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Trend Makers and Trend Spotters
        in a Mobile Application




                                     Xiaolan Sha?
                                 Daniele Quercia?
                                Pietro Michiardi?
                               Matteo Dell¡¯Amico?


                  ?EURECOM ?Yahoo! Research Barcelona
Who create trends?
Two-Step Flow




Mass Media



        In?uentials
             Normal
444    Accidental Influentials                                                       JOURNAL OF CON

                         FIGURE 2                                 of these assumptions is demonstrabl
                                                                  clearly correct either¡ªthe empirical ev
     SCHEMATIC OF NETWORK MODEL OF INFLUENCE
                                                                  inconclusive. Thus we will also presen
                                                                  variations of the basic model that relax
                                                                  and the randomness assumptions.
                                                                      Another advantage of formally de?
                                                                  work, even with such a simple mod
                                                                  de?ne more precisely what we mea
                                                                  Previous empirical work has address
                                                                  should be considered in?uential, b
                                                                  mains elusive (Weimann 1991). Clas
                                                                  of Coleman et al. (1957) and Merton
                                                                  individuals who directly in?uence m
                                                                  of their peers should be considered
                                                                  cent market research studies have co
                                                                  ber may be as high as 14 (Burson-M
                                                                  studies, by contrast, de?ne in?uent
                                                                  terms: Keller and Berry (2003), fo
                                                                  ?uentials as scoring in the top 10%
                                                                  ership test, while Coulter et al. (2002
                                                                  treat the top 32% as in?uentials.
                                                                      Here we follow the latter approac
                                                                  ential as an individual in the top q%
                                                                  tribution p (n). From a theoretical pers
                                                                  value of q that we specify is necessa
                                                                  we have already argued that dichoto
                                                                  tween opinion leaders and followers a
1 in?uence can only ?ow from opinion leaders to fol-              derived nor empirically supported. O
lowers, in ?gure 2, it can ?ow in either direction. Second,       ever, is not to defend any particular d
in ?gure 2 in?uence can propagate for many steps,       [D. Watts,but to examine the claim that in?uen
                                                                   P. Dodds JSTOR 2007]
whereas in ?gure 1 it can propagate only two. We note,            reasonable, self-consistent manner¡ª
however, that, in both cases, ?gure 2 is consistent with          of diffusion processes. From this pers
available empirical evidence¡ªarguably more so than ?g-            de?nition has the advantage (over d
ure 1. Numerous studies, including that of Katz and La-           absolute numbers) that it can be app
Context
Dataset



                                                         Users
                                technology-savvy, design-conscious


                                                    Pictures
                     technology, lifestyle, music, design and fashion



9,316 users uploaded 6,395 pictures and submitted 13,893 votes.
Identification


                                                     Trends
                                A simple burst detection method


                                   Spotters/Makers
        Spotter Score: how many, early, popular of the trends
                                     Maker Score: how often


                                         Typical Users
All active users (>=2 votes/uploads) who is not spotter or a maker.



                   140 Makers; 671 Spotters; 1,705 Typical Users
Characterizations



                      Features
                             Activity
                            Content
                            Network
                         Geographical


                Hypotheses
   [Kolmogorov-Smirnov tests]
     Spotters/Makers vs. Typical Users
                 Spotters vs. Makers
Results




Spotters/Makers vs. Typical users
                              More active, more popular


                   Spotters vs. Makers
     More votes, less uploads,wider spectrum of interests
Prediction



                   Features




    £û
                   Activity

                   Content          Trend Spotters
Every User
                   Social Network    Trend Makers

      User Space   Geography                User Space
Predictors




                                                                                                                                                Follower Geo Span
                                                                                             Upload Diversity
                                                               Daily Uploads




                                                                                                                  Vote Diversity
                                                                               Daily Votes




                                                                                                                                   Wandering




                                                                                                                                                                    #Followers


                                                                                                                                                                                 #Followees
                                                   Life Time
                                          Age
                           Life Time       0.21
  Activity             Daily Uploads       0.02     -0.12
                         Daily Votes       0.05     -0.09        0.47 ?
                    Upload Diversity       0.02     0.09         0.40 ?          0.08
 Content               Vote Diversity      0.04     0.08         0.22            0.08           0.42 ?
                         Wandering         0.004    0.13         0.16            0.11           0.06                0.05
Geographical      Follower Geo Span        0.05     0.12         0.16            0.10           0.12                0.11            0.23
                          #Followers       0.03     0.23         0.37 ?          0.14           0.22                0.16            0.44           0.16
                          #Followees       0.05     0.17         0.52 ?          0.31 ?         0.29 ?              0.22            0.56 ?         0.21              0.64 ?
 Network          Network Clustering       0.03     0.13         0.22            0.04           0.24                0.23            -0.001         0.27 ?            0.08         0.22

                         Spotter Score     0.07     0.18         0.03            0.01           0.05                0.10            0.04           0.07              0.13         0.11        0.15
                          Maker Score      0.07     0.10         0.06            0.01           0.07                0.06            0.02           0.12              0.12         0.09        0.10
         Table 5. Pearson Correlation coef?cients between each pair of predictors. Coef?cients greater than ¡À0.25 with statistical signi?cant level < 0.05 are
         marked with a ?.


         Practical Implications                                                                                 CONCLUSION
         The ability of identifying trend spotters and trend makers has                                         A community is an emergent system. It forms from the ac-
         implications in designing recommender systems, marketing                                               tions of its members who are reacting to each other¡¯s behav-
         campaigns, new products, privacy tools, and user interfaces.                                           ior. Here we have studied a speci?c community of individuals
                                                                                                                who are passionate about sharing pictures of items (mainly
         Recommender Systems. Every user has different interests                                                fashion and design items) using a mobile phone application.
         and tastes and, as such, might well bene?t from personalized                                           This community has a speci?c culture in which a set of habits,
         suggestions of content. These suggestions are automatically                                            attitudes and beliefs guide how its members behave. In it, we
         produced by so-called ¡°recommender systems¡±. Typically,
Prediction




True positive rate

                     0.8
                                                   S-logistic
                     0.4                           S-svm
                                                   M-logistic
                                                   M-svm
                     0.0




                           0.0   0.2   0.4   0.6     0.8   1.0

                                 False positive rate
y trend spot-
                   Age                                     2e-04        0.001
 preliminary       Life Time                               0.006 *      0.001 *
ers opens up              Successful Spotters/Makers
                   Daily Votes (Daily Uploads)             0.007 *       0.16 *
ferences be-       Vote Diversity (Upload Diversity)        0.38 *       0.14 *
                   Wandering                              -6e-15       -7e-15
                   #Followers                              2e-05        0.009 *
                   Network Clustering                       0.08         0.28 *
 no previous
 spotters and
l hypotheses                            (b) Linear Regression
er that trend      Features                                 log(Score)
  tend to vote                                          Spotters   Makers
compared to        Age                                     0.36 *      0.01
 (H3.1), vote      Life Time                               0.19 *   0.0001
                   Daily Votes (Daily Uploads)             0.16           -
                                                                      -1.03 *
 ote more di-      Vote Diversity (Upload Diversity)       7.28 *         -
                                                                      -1.09 *
 ). After run-     Wandering                           -2.1e-13   -1.4e-15
nd that trend      #Followers                             -0.06        0.01 *
 ers who, by       Network Clustering                      2.75           -
                                                                      -0.64 *
oth H3.1 and       R2                                      0.15        0.65
 ote, we ?nd       Adjusted R2                             0.14        0.64
oad and vote
 s vote items
 kers act in a   Table 3. Coef?cients of the linear regression. A correlation coef?cient
d in [20, 18]    within 2 standard errors is considered statistically signi?cant. We high-
                 light and mark them with *.
ality content.
  items in the
 le they vote    of followees, daily uploads, daily votes, and content diver-
 de spectrum
Summary




                                            Successful Spotters
                  Early adopters who vote items from various categories.


                                              Successful Makers
Users who upload items belonging to speci?c categories, tend to be followed by
                                     users from different social clusters.
Conclusions




                                          Who Create Trends?

Regular individual with speci?c interests connected with early adopters with
                                                             diverse interests.
Questions?

More Related Content

Trend Makers and Trend Spotters in a Mobile Application

  • 1. Trend Makers and Trend Spotters in a Mobile Application Xiaolan Sha? Daniele Quercia? Pietro Michiardi? Matteo Dell¡¯Amico? ?EURECOM ?Yahoo! Research Barcelona
  • 3. Two-Step Flow Mass Media In?uentials Normal
  • 4. 444 Accidental Influentials JOURNAL OF CON FIGURE 2 of these assumptions is demonstrabl clearly correct either¡ªthe empirical ev SCHEMATIC OF NETWORK MODEL OF INFLUENCE inconclusive. Thus we will also presen variations of the basic model that relax and the randomness assumptions. Another advantage of formally de? work, even with such a simple mod de?ne more precisely what we mea Previous empirical work has address should be considered in?uential, b mains elusive (Weimann 1991). Clas of Coleman et al. (1957) and Merton individuals who directly in?uence m of their peers should be considered cent market research studies have co ber may be as high as 14 (Burson-M studies, by contrast, de?ne in?uent terms: Keller and Berry (2003), fo ?uentials as scoring in the top 10% ership test, while Coulter et al. (2002 treat the top 32% as in?uentials. Here we follow the latter approac ential as an individual in the top q% tribution p (n). From a theoretical pers value of q that we specify is necessa we have already argued that dichoto tween opinion leaders and followers a 1 in?uence can only ?ow from opinion leaders to fol- derived nor empirically supported. O lowers, in ?gure 2, it can ?ow in either direction. Second, ever, is not to defend any particular d in ?gure 2 in?uence can propagate for many steps, [D. Watts,but to examine the claim that in?uen P. Dodds JSTOR 2007] whereas in ?gure 1 it can propagate only two. We note, reasonable, self-consistent manner¡ª however, that, in both cases, ?gure 2 is consistent with of diffusion processes. From this pers available empirical evidence¡ªarguably more so than ?g- de?nition has the advantage (over d ure 1. Numerous studies, including that of Katz and La- absolute numbers) that it can be app
  • 6. Dataset Users technology-savvy, design-conscious Pictures technology, lifestyle, music, design and fashion 9,316 users uploaded 6,395 pictures and submitted 13,893 votes.
  • 7. Identification Trends A simple burst detection method Spotters/Makers Spotter Score: how many, early, popular of the trends Maker Score: how often Typical Users All active users (>=2 votes/uploads) who is not spotter or a maker. 140 Makers; 671 Spotters; 1,705 Typical Users
  • 8. Characterizations Features Activity Content Network Geographical Hypotheses [Kolmogorov-Smirnov tests] Spotters/Makers vs. Typical Users Spotters vs. Makers
  • 9. Results Spotters/Makers vs. Typical users More active, more popular Spotters vs. Makers More votes, less uploads,wider spectrum of interests
  • 10. Prediction Features £û Activity Content Trend Spotters Every User Social Network Trend Makers User Space Geography User Space
  • 11. Predictors Follower Geo Span Upload Diversity Daily Uploads Vote Diversity Daily Votes Wandering #Followers #Followees Life Time Age Life Time 0.21 Activity Daily Uploads 0.02 -0.12 Daily Votes 0.05 -0.09 0.47 ? Upload Diversity 0.02 0.09 0.40 ? 0.08 Content Vote Diversity 0.04 0.08 0.22 0.08 0.42 ? Wandering 0.004 0.13 0.16 0.11 0.06 0.05 Geographical Follower Geo Span 0.05 0.12 0.16 0.10 0.12 0.11 0.23 #Followers 0.03 0.23 0.37 ? 0.14 0.22 0.16 0.44 0.16 #Followees 0.05 0.17 0.52 ? 0.31 ? 0.29 ? 0.22 0.56 ? 0.21 0.64 ? Network Network Clustering 0.03 0.13 0.22 0.04 0.24 0.23 -0.001 0.27 ? 0.08 0.22 Spotter Score 0.07 0.18 0.03 0.01 0.05 0.10 0.04 0.07 0.13 0.11 0.15 Maker Score 0.07 0.10 0.06 0.01 0.07 0.06 0.02 0.12 0.12 0.09 0.10 Table 5. Pearson Correlation coef?cients between each pair of predictors. Coef?cients greater than ¡À0.25 with statistical signi?cant level < 0.05 are marked with a ?. Practical Implications CONCLUSION The ability of identifying trend spotters and trend makers has A community is an emergent system. It forms from the ac- implications in designing recommender systems, marketing tions of its members who are reacting to each other¡¯s behav- campaigns, new products, privacy tools, and user interfaces. ior. Here we have studied a speci?c community of individuals who are passionate about sharing pictures of items (mainly Recommender Systems. Every user has different interests fashion and design items) using a mobile phone application. and tastes and, as such, might well bene?t from personalized This community has a speci?c culture in which a set of habits, suggestions of content. These suggestions are automatically attitudes and beliefs guide how its members behave. In it, we produced by so-called ¡°recommender systems¡±. Typically,
  • 12. Prediction True positive rate 0.8 S-logistic 0.4 S-svm M-logistic M-svm 0.0 0.0 0.2 0.4 0.6 0.8 1.0 False positive rate
  • 13. y trend spot- Age 2e-04 0.001 preliminary Life Time 0.006 * 0.001 * ers opens up Successful Spotters/Makers Daily Votes (Daily Uploads) 0.007 * 0.16 * ferences be- Vote Diversity (Upload Diversity) 0.38 * 0.14 * Wandering -6e-15 -7e-15 #Followers 2e-05 0.009 * Network Clustering 0.08 0.28 * no previous spotters and l hypotheses (b) Linear Regression er that trend Features log(Score) tend to vote Spotters Makers compared to Age 0.36 * 0.01 (H3.1), vote Life Time 0.19 * 0.0001 Daily Votes (Daily Uploads) 0.16 - -1.03 * ote more di- Vote Diversity (Upload Diversity) 7.28 * - -1.09 * ). After run- Wandering -2.1e-13 -1.4e-15 nd that trend #Followers -0.06 0.01 * ers who, by Network Clustering 2.75 - -0.64 * oth H3.1 and R2 0.15 0.65 ote, we ?nd Adjusted R2 0.14 0.64 oad and vote s vote items kers act in a Table 3. Coef?cients of the linear regression. A correlation coef?cient d in [20, 18] within 2 standard errors is considered statistically signi?cant. We high- light and mark them with *. ality content. items in the le they vote of followees, daily uploads, daily votes, and content diver- de spectrum
  • 14. Summary Successful Spotters Early adopters who vote items from various categories. Successful Makers Users who upload items belonging to speci?c categories, tend to be followed by users from different social clusters.
  • 15. Conclusions Who Create Trends? Regular individual with speci?c interests connected with early adopters with diverse interests.