters the IPR of devie, it onfirms the suggested meeting time. User n ort the onfirmtion y moving devie out of the IPR of. If there re more thn two prties involved, ll devies need to e in the IPR of in order to onfirm the suggested dte nd time. s long s there re still prtiipting devies outside the IPR of, those inside the IPR will merely indite tht they re redy to ommit to the dte nd time ut will not ept it. Figure 2 illustrtes this ehvior: in se (), devie is still outside the IPR of. Therefore, the suggested dte is not yet epted. In se (), oth nd re inside the IPR of ; hene, the suggested meeting dte is epted y ll prtiipnts. The owner of devie n ort the intertion t ny stge y moving devie in ny diretion. (overing the visul mrker on the disply hs the sme effet s it effetively removes the devie from the system.) This lso invlidtes the suggested time/dte nd ll other devies within the proximl regions of devie revert k to the stte they were in prior to entering into different stges of ommitment. Tle summrizes the different tions nd the orresponding negotition stges. Tle : Sptil tions involving devies nd nd the negotition stges ssoited with them. Sptil tion in DR of in OPR of in IPR of moving into DR of moving while devie re in its OPR/IPR personl spe tle shred spe individul explortion Negotition stge no intertion, i. e. independent opertion displys dte/time seleted on (explortion) epts dte/time seleted on (ommitment) lso see text interrupts intertion interrupts intertion () propose, (2) hek 2 2 (3) ept, (4) deline Figure 3: Users,, t tle: (left) individul explortion of personl lendrs; (middle) proposes dte, nd hek the dte; (right) epts nd delines the proposed dte. n lterntive pproh to the one desried ove is to define regions with respet to the physil position of the persons involved. This helps to inrese slility to lrger tles nd groups, sine users do not hve to move their devies over long distne towrds to the proposing devie. 3 4

3 s shown in Figure 3 the re lose to user is defined s personl spe, in whih one s own lendr n e explored. y moving phone into the entrl region, user n propose meeting time. Other prtiipnts n explore the suggested time y moving their devies into the shred spe, ept it y moving them into the entrl re, or rejet it y moving their devie k into the personl spe. 2.2 Tehnil Reliztion The position nd orienttion of the phones is trked y dynmi visul mrker tht is displyed on the phone sreen (see Figure 4). The mrker is designed in suh wy tht it oupies only smll mount of sreen spe. In the prototype implementtion on Noki N95 with sreen size of pixels the mrker just oupies 5% of the sreen re. The mrker is pled t the top of the sreen in order to mke it unlikely tht users indvertently over the mrker with their hnds. The phone mrker stores 42 its of dt tht re proteted y (48,42,3) liner ode with Hmming distne of 3. For eh deteted mrker the reognition lgorithm provides the enoded vlue, enter position, rottion, nd distne. Figure 4: Visul mrker t the top of phone lendr pplition (left). Trking of two phones (right). Mrker vlues nd distne overlid. Figure 5 shows the lyout of mrker. It onsists of two squre orner stones surrounded y whitespe nd entrl dt re of 2 4 elements. The totl horizontl width of the mrker is 20 elements. The reognition lgorithm proeeds s follows: The grysle imge is thresholded to lk-nd-white imge. To find the orner stones onneted regions re omputed. Regions with n xis rtio figures.ppt greter thn 0.7 (minor to mjor xis length) nd pixel ount within ertin rnge re lssified s orner stone ndidtes. Then, mthing pirs of orner stones re identified. Idelly, mthing orner stones hve the sme size nd distne of 6 elements. Sine mrkers n pper tilted in the mer imge, we llow ±25% devition from the idel vlues of size nd distne. In order to smple the dt points of potentilly tilted mrker, homogrphy is omputed sed on four points ner the orner stones (indited y dimond shpes in Figure 5). These points re found y moving ±.5 elements in diretion perpendiuorner stone dt re (2 x 4 elements) orner stone thresholded mer imge with highlighted orner stones nd smple points in the dt re Figure 5: Elements of the visul mrker for disply on phone sreens (top) nd thresholded mer imge with highlighted strutures (ottom). lr to the onnetion vetor of the two orner stones. The smpled 48 points in the dt re then undergo prity hek. The resulting 42 dt its re reported together with the position of the mrker (in the oordinte system of the externl mer), its rottion, nd its distne (inverse of size multiplied y onstnt). Mrkers re trked y downwrd-fing mer mounted ove the tle. We used typil wem (Logiteh Quikm Fusion) with wide ngle lens (digonl ngle of out 70 ). The wide ing ngle mens tht the mer nnot e eiling-mounted ut t distnes etween m only. For eiling-mounted opertion telephoto lens would e needed. The trking softwre is implemented in Jv. Initilly we onneted the video strem vi the Jv Medi Frmework (JMF). While eing pltform independent, the drwks of this solution were the long dely (out 500 ms) nd the limited resolution (mximum pixels). We therefore swithed to Windows Diret- Show nd Jv Ntive Interfe (JNI). The dely is shorter nd higher resolutions re possile (up to pixels). Mrker sightings re reported vi luetooth to the phones onneted to the P. In the prototype implementtion eh phone omputes its distne to the losest mrker, determines wht proximity region it is in nd updtes its disply ordingly. 3. PRELIMINRY EVLUTION In order to evlute our pproh, we performed qulittive nlysis of the effort involved in negotiting meeting ompring our pproh to se se. In ddition, we ompiled n initil hrteriztion of the mrker-sed visul trking mehnism. t this stge, oth re preliminry ut nevertheless provide initil support for our pproh. We re lso plnning usility study t lter stge. 3. Qulittive nlysis of Effiieny s desried in setion, our im is to improve the negotition of meeting dte mong multiple people. We ssume tht they use moile devie (suh s moile phone) to mintin their personl lendr. We used the stndrd lendr pplition of high-end moile phone (Noki N95)

4 s se se. Figure 6 depits simplified stte digrm of the lendr pplition. In our nlysis, we disregrded ny shortuts tht were not essile/visile through the user interfe displyed on the sreen. In the figure, rrows orrespond to trnsitions etween sttes, nd the numers orrespond to the numer of key presses tht re needed to get from one stte to the other. For exmple, in order to ring up the form for reting new meeting on the dy seleted in month, four onseutive key presses re needed. There re two steps in prtiulr, for whih we wnt to redue the effort: exploring dte suggested y nother person in one s own lendr, s well s onfirming suggested meeting dte nd entering it into one s own lendr. month dy 4 3 week rete meeting Figure 6: Simplified stte digrm of the lendr pplition on moile phone (Noki N95); rrows re leled with the numer of key presses needed to get from one stte to the other. In order to estimte the time needed to omplete these tsks in the se se, we first need to determine the numer of key presses user hs to perform during this proess. This numer depends on severl ftors: the (month, week, dy) tht is urrently seleted the temporl distne etween the urrently seleted dy nd the suggested dte the numer of meetings tht re lredy sheduled for the suggested dte. oth month nd week re orgnized s 2D grids, whih the user n nvigte using the five-wy nvigtion utton. The dy is liner list, whih lso uses the nvigtion utton. We ssume tht only the dy enles the user to fully ssess whether time slot is ville for meeting or not. (The week offers only orse of time llotion ut does not provide detils out sheduled meetings suh s their ext strting nd end times.) sed on these onsidertions we n estimte the numer of key presses needed to nvigte to suggested dte (see Tle 2). It should e noted tht Tle only represents n estimte, nd tht there re dditionl key presses needed if the dy suggested lredy hs numer of meetings sheduled. The minimum numer of key presses n only e relized if t = t s; the further prt the dtes re, the more key presses re needed. ssuming optiml usge, there is n upper ound: y entering the pop-up menu nd seleting the go to dte option, users n enter trget dte numerilly. The ost inurred y this opertion is t lest 9 key presses ( if different month is suggested nd 5 if the suggested dte is in nother yer). We riefly explored the lendr tool tht omes preinstlled with mid-rnge phone (Sony Erisson K750i) nd found it to e very similr to the one on the N95. Tle 2: Key presses (KP) needed to nvigte from urrent dte t to suggested dte t s. key presses needed min month KP per every week t nd t s re KP prt KP per every dy in the week t nd t s re prt KP to enter dy week 7 KP per every full week t nd t s KP re prt KP per every dy in the week t nd t s re prt KP to enter dy dy KP per every dy t nd t s re 0 KP prt In order to illustrte the key presses needed to nvigte to suggested dte, let us onsider the following exmple. user is in month nd hs seleted Fridy, 22 June. nother person suggests Thursdy, 28 June s meeting dte. In this se, three key presses re required. In week seven key presses would e required, nd in dy six. If the suggested dte would hve een 2 July insted, five key presses would e required in month, 2 in week nd 20 in dy. In eh, dditionl key presses would e required in se the suggested dy lredy hs more meetings sheduled thn n shown t one. This lerly demonstrtes tht under ll ut optiml onditions (i. e. the suggested dte is the one lredy seleted) it is resonle to ssume tht user will hve to perform etween 3 nd 9 key presses, oftentimes more. In ddition, the originl stte will e lost. Returning to the dte tht ws originlly seleted inurs the sme numer of key presses gin. onsequently, the osts will e douled for every suggested dte tht is explored ut then rejeted. If dte is epted, further key presses re required. Depending on the the user is in t tht time, three or four key presses re needed to enter the form to rete meeting. In this form, user hs to fill in numer of fields (sujet, lotion, strt time, end time, et.). Minimlly, strt nd end time hve to e provided, whih results in t lest four key presses (if the utomtilly suggested times extly mth the proposed meeting times), respetively 4 individul key presses (if strt nd end time hve to e entered mnully). While it is diffiult to ompre key presses to gestures (i. e. moving devie on tle), Tle 3 illustrtes tht the proposed pproh is t lest less omplex for the user: single tion is required to nvigte to suggested dte, to rejet the suggestion nd return to the previously seleted dte, nd to ept suggested dte. In the se se senrio, user will lso hve to nvigte through numer of forms or menus, whih dds to the omplexity, wheres this is not the se in our pproh. Furthermore, if the user wnts to inlude dditionl informtion out the meeting (e. g. its sujet nd lotion), signifint numer of key presses will e required. Using our pproh, if the proposer inluded this informtion in the suggestion, this would not inur ny dditionl osts for other prtiipnts.

5 Tle 3: omplexity of intertion to perform single step of negotition. tsk se se our pproh explortion. 3 to 9 key presses gesture rejetion. 3 to 9 key presses gesture eptne. 4 to 4 key presses gesture 3.2 hrteriztion of Trking Mehnism Our experiments show tht the minimum size of mrker element is out 3 3 pixels in the mer imge. This mens tht the minimum required mrker width is 20 3 = 60 pixels. Sine the disply width of our prototype devie is 40 mm, the tle surfe must e smpled t minimum resolution of 60/40 =.5 pixels/mm. t mer resolution of pixels tle re of m n thus e overed y single mer. For roustness slightly smller physil re my e desirle. On noteook with.73 GHz Intel Pentium M nd G of min memory the verge proessing time of the lgorithm for imge is 5 ms, 37% of whih is due to thresholding. However, JNI nd other omponents introdue dditionl delys. Sine the mrker s orner stones re symmetril their orienttion hs to e heked y other mens. One possiility would e to reserve two dt elements s orienttion inditors. nother wy, whih is urrently implemented, is to use the error hek s n impliit orienttion indition. If the error hek fils in one diretion, the smpled its re reversed nd heked gin. Given tht the error proteting ode is not symmetri only one diretion will sueed. 4. DISUSSION fter presenting n initil evlution of the proposed pproh, we wnt to disuss numer of questions regrding the performne, fesiility nd other hrteristis of using visul mrkers in this wy. Does the pproh improve performne? s highlighted in the previous setion nd Tle 3 further experiments re needed to more preisely hrterize the performne of our pproh. It is however firly ler tht using our pproh signifintly simplifies the whole proess y reduing the omplexity of the intertion needed. In prtiulr, the ost of exploring suggested dtes is redued. Is the pproh suitle for meeting negotition? ssuming tht the dte nd time of meeting is oftentimes greed t the end of nother meeting, we would rgue tht it is resonly relisti to ssume setting where ll prtiipnts re olloted nd re using personl devies to ess their individul diries. typil meeting room usully provides tehnil infrstruture, whih might well inlude mer to reord meeting (e. g. the slides presented during the meeting) or equipment for video-onferening. Even if this not the se, the ost of dding simple wem re very low. sed on the rgument, outfitting more sul ples (suh s fé in usiness distrit of ig ity) would not e prohiitively expensive. How to del with privy issues? Oviously, mersed trking n pose thret to the privy of prtiipnts, i. e. the mer n reord the whole sreen ontent, potentilly exposing detils from individul diries. There re three different responses to this:. We ssume enevolent environment (e. g. meeting room owned y trusted prty). 2. We improve the overll seurity of the system. Exmples for this pproh inlude only showing mrkers on the sreen nd limiting the infrstruture to trking the lotion of the mrkers. 3. We eliminte the need for n infrstruture. n ide we pln to investigte would e to use the mer on the moile phone of prtiipnt. 5. SUMMRY In this pper, we presented novel pproh to negotite meeting times mong group of olloted prtiipnts. In order to relize it, we used proximity regions nd trking mehnism sed on new type of visul mrkers tht re eing displyed on the sreen of hndheld devies. We provided preliminry evlution, oth with respet to its intertion properties nd the hrteristis of the trking sheme. sed on these results, we disussed the enefits in terms of its performne nd fesiility for meeting negotition. We lso reed privy spets of our pproh. Due to the overll promising results, we intend to further develop the pproh nd to vlidte it in usility study. In ddition to the tul devie intertion, it would e very interesting to study the emedding of the pproh in the soil negotition protool nd to investigte ttention shifts etween devie nd fe-to-fe ommunition. potentil wy of mking the system independent of ny externl infrstruture would e to use the mer of prtiipnt s devie insted of one provided y the environment. Other spets we wnt to investigte re the use of dynmi mrkers s visul ommunition hnnel nd the use of the system for other pplitions involving proximity regions. 6. KNOWLEDGMENTS We would like to knowledge hrdwre grnt y Noki Reserh Ls, Finlnd tht provided the N95 hndsets used. We would lso like to thnk the orgnizers nd prtiipnts of the FTIR workshop in Münster, Germny, for inspiring disussions. 7. REFERENES [] D. L. de Ipiñ, P. R. S. Mendonç, nd. Hopper. TRIP: low-ost vision-sed lotion system for uiquitous omputing. Personl Uiquitous omput., 6(3):206 29, [2] G. W. Fitzmurie. Situted informtion spes nd sptilly wre plmtop omputers. ommun. M, 36(7):39 49, 993. [3] M. Hzs,. Kry, H. Gellersen, H. got, G. Kortuem, nd. Krohn. reltive positioning system for sptil wreness of o-loted moile devies nd users. In Proeedings of MoiSys 2005, pges 77 90, [4] G. Kortuem,. Kry, nd H. Gellersen. Sensing nd visulizing sptil reltions of moile devies. In Proeedings of UIST 2005, pges 93 02, [5] L. Plen. Soil, individul nd tehnologil issues for groupwre lendr systems. In Proeedings HI 99, pges 7 24, 999.