{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T10:50:26Z","timestamp":1781175026789,"version":"3.54.1"},"reference-count":60,"publisher":"Association for Computing Machinery (ACM)","issue":"1","license":[{"start":{"date-parts":[[2019,2,21]],"date-time":"2019-02-21T00:00:00Z","timestamp":1550707200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"TU Graz Open Access Publishing Fund"}],"content-domain":{"domain":["dl.acm.org"],"crossmark-restriction":true},"short-container-title":["Trans. Soc. Comput."],"published-print":{"date-parts":[[2019,3,31]]},"abstract":"<jats:p>Millions of users on the Internet discuss a variety of topics on Question-and-Answer (Q8A) instances. However, not all instances and topics receive the same amount of attention, as some thrive and achieve self-sustaining levels of activity, while others fail to attract users and either never grow beyond being a small niche community or become inactive. Hence, it is imperative to not only better understand but also to distill deciding factors and rules that define and govern sustainable Q8A instances. We aim to empower community managers with quantitative methods for them to better understand, control, and foster their communities, and thus contribute to making the Web a more efficient place to exchange information. To that end, we extract, model, and cluster a user activity-based time series from 50 randomly selected Q8A instances from the Stack Exchange network to characterize user behavior. We find four distinct types of user activity temporal patterns, which vary primarily according to the users\u2019 activity frequency. Finally, by breaking down total activity in our 50 Q8A instances by the previously identified user activity profiles, we classify those 50 Q8A instances into three different activity profiles. Our parsimonious categorization of Q8A instances aligns with the stage of development and maturity of the underlying communities, and can potentially help operators of such instances: We not only quantitatively assess progress of Q8A instances, but we also derive practical implications for optimizing Q8A community building efforts, as we, e.g., recommend which user types to focus on at different developmental stages of a Q8A community.<\/jats:p>","DOI":"10.1145\/3301612","type":"journal-article","created":{"date-parts":[[2019,2,22]],"date-time":"2019-02-22T17:01:44Z","timestamp":1550854904000},"page":"1-23","update-policy":"https:\/\/doi.org\/10.1145\/crossmark-policy","source":"Crossref","is-referenced-by-count":9,"title":["Activity Archetypes in Question-and-Answer (Q8A) Websites\u2014A Study of 50 Stack Exchange Instances"],"prefix":"10.1145","volume":"2","author":[{"given":"Tiago","family":"Santos","sequence":"first","affiliation":[{"name":"Graz University of Technology, Graz, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Simon","family":"Walk","sequence":"additional","affiliation":[{"name":"Detego GmbH, Graz, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roman","family":"Kern","sequence":"additional","affiliation":[{"name":"Graz University of Technology 8 Know-Center, Graz, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Markus","family":"Strohmaier","sequence":"additional","affiliation":[{"name":"RWTH Aachen University 8 GESIS, Aachen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Denis","family":"Helic","sequence":"additional","affiliation":[{"name":"Graz University of Technology, Graz, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"320","published-online":{"date-parts":[[2019,2,21]]},"reference":[{"key":"e_1_2_1_1_1","doi-asserted-by":"publisher","DOI":"10.1145\/1367497.1367587"},{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.is.2015.04.007"},{"key":"e_1_2_1_3_1","doi-asserted-by":"publisher","DOI":"10.1145\/2339530.2339665"},{"key":"e_1_2_1_4_1","doi-asserted-by":"publisher","DOI":"10.1145\/2488388.2488398"},{"key":"e_1_2_1_5_1","volume-title":"Proceedings of the 18th Annual ACM-SIAM Symposium on Discrete Algorithms. Society for Industrial and Applied Mathematics, 1027--1035","author":"Arthur David","year":"2007","unstructured":"David Arthur and Sergei Vassilvitskii . 2007 . k-means++: The advantages of careful seeding . In Proceedings of the 18th Annual ACM-SIAM Symposium on Discrete Algorithms. Society for Industrial and Applied Mathematics, 1027--1035 . David Arthur and Sergei Vassilvitskii. 2007. k-means++: The advantages of careful seeding. In Proceedings of the 18th Annual ACM-SIAM Symposium on Discrete Algorithms. Society for Industrial and Applied Mathematics, 1027--1035."},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1023\/A:1010933404324"},{"key":"e_1_2_1_7_1","volume-title":"Olshen","author":"Breiman Leo","year":"1984","unstructured":"Leo Breiman , Jerome Friedman , Charles J. Stone , and Richard A . Olshen . 1984 . Classification and Regression Trees. CRC press . Leo Breiman, Jerome Friedman, Charles J. Stone, and Richard A. Olshen. 1984. Classification and Regression Trees. CRC press."},{"key":"e_1_2_1_8_1","doi-asserted-by":"publisher","DOI":"10.1145\/2481492.2481493"},{"key":"e_1_2_1_9_1","volume-title":"Proceedings of the 4th International AAAI Conference on Weblogs and Social Media (ICWSM'10)","author":"Chan Jeffrey","unstructured":"Jeffrey Chan , Conor Hayes , and Elizabeth M. Daly . 2010. Decomposing discussion forums and boards using user roles . In Proceedings of the 4th International AAAI Conference on Weblogs and Social Media (ICWSM'10) . 215--218. Jeffrey Chan, Conor Hayes, and Elizabeth M. Daly. 2010. Decomposing discussion forums and boards using user roles. In Proceedings of the 4th International AAAI Conference on Weblogs and Social Media (ICWSM'10). 215--218."},{"key":"e_1_2_1_10_1","first-page":"07717","article-title":"Distributed and parallel time series feature extraction for industrial big data applications","volume":"1610","author":"Christ Maximilian","year":"2016","unstructured":"Maximilian Christ , Andreas W. Kempa-Liehr , and Michael Feindt . 2016 . Distributed and parallel time series feature extraction for industrial big data applications . Arxiv Preprint Arxiv : 1610 . 07717 . Maximilian Christ, Andreas W. Kempa-Liehr, and Michael Feindt. 2016. Distributed and parallel time series feature extraction for industrial big data applications. Arxiv Preprint Arxiv:1610.07717.","journal-title":"Arxiv Preprint Arxiv"},{"key":"e_1_2_1_11_1","doi-asserted-by":"publisher","DOI":"10.1145\/2512938.2512954"},{"key":"e_1_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.1145\/2566486.2568036"},{"key":"e_1_2_1_13_1","doi-asserted-by":"publisher","DOI":"10.1145\/2488388.2488416"},{"key":"e_1_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1145\/2910575"},{"key":"e_1_2_1_15_1","volume-title":"Proceedings of the 2nd International Conference on Knowledge Discovery and Data Mining (KDD'96)","author":"Ester Martin","year":"1996","unstructured":"Martin Ester , Hans-Peter Kriegel , J\u00f6rg Sander , Xiaowei Xu , 1996 . A density-based algorithm for discovering clusters in large spatial databases with noise . In Proceedings of the 2nd International Conference on Knowledge Discovery and Data Mining (KDD'96) . AAAI Press, 226--231. Martin Ester, Hans-Peter Kriegel, J\u00f6rg Sander, Xiaowei Xu, et al. 1996. A density-based algorithm for discovering clusters in large spatial databases with noise. In Proceedings of the 2nd International Conference on Knowledge Discovery and Data Mining (KDD'96). AAAI Press, 226--231."},{"key":"e_1_2_1_16_1","doi-asserted-by":"publisher","DOI":"10.1145\/191843.191925"},{"key":"e_1_2_1_17_1","volume-title":"Applied Regression Analysis and Generalized Linear Models","author":"Fox John","unstructured":"John Fox . 2015. Applied Regression Analysis and Generalized Linear Models . Sage Publications . John Fox. 2015. Applied Regression Analysis and Generalized Linear Models. Sage Publications."},{"key":"e_1_2_1_18_1","volume-title":"Workshop Notes of KDD2001 Workshop on Temporal Data Mining. AAAI Press, 26--36","author":"Ng Vincent","year":"2001","unstructured":"Tak-chung Fu, Fu-lai Chung, Vincent Ng , and Robert Luk . 2001 . Pattern discovery from stock time series using self-organizing maps . In Workshop Notes of KDD2001 Workshop on Temporal Data Mining. AAAI Press, 26--36 . Tak-chung Fu, Fu-lai Chung, Vincent Ng, and Robert Luk. 2001. Pattern discovery from stock time series using self-organizing maps. In Workshop Notes of KDD2001 Workshop on Temporal Data Mining. AAAI Press, 26--36."},{"key":"e_1_2_1_19_1","doi-asserted-by":"publisher","DOI":"10.1098\/rsif.2013.0048"},{"key":"e_1_2_1_20_1","doi-asserted-by":"publisher","DOI":"10.1145\/2441776.2441916"},{"key":"e_1_2_1_21_1","doi-asserted-by":"publisher","DOI":"10.1002\/meet.1450430171"},{"key":"e_1_2_1_22_1","doi-asserted-by":"publisher","DOI":"10.1080\/13614560701711917"},{"key":"e_1_2_1_23_1","doi-asserted-by":"publisher","DOI":"10.1109\/ICPR.2008.4761105"},{"key":"e_1_2_1_24_1","doi-asserted-by":"publisher","DOI":"10.1145\/2736277.2741664"},{"key":"e_1_2_1_25_1","doi-asserted-by":"publisher","DOI":"10.1145\/1459352.1459356"},{"key":"e_1_2_1_26_1","volume-title":"Rousseeuw","author":"Kaufman Leonard","year":"2009","unstructured":"Leonard Kaufman and Peter J . Rousseeuw . 2009 . Finding Groups in Data : An Introduction to Cluster Analysis. Vol. 344 . John Wiley 8 Sons. Leonard Kaufman and Peter J. Rousseeuw. 2009. Finding Groups in Data: An Introduction to Cluster Analysis. Vol. 344. John Wiley 8 Sons."},{"key":"e_1_2_1_27_1","doi-asserted-by":"publisher","DOI":"10.5555\/2993947.2993982"},{"key":"e_1_2_1_28_1","doi-asserted-by":"publisher","DOI":"10.1145\/1014052.1014077"},{"key":"e_1_2_1_29_1","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-0266(199606)17:6<441::AID-SMJ819>3.0.CO;2-G"},{"key":"e_1_2_1_30_1","first-page":"19","article-title":"Power of the few vs. wisdom of the crowd: Wikipedia and the rise of the bourgeoisie","volume":"1","author":"Kittur Aniket","year":"2007","unstructured":"Aniket Kittur , Ed Chi , Bryan A Pendleton , Bongwon Suh , and Todd Mytkowicz . 2007 . Power of the few vs. wisdom of the crowd: Wikipedia and the rise of the bourgeoisie . WWW 1 , 2 (2007), 19 . Aniket Kittur, Ed Chi, Bryan A Pendleton, Bongwon Suh, and Todd Mytkowicz. 2007. Power of the few vs. wisdom of the crowd: Wikipedia and the rise of the bourgeoisie. WWW 1, 2 (2007), 19.","journal-title":"WWW"},{"key":"e_1_2_1_31_1","doi-asserted-by":"publisher","DOI":"10.1145\/3041021.3051116"},{"key":"e_1_2_1_32_1","doi-asserted-by":"publisher","DOI":"10.1140\/epjb\/e2015-60481-x"},{"key":"e_1_2_1_33_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-642-31454-4_14"},{"key":"e_1_2_1_34_1","volume-title":"Proceedings of the IIE Annual Conference. Institute of Industrial Engineers-Publisher, 1.","author":"Liao T Warren","year":"2004","unstructured":"T Warren Liao . 2004 . Clustering of vector time series with fuzzy c-means . In Proceedings of the IIE Annual Conference. Institute of Industrial Engineers-Publisher, 1. T Warren Liao. 2004. Clustering of vector time series with fuzzy c-means. In Proceedings of the IIE Annual Conference. Institute of Industrial Engineers-Publisher, 1."},{"key":"e_1_2_1_35_1","doi-asserted-by":"publisher","DOI":"10.1109\/TIT.1982.1056489"},{"key":"e_1_2_1_36_1","doi-asserted-by":"publisher","DOI":"10.1145\/1978942.1979366"},{"key":"e_1_2_1_37_1","doi-asserted-by":"publisher","DOI":"10.1145\/1518701.1518821"},{"key":"e_1_2_1_38_1","doi-asserted-by":"crossref","unstructured":"N. Perra B. Gon\u00e7alves R. Pastor-Satorras and A. Vespignani. 2012. Activity driven modeling of time varying networks. Sci. Rep. 2 (2012).  N. Perra B. Gon\u00e7alves R. Pastor-Satorras and A. Vespignani. 2012. Activity driven modeling of time varying networks. Sci. Rep. 2 (2012).","DOI":"10.1038\/srep00469"},{"key":"e_1_2_1_39_1","doi-asserted-by":"publisher","DOI":"10.1145\/2566486.2567984"},{"key":"e_1_2_1_40_1","doi-asserted-by":"publisher","DOI":"10.1016\/0377-0427(87)90125-7"},{"key":"e_1_2_1_41_1","doi-asserted-by":"publisher","DOI":"10.1145\/3041021.3051117"},{"key":"e_1_2_1_42_1","doi-asserted-by":"publisher","DOI":"10.5555\/2487085.2487104"},{"key":"e_1_2_1_43_1","volume-title":"Proceedings of the 8th International AAAI Conference on Weblogs and Social Media (ICWSM'14)","author":"Solomon Jacob","year":"2014","unstructured":"Jacob Solomon and Rick Wash . 2014 . Critical mass of what? Exploring community growth in wikiprojects . In Proceedings of the 8th International AAAI Conference on Weblogs and Social Media (ICWSM'14) . AAAI Press, 476--484. Jacob Solomon and Rick Wash. 2014. Critical mass of what? Exploring community growth in wikiprojects. In Proceedings of the 8th International AAAI Conference on Weblogs and Social Media (ICWSM'14). AAAI Press, 476--484."},{"key":"e_1_2_1_44_1","doi-asserted-by":"publisher","DOI":"10.1145\/2934687"},{"key":"e_1_2_1_45_1","doi-asserted-by":"publisher","DOI":"10.1145\/2808797.2809331"},{"key":"e_1_2_1_46_1","volume-title":"Retrieved","author":"Community StackExchange","year":"2017","unstructured":"StackExchange Area 51 Community . 2017 . Tridion area 51 report . Retrieved February 13, 2017 from http:\/\/area51.stackexchange.com\/proposals\/38335\/tridion. StackExchange Area 51 Community. 2017. Tridion area 51 report. Retrieved February 13, 2017 from http:\/\/area51.stackexchange.com\/proposals\/38335\/tridion."},{"key":"e_1_2_1_47_1","volume-title":"Proceedings of the KDD Workshop on Text Mining","volume":"400","author":"Steinbach Michael","year":"2000","unstructured":"Michael Steinbach , George Karypis , Vipin Kumar , 2000 . A comparison of document clustering techniques . In Proceedings of the KDD Workshop on Text Mining , Vol. 400 . Boston, 525--526. Michael Steinbach, George Karypis, Vipin Kumar, et al. 2000. A comparison of document clustering techniques. In Proceedings of the KDD Workshop on Text Mining, Vol. 400. Boston, 525--526."},{"key":"e_1_2_1_48_1","doi-asserted-by":"publisher","DOI":"10.1145\/1641309.1641322"},{"key":"e_1_2_1_49_1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevE.73.036127"},{"key":"e_1_2_1_50_1","volume-title":"Proceedings of the Workshop on Clustering High Dimensionality Data and Its Applications. 23--30","author":"Vlachos Michail","year":"2003","unstructured":"Michail Vlachos , Jessica Lin , Eamonn Keogh , and Dimitrios Gunopulos . 2003 . A wavelet-based anytime algorithm for k-means clustering of time series . In Proceedings of the Workshop on Clustering High Dimensionality Data and Its Applications. 23--30 . Michail Vlachos, Jessica Lin, Eamonn Keogh, and Dimitrios Gunopulos. 2003. A wavelet-based anytime algorithm for k-means clustering of time series. In Proceedings of the Workshop on Clustering High Dimensionality Data and Its Applications. 23--30."},{"key":"e_1_2_1_51_1","doi-asserted-by":"publisher","DOI":"10.1145\/2873060"},{"key":"e_1_2_1_52_1","doi-asserted-by":"publisher","DOI":"10.1080\/01621459.1963.10500845"},{"key":"e_1_2_1_53_1","doi-asserted-by":"publisher","DOI":"10.1198\/jasa.2010.tm09415"},{"key":"e_1_2_1_54_1","volume-title":"Proceedings of the International Workshop on Complex Networks and their Applications. Springer, 353--364","author":"W\u00f6lbitsch Matthias","year":"2017","unstructured":"Matthias W\u00f6lbitsch , Simon Walk , and Denis Helic . 2017 . Modeling peer influence in time-varying networks . In Proceedings of the International Workshop on Complex Networks and their Applications. Springer, 353--364 . Matthias W\u00f6lbitsch, Simon Walk, and Denis Helic. 2017. Modeling peer influence in time-varying networks. In Proceedings of the International Workshop on Complex Networks and their Applications. Springer, 353--364."},{"key":"e_1_2_1_55_1","doi-asserted-by":"publisher","DOI":"10.1145\/1935826.1935863"},{"key":"e_1_2_1_56_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-319-08786-3_23"},{"key":"e_1_2_1_57_1","volume-title":"Proceedings of the 2016 IEEE 16th International Conference on Data Mining (ICDM). IEEE, 1317--1322","author":"Michael Yeh Chin-Chia","year":"2016","unstructured":"Chin-Chia Michael Yeh , Yan Zhu , Liudmila Ulanova , Nurjahan Begum , Yifei Ding , Hoang Anh Dau , Diego Furtado Silva , Abdullah Mueen , and Eamonn Keogh . 2016 . Matrix profile I: All pairs similarity joins for time series: A unifying view that includes motifs, discords and shapelets . In Proceedings of the 2016 IEEE 16th International Conference on Data Mining (ICDM). IEEE, 1317--1322 . Chin-Chia Michael Yeh, Yan Zhu, Liudmila Ulanova, Nurjahan Begum, Yifei Ding, Hoang Anh Dau, Diego Furtado Silva, Abdullah Mueen, and Eamonn Keogh. 2016. Matrix profile I: All pairs similarity joins for time series: A unifying view that includes motifs, discords and shapelets. In Proceedings of the 2016 IEEE 16th International Conference on Data Mining (ICDM). IEEE, 1317--1322."},{"key":"e_1_2_1_58_1","doi-asserted-by":"publisher","DOI":"10.2196\/jmir.2501"},{"key":"e_1_2_1_59_1","doi-asserted-by":"publisher","DOI":"10.1145\/1242572.1242603"},{"key":"e_1_2_1_60_1","doi-asserted-by":"publisher","DOI":"10.5555\/3192424.3192509"}],"container-title":["ACM Transactions on Social Computing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/3301612","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.1145\/3301612","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,18]],"date-time":"2025-06-18T00:57:35Z","timestamp":1750208255000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/3301612"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,2,21]]},"references-count":60,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2019,3,31]]}},"alternative-id":["10.1145\/3301612"],"URL":"https:\/\/doi.org\/10.1145\/3301612","relation":{},"ISSN":["2469-7818","2469-7826"],"issn-type":[{"value":"2469-7818","type":"print"},{"value":"2469-7826","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,2,21]]},"assertion":[{"value":"2017-06-01","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2018-12-01","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2019-02-21","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}