Categorizing and measuring social ties

he analysis of social networks has boomed recently, mainly as online social networking systems such as Twitter allow researchers to access these data. However, the research is less and less focused on the fundamental question on the validity of the data and interpretation of the results. For example, Golder et al. (2007) use the word 'friend' in quotes while describing their results. To enhance the discussion around the validity of results, our work contributes a categorization of social network data. We also discuss the differences of the data sources, especially highlighting the fact that different data sources disclose different kinds of networks. Our approach is to examine social networks based on several sources of data, and thus acquire a richer data set. Based on this extended data set, we are more equipped to understand the social relations represented via links between nodes. After reviewing the existing literature, we make two observations of social relationships in online services. Firstly, the friendship data may be shared in public or with the specific group of users of that service - this may affect how people perceive and use these relationships, especially when compared with the private displays of relations (e.g., Donath & boyd, 2004). On the other hand, people interact only with part of their social relations (e.g., Golder et al., 2007) and research has started to focus from statical networks to more dynamical activity based networks (e.g., Huberman et al., 2009). Based on the existing literature, shortly discussed above, a 2x2 matrix can be developed. Relations may be public or private and active or passive. For instance, those relations with which you use Instant Messaging can be considered private and active whereas Facebook friends are passive and public. As they are different in this nature, also the conclusions based on the analysis should differ. After confirming that the data measure the phenomenon desired, one should use several kinds of data sources to really understand the social structures behind the group under study. We claim that multiple data sets should be used when measuring social relations. McPherson et al. (2001) have also concluded that the priority for future social network researchers should be to gather dynamic data on multiple social relations. By studying existing research and our own empirical data (e.g., Karikoski & Nelimarkka, 2011), we discuss the opportunities and challenges of using multiple data sets to cover the same group.Peer reviewe

Scenarios and system dynamics of mobile peer-to-peer content distribution

Vertaisverkkoteknologian menestys kiinteissä verkoissa on johtanut vertaisverkkototeutuksiin myös mobiileissa verkoissa. Mobiilin vertaisverkkoteknologian tulevaisuuden suhteen on tosin vielä paljon epävarmuutta, koska operaattorit ja muut sidosryhmän jäsenet, jotka kärsivät laittoman tiedostonvaihdon seurauksista kiinteän verkon puolella, pelkäävät saman tapahtuvan myös mobiileissa verkoissa. Täten he saattavat yrittää estää mobiilin vertaisverkkoteknologian kehittymistä. On myös epävarmaa onko mobiilille vertaisverkkoteknologialle tarvetta loppukäyttäjän näkökulmasta, eritoten kun mobiililaitteiden suorituskyvyt ovat huomattavasti alhaisempia kuin kiinteiden. Tämä diplomityö keskittyy mobiilin vertaisverkon sisällönjakeluun. Sisällönjakelu on jaettu tiedostonvaihtoon, sisällön suoratoistoon ja kaupallisiin sisältöjärjestelmiin. Työ antaa näkemystä mobiilin vertaisverkon sisällönjakelun olennaisimpiin skenaarioihin, sidosryhmän jäseniin ja heidän kannustimiin. Mobiilin vertaisverkon sisällönjakelun epävarmuutta rajataan käyttämällä skenaarioanalyysiä ja mallinnetaan systeemidynamiikalla. Olennaisimmat skenaariot rakennetaan Schoemakerin metodilla ja niiden mallinnusta yritetään systeemidynamiikan keinoin. Tuloksena saadaan neljä eri skenaariota, jotka on kehitetty brainstorming -tilaisuuksissa ja kirjallisuuskatsauksessa löydettyjen avaintrendien ja -epävarmuustekijöiden perusteella. Skenaarioiden kvantitatiivisen mallinnuksen sijaan mallinnetaan skenaarioihin perustuvan mobiilin vertaisverkon sisällönjakelujärjestelmän dynaamista käyttäytymistä. Vaikka joitakin mobiilia vertaisverkkoteknologiaa hyödyntäviä sovelluksia on jo kehitetty ja käytössä, sekä aihetta tutkittu laajasti, vieläkin on epävarmaa mikä teknologian vaikutus tulee olemaan. Tämä diplomityö esittää mahdollisia vaikutuksia teknologialle ja antaa lähtökohdan tulevalle mobiilien vertaisverkon sisällönjakelujärjestelmien kvantitatiiviselle mallinnukselle. Systeemidynamiikka on toteuttamiskelpoinen vaihtoehto tavallisemmille mallinnustekniikoille, kuten taulukkolaskentamallinnukselle, jonka etuna on järjestelmän takaisinkytkentäsilmukkojen mallintaminen. Kun mobiili vertaisverkkoteknologia kehittyy, enemmän dataa tulee saataville ja vaihtoehtoisten systeemidynamiikkamallien rakentaminen on suositeltavaa.The success of peer-to-peer technology in the fixed networks has led to peer-to-peer implementations in the mobile networks as well. There is, however, a lot of uncertainty regarding the future of mobile peer-to-peer technology as the operators and other stakeholders that were affected negatively by illegal peer-to-peer file sharing in the fixed networks are afraid that it might happen in the mobile domain as well. Thus they might try to prevent mobile peer-to-peer technology from emerging. There is also the question whether there really is a need for peer-to-peer technology in the mobile domain from the end users' perspective, especially as the mobile device capabilities are considerably lower compared to the fixed ones. This thesis concentrates on mobile peer-to-peer content distribution. Content distribution is divided to file exchange, content streaming and commercial content systems. The thesis provides insight to the most relevant scenarios, stakeholders and their incentives related to mobile peer-to-peer content distribution. The uncertainty regarding mobile peer-to-peer content distribution will be bounded using scenario analysis and modeled using system dynamics. The most relevant scenarios regarding mobile peer-to-peer content distribution are constructed using Schoemaker's method and modeling of these scenarios is attempted with system dynamics. As a result four different scenarios are developed based on the key trends and uncertainties discovered during the literature review and brainstorming sessions. Instead of modeling the scenarios quantitatively, the dynamic behavior of a mobile peer-to-peer content distribution system based on the scenarios is modeled with system dynamics. Although there are some mobile peer-to-peer content distribution applications already developed and used, and the topic is considerably researched, it is still uncertain what the outcome of the technology will be. This thesis presents possible outcomes for the technology and provides a starting point for further quantitative modeling of mobile peer-to-peer content distribution systems. System dynamics provides a viable alternative to more common modeling techniques such as spreadsheet modeling, with a distinctive benefit of modeling the feedback loops in a system when used proficiently. As the mobile peer-to-peer technology evolves, more data becomes available and the construction of alternative system dynamics models is encouraged

Mobile Service Substitution on Modern Smartphones: Case Facebook

Social media services, including Facebook, have recently grown to be a substantial part of everyday communication for hundreds of millions of people. Mobile technology has evolved to a point where a modern smartphone can be constantly connected to the Internet, facilitating straightforward communication via mobile social media services. This can introduce service substitution, where users communicate through these services instead of mobile operator provided calling or SMS services. In this article, we have studied Finnish Facebook users and their mobile Facebook usage with quantitative methods. Based on a review of the existing research, seven hypotheses are proposed of which six have statistical differences when comparing modern smartphones and older phones. Using this comparison, the results include evidence of Facebook mobile being a substitute to the traditional calling and text message services, as well as the importance of push notifications. Based on the results, further research areas are proposed. Keywords: Social media services; Mobile application usage; Service substitutio

Handset-Based Data Collection Process and Participant Attitudes

Julkaisun kokoteksti on luettavissa vain Aalto-tunnuksilla.Please note that access to the fulltext is limited to Aalto staff and students.Handset-based measurements are an emerging method for collecting behavioral data about smartphone users. Setting up these kinds of measurements is challenging because of the personal nature of the data collection device and a lack of standards related to behavioral data and the method as a whole. Privacy issues related to the participants of the data collection are of major importance when dealing with behavioral data. Introduced is the process of collecting handset-based data in the OtaSizzle project in the Aalto University community in Finland together with a literature review of other similar data collection efforts in academia and industry. A survey is also deployed to study the incentives for participation, privacy concern levels and innovativeness of the user group participating in the measurements. This article contributes to the body of knowledge regarding measurements conducted with smartphones and sheds light on participant attitudes about them.Peer reviewe

Mobiilien ihmistenvälisten viestintäpalveluiden käytön empiirinen analyysi

The ways in which people communicate and keep in touch with each other are changing. Our relationships are shaped by the wide variety of communication possibilities available, and the overall increase in mediated communication. On the other hand, the relationships also shape the use of different means of communication. Since the proliferation of mobile phones, mobile voice calls and SMSs have become the world’s most ubiquitous form of mediated communication. More recently also newer mobile communication services have emerged, which are not necessarily provided by mobile operators, but based on the Internet instead. The merger of the mobile and Internet domains is further accelerating the changes in how we socialize. The purpose of this thesis is to empirically analyze the use of mobile interpersonal communication services by using a quantitatively driven mixed method design, with handset-based measurements as the core data collection method. The aim is to fill in the research gap of sparse objective user-level research on mobile communication service usage. Handset-based measurements enable collecting actual mobile phone usage data from users who have opted in to participate and install a research application to their devices. Because of the personal and social “always on” nature of the data collection device, we are able to collect rich location-based and context-sensitive data about how mobile communication services are used. The main data analyzed are collected from up to 200 participants from a longitudinal research panel with a span of more than a year. In addition to handset-based measurements, surveys and semi-structured interviews are used as complementary methods. In this thesis mobile communication services are found to be used differently based on a number of factors. Mobile phone use context and the strength of the tie between the persons communicating are the most salient ones. For example, SMSs are used more with strong ties when compared to voice calls. Moreover, the lengthiest and the briefest voice calls are made in the Home and Office contexts, respectively. Consequently, the usage interrelationships of mobile communication services are discussed from a mobile operator perspective. The use of multiple and dynamic datasets in social network analysis is also encouraged, as the analysis of different communication channels may or may not lead to different views of the social network under analysis. Thus, the thesis and the results of the research can be valuable for practitioners and academics in the area of mobile ecosystems, particularly mobile operators. The thesis also contributes to the emerging fields of communication and social network research, namely computational social science and social computing.Tavat, joilla ihmiset viestivät ja pitävät yhteyttä toisiinsa ovat muuttumassa. Ihmissuhteisiimme vaikuttaa viestintämahdollisuuksien laaja kirjo, sekä yleinen välitteisen viestinnän lisääntyminen. Toisaalta ihmissuhteemme muokkaavat myös sitä, kuinka eri viestintätapoja käytämme. Matkapuhelinten lisääntymisen myötä matkapuheluista ja tekstiviesteistä on tullut maailman käytetyin välitteisen viestinnän muoto. Lisäksi viime aikoina on ilmestynyt uusia mobiileja viestintäpalveluita, jotka eivät välttämättä ole mobiilioperaattoreiden tarjoamia, vaan Internet-pohjaisia. Mobiili- ja Internet-alojen yhteensulautuminen kiihdyttää muutoksia viestinnässämme entisestään. Tämän väitöskirjan tarkoitus on empiirisesti analysoida mobiilien viestintäpalveluiden käyttöä. Pääasiallisena tutkimusmenetelmänä käytetään kvantitatiivisia päätelaitepohjaisia mittauksia. Tutkimuksen tavoitteena on tuottaa lisää tietoa mobiilien viestintäpalveluiden käytön objektiivisista käyttäjätason tutkimuksista. Päätelaitepohjaiset tutkimukset mahdollistavat todellisen käyttötiedon keräämisen matkapuhelinten käyttäjiltä, jotka ovat päättäneet osallistua tutkimukseen ja asentavat tutkimussovelluksen matkapuhelimiinsa. Matkapuhelin soveltuu erittäin hyvin mobiilien viestintäpalveluiden käytön tutkimiseen henkilökohtaisena, sosiaalisena ja aina päällä pidettävänä laitteena, koska sen avulla voidaan kerätä rikasta, paikkakohtaista ja kontekstiherkkää tietoa. Analysoitava pääaineisto on kerätty jopa kahdensadan osallistujan pitkittäisestä, yli vuoden kestävästä, paneelitutkimuksesta vuosien 2009 ja 2010 aikana. Päätelaitepohjaisten mittausten lisäksi kyselytutkimuksia ja puolistrukturoituja haastatteluita käytetään täydentävinä tutkimusmenetelminä. Tässä väitöskirjassa on havaittu mobiilien viestintäpalveluiden käytön riippuvan monesta eri tekijästä. Matkapuhelimen käyttökonteksti (esim. aika ja paikka) ja viestivien henkilöiden välisen suhteen vahvuus ovat näistä keskeisimmät. Tekstiviestejä käytetään esimerkiksi enemmän vahvojen suhteiden kanssa, kuin matkapuheluita. Toisaalta pisimmät matkapuhelut tehdään kodin tyyppisissä, ja lyhimmät toimiston tyyppisissä konteksteissa. Väitöskirjassa pohditaan myös mobiilien viestintäpalveluiden käytön välisiä riippuvuussuhteita mobiilioperaattorin näkökulmasta. Lisäksi tutkimus kehottaa käyttämään useita aikasarjaan perustuvia aineistoja sosiaalisten verkostojen analyysissä, koska eri viestintäkanavien analyysi voi johtaa erilaisiin näkökulmiin analysoitavasta sosiaalisesta verkostosta. Täten väitöskirja ja sen tulokset voivat olla erityisen arvokkaita mobiilioperaattoreiden alalla toimiville ammatinharjoittajille ja akateemikoille. Väitöskirja edistää myös viestinnän ja sosiaalisten verkostojen tutkimuksen uusimpia aloja, kuten laskennallista yhteiskuntatiedettä

Mobile social phonebooks - Mobile phone user perceptions and practical implications for mobile operators

Julkaisun kokoteksti on luettavissa vain Aalto-tunnuksilla.Please note that access to the fulltext is limited to Aalto staff and students.We introduce a term called mobile social phonebook, which refers to the integration of traditional mobile phone contacts with contacts from mobile Internet communication services that is happening in the mobile device’s phonebook. First, mobile phone user perceptions towards mobile social phonebooks are studied by means of semi-structured interviews. The results of the interviews are combined with related work and discussed from a mobile operator perspective. We claim that mobile social phonebooks will have an effect on the interrelationships of mobile communication services and discuss implications related to providers, privacy and future of mobile social phonebooks. Moreover, we claim that the future analysis on interrelationships needs to happen on a more detailed level, than what has been achieved so far. This paper contributes to the research fields of mobile platforms and mobile communication services and is valuable both for practitioners and academics.Peer reviewe

Building social capital with mobile communication services

Julkaisun kokoteksti on luettavissa vain Aalto-tunnuksilla.Please note that access to the fulltext is limited to Aalto staff and students.People may use different kinds of mobile communication servicesdepending on if they are communicating with, for instance, friends,acquaintances or strangers. Thus, in this paper bonding and bridging socialcapital is studied in the context of two mobile communication services, shortmessage services (SMSs) and voice calls. In Granovetter’s terms, bridgingsocial capital refers to communication with weak or absent ties, while bondingsocial capital refers to communication with strong ties. We find that both SMSsand voice calls are used for bonding and bridging social capital, but SMSs areused more for bonding purposes than voice calls. Furthermore, mediamultiplexity is more associated with bonding than bridging social capital.We also present a method for studying social capital in the context of other,newer mobile communication services, and present results of a pilot study.The implications of the results are discussed from a number of perspectivesincluding communication research, social network analysis (SNA) and mobileoperators.Peer reviewe

Measuring social relations with multiple datasets

Julkaisun kokoteksti on luettavissa vain Aalto-tunnuksilla.Please note that access to the fulltext is limited to Aalto staff and students.Because people have different levels of engagement with each other,measuring social relations is difficult. In this work, we propose a methodof measuring social relations with multiple datasets and demonstrate thedifferences with empirical evidence. Our empirical findings demonstrate thatpeople use different communication media channels differently. Therefore, wesuggest that in order to understand social structures, one should use severalkinds of data sources and not just depend on a single dataset. Our datasetsinclude mobile phone data gathered with handset-based measurements and datafrom OtaSizzle online social media services. By means of social networkanalysis, we show that the online social media services have a differentfriendship network than the networks based on mobile phone communication.The mobile phone communication networks, however, have a very similarstructure. These results are encouraging as previous research also indicatesdifferences in the communication networks.Peer reviewe

Measuring Social Relations: Case OtaSizzle

Julkaisun kokoteksti on luettavissa vain Aalto-tunnuksilla.Please note that access to the fulltext is limited to Aalto staff and students.There are different levels of engagement in socialrelations between persons. Using a single data set for measuringsocial relations may, however, lead to fallacious results, whileusing multiple data sets the threat of fallacy can be reduced andthe nature of different kind of social relations examined. Thispaper presents the OtaSizzle research platform for combiningmultiple data sets and measuring social relations. To present theusefulness of this, the first empirical results of the social networkanalysis performed with the platform are presented anddiscussed. Handset-based measurements are used together withdata from the OtaSizzle social media services to study the socialrelations within a group of 20 users. As a result the socialnetworks derived with the different data sources are presentedand compared and a number of future research items discussed.According to the measures calculated the social networks derivedfrom the mobile devices are quite similar while the OtaSizzleservice network is considerably different, indicating a differencein the online social network and the communication networkinside the user group.Peer reviewe

Substitution in smartphone communication services

Julkaisun kokoteksti on luettavissa vain Aalto-tunnuksilla.Please note that access to the fulltext is limited to Aalto staff and students.Substitution between mobile internet communication services and traditional mobile operator-provided communication services is studied in this paper using smartphones. The empirical data are collected with handset-based measurements conducted in Finland between 2008 and 2010. The data are collected from a total of 183 early adopter Symbian smartphone users. The individual-level correlation analysis indicates that no clear evidence in favor of substitution can be found. This implies that the services are used for different purposes as independent services and are not direct substitutes to each other. The results support similar studies conducted by other researchers. However, the analysis can be extended and improved in a number of ways that are discussed as future research.Peer reviewe