The influence of electronic word of mouth (eWOM) on consumers’ purchase intentions has long been known. However, the emergence of social media has brought a new perspective to eWOM through enabling users to communicate with their existing networks on the Internet. On social media, conversely to the other online platforms, users are able to exchange their opinions and experiences about products or services with familiar people, which refers to people who they already know such as friends and acquaintances. This new way of eWOM has the potential for greater impact on consumers. Therefore, the aim of this research is to examine the influence of eWOM in social media on consumers’ purchase intentions. To do so, the research in this thesis involved two major phases. In the first phase, in order to explore the determinants of eWOM information on social media which influences consumers’ purchase intentions, a theoretical model was developed based on the integration of Information Adoption Model (IAM) and related components of Theory of Reasoned Action (TRA). The new model, which is named as Information Acceptance Model (IACM), was validated through structural equation modelling (SEM) based on surveys of 384 social media users in the UK. The results have highlighted that quality, credibility, usefulness and adoption of information, needs of information and attitude towards information are the key factors for eWOM in social media which influence consumers’ purchase intentions. Furthermore, to provide better understanding of the influence of eWOM on social media, the second phase of this research was designed as a comparative study. To explore whether the eWOM between familiar people on social media or the eWOM between anonymous people on other online platforms was more influential on consumers’ purchase intentions, the data collected through survey was reanalysed with a different perspective; and a comparison was conducted based on multiple regression analysis. The results have revealed significant differences and found anonymous reviews to be more influential on consumers’ purchase intentions than friends’ recommendations on social media. However, since these results were contrary to expectations, 10 in-depth interviews were also administered to enlighten the insightful results found through the survey. The interview findings uncovered the survey results. Information quantity, information readiness, detailed information, and dedicated information were discovered as the factors which make online reviews superior than friends’ recommendations in terms of the influence of eWOM. This research contributes to theoretical implications through its validated model and found key dimensions. The research model, IACM, brings a new approach to information adoption by extending IAM and provides new insights to researchers who study Information Systems (IS). In addition, the model highlights the information adoption process as an antecedent of behavioural intention, which is a very important finding for the related literature. Future studies can build new models through considering this relationship between information adoption process and behavioural intention. Moreover, the second phase of this research provides new constructs for future studies through its qualitative findings. The findings reached through in-depth interviews, which explain why consumers prefer anonymous online reviews, can either be tested as components of new theories and models or they can be tested as inclusion of existing theories and models. Both types have potential to provide valuable results for the literature. On the other hand, in terms of practicality, this research provides marketers with a frame of reference to understand the influence of eWOM in social media on consumers’ purchase intentions. Both the contextual and the comparative studies in this research offer valuable insights for marketers; marketers thus can develop better strategies for marketing on social media.

Vid ett e-handelsköp finns det två alternativ för informationssamling om produkten som skall köpas, produktinformation från e-handlaren och kundomdömen från tidigare konsumenter. Postnords e-barometer har flera år visat att svenska konsumenter önskade att e-handlare utvecklade kundomdömen på sina plattformar vilket denna studie har intresserat sig för att undersöka. Arbetet är av kvantitativ karaktär och har som syfte att undersöka svenska konsumenters användning av kundomdömen inför ett köp och vilka faktorer som påverkar användningen. För detta används en teoretisk modell med tillhörande hypoteser som är en förläning på TAM-modellen. Undersökningen bestod av en surveyundersökning där enkät har använts som datainsamlingsmetod. Resultatet visar på att de flesta respondenter till underökningen är positivt inställda till kundomdömen. De tycker att det är användbart, användarvänligt, betydelsefullt och har även en avsikt att använda dem innan köp. Dock är det väldigt få som använder omdömessystemet efter köp för att dela med sig av sina åsikter eller på annat sätt använda omdömessystemet. Studien föreslår att svenska konsumenter är mycket mer tystlåtna när det gäller eWOM än var tidigare studier har visat. Kundomdömen upplevs inte som trovärdiga, vilket dock inte visade sig vara en faktor som har en påverkan på användandet av kundomdömen vid köp. De faktorer som visade sig ha en stark direkt påverkan på avsikten att använda kundomdömen vid ett köp är omdömessystemets användbarhet och betydelse. En indirekt påverkan visade det sig att användarvänligheten har vilket påverkar användbarheten. Detta resultat skiljer sig från den ursprungliga TAM-modellen som menar att även användarvänligheten direkt påverkar avsikten att använda. Vidare har det i studien även identifierats olika demografiska grupper med olika datorvanor vilket har en medelmåttig effekt på hur användarvänligt ett omdömessystem upplevs. Resultaten visar också att det finns statistisk signifikanta skillnader mellan demografiska grupper och deras förhållning till kundomdömen. Kvinnor har en mer positiv syn på omdömessystem och har dessutom ett större förtroende till dem än män. Vidare upplever de kunder som ofta eller aldrig returnerar varor efter ett köp att kundomdömen är mer betydelsefulla och användbara. / When purchasing online there are two alternatives to collect information about the product of interest, product information from the e-retailer and customer reviews from previous customers. Postnord’s e-barometer has several years shown that Swedish customers wish that e-commerce providers developed customer reviews on their platforms, which are the main topic for this study. This work is of a quantitative nature and aims to explore Swedish online customers use of customer reviews before making a purchase and factors that influence their use. For this, a theoretical model with associated hypotheses has been used which is an extension on the original TAM-model. The study is a survey study where a survey was used as a primary data collection to test the model and analyze about factors that influence each other. The result of this study shows that most of the study’s respondents have a positive attitude towards customer reviews, they believe it is useful, easy to use, important and have intentions to use it before a purchase online. However, very few respondents tend to use customer review systems after purchases to share their purchase experience or use it in other ways. The study proposes that Swedish customers are much more of a silent observer when it comes to eWOM than what previous studies have found. Customer reviews is not perceived to be trustworthy, which however this study shows is not a factor that influence the intention to use customer reviews, in other words, customer reviews are perceived useful even if they are not trustworthy. The factors that proved to have strong direct influence on the intention to use customer reviews is the usefulness of the customer reviews system and the perceived importance of it. Additionally, the ease of use has an indirect influence, which differs from the original TAM-model which means that the ease of use directly influences the intention to use. Furthermore, different demographic groups with different computer experience has been identified, which has a moderate effect on the perceived ease of use customer reviews systems. The result also shows that there are statistically significant differences between demographical groups, and their relation to customer reviews. Women has a more positive view of customer reviews and perceive them to be more trustworthy than men. Furthermore, customers with different product return behaviors has different perceptions of the importance of customer review systems and the ones who never or often return products after a purchase online tend to perceive customer reviews more important.

El objetivo de esta investigación es analizar como las reseñas en el social media afectan al valor de marca de los hoteles 5 estrellas en el distrito de Miraflores de la ciudad de Lima. El estudio inicia con la investigación en fuentes con la finalidad de definir los conceptos de: social media, reseñas online, turismo, conocimiento de marca, imagen de marca y lealtad de marca; además de conocer el contexto actual del sector hotelero. Después, se enmarca en una investigación que utiliza una metodología mixta (cualitativa y cuantitativa) con un alcance exploratorio y correlacionar. En la fase cualitativa, se realizan entrevistas a profundidad y estructuradas a expertos digitales del social media y branding. Asimismo, usuarios representantes del servicio hotelero. Finalmente, en la fase cuantitativa se aplica un cuestionario a una muestra de 282 personas hospedajes en los 9 hoteles de cinco estrellas de Miraflores. Se obtiene como resultado que efectivamente las reseñas positivas o negativas afectan al valor de marca de los hoteles. Por ello, a mayor experiencia del cliente con las plataformas donde el consumidor participa y crea contenido, esta influirá en sus actitudes hacia valor de marca de los hoteles. Además, influye tanto en su decisión de compra como selección del hotel, dependiendo de las calificaciones anteriores en dichas plataformas. Finalmente, se proponen acciones para los gerentes de los hoteles. / The objective of this research is to analyze how the reviews in the social media affect the brand value of the five stars hotels in the Miraflores district of the city of Lima. The study begins with research in sources with the purpose of defining the concepts of: social media, online reviews, tourism, brand awareness, brand image and brand loyalty; besides knowing the current context of the hotel sector. Later, it is part of a research that uses a mixed methodology (qualitative and quantitative) with an exploratory and correlational scope. In the qualitative phase, in-depth and structured interviews are conducted with digital experts of social media and branding. Also, users representing the hotel service. Finally, in the quantitative phase a questionnaire is applied to a sample of 282 people staying at the 9 five-star hotels in Miraflores. The result is that effectively positive or negative reviews affect the brand value of the hotels. Therefore, the greater the customer experience with the platforms where the consumer participates and creates content, this will influence their attitudes towards the brand value of the hotels. In addition, it influences both your purchase decision and hotel selection, depending on the previous ratings on those platforms. Finally, actions are proposed for hotel managers. / Trabajo de investigación

Ensuring the objectivity of systematic reviews and meta-analyses (SRMA) begins with comprehensive searches into diverse resources mining primary studies. Guidelines for systematic reviews recommend authors to routinely search of trial registries to identify unpublished studies. In this dissertation, I investigated the utilization of ClinicalTrials.gov (CTG), the world’s largest clinical trial registry that contains data from clinical trials of products that are subject to United States Food and Drug Administration (FDA) regulation, as an information resource in SRMAs. First, I examined the use of various information resources including CTG in SRMAs published from 2005-2016, and identified the factors associated with their use. Thereafter, to determine the accuracy of trial safety data reported at CTG, I compared the data at CTG with that in corresponding journal articles and FDA drug reviews. I found that trial safety data at both CTG and articles differed frequently from FDA drug reviews, but the differences were modest in magnitude. Finally, I repeated published meta-analysis (conducted using data from primary study articles) with data at CTG to find that most meta-analysis results were reproduced using CTG data. Taken together, this work suggests that CTG should not only be searched more often to find primary research for systematic reviews, but that data at CTG can also be used to conduct quantitative data synthesis.

Indiana University-Purdue University Indianapolis (IUPUI) / The internet is the home for massive volumes of valuable data constantly being created, making it difficult for users to find information relevant to them. In recent times, online users have been relying on the recommendations made by websites to narrow down the options. Online reviews have also become an increasingly important factor in the final choice of a customer. Unfortunately, attackers have found ways to manipulate both reviews and recommendations to mislead users. A Recommendation System is a special type of information filtering system adapted by online vendors to provide suggestions to their customers based on their requirements. Collaborative filtering is one of the most widely used recommendation systems; unfortunately, it is prone to shilling/profile injection attacks. Such attacks alter the recommendation process to promote or demote a particular product. On the other hand, many spammers write deceptive reviews to change the credibility of a product/service. This work aims to address these issues by treating the review manipulation and shilling attack scenarios independently. For the shilling attacks, we build an efficient Reinforcement Learning-based shilling attack method. This method reduces the uncertainty associated with the item selection process and finds the most optimal items to enhance attack reach while treating the recommender system as a black box. Such practical online attacks open new avenues for research in building more robust recommender systems. When it comes to review manipulations, we introduce a method to use a deep structure embedding approach that preserves highly nonlinear structural information and the dynamic aspects of user reviews to identify and cluster the spam users. It is worth mentioning that, in the experiment with real datasets, our method captures about 92\% of all spam reviewers using an unsupervised learning approach.

Titel: Kan jag lita på dig? – En studie om hur demografiska faktorer påverkar förtroendet till Electronic Word of Mouth inom försäljningsbranschen. Nivå: C-uppsats, examensarbete i företagsekonomi Författare: Jonatan Viklund & Robert Sundström Handledare: Jonas Molin & Lars-Johan Åge Datum: 2019-09-07 Syfte: Syftet med studien är att analysera hur förtroendet till eWOM inom försäljningsbranschen påverkas av demografiska aspekter. Metod: Studien använder en kvantitativ forskningsmetod bestående av en survey-undersökning som behandlade 25 frågor inom demografi samt recensioner knutna till fastighetsmäklare. Totalt samlade undersökningen in svar från 100 respondenter varav 93 från dessa kunde användas. Därefter analyserades de insamlade svaren i SPSS där deskriptiv-, korrelations- samt klusteranalys genomfördes. Resultat och slutsats: Resultatet av studien visar att det existerar både skillnader och likheter gällande förtroende i direkt korrelation till demografiska skiljaktigheter. Två av studiens fyra hypoteser verifierades och en verifierades delvis vilket besvarade syftet att förtroende till eWOM skiljer sig mellan demografiska grupper. I regel läser majoriteten av konsumenterna recensioner, yngre generationer upplever ett större förtroende till eWOM och kön eller utbildning har ingen direkt koppling. Uppsatsens bidrag: Studien bidrar till ökad förståelse för hur demografi påverkar förtroendeskapande, i detta fall specificerat till försäljningsbranschen. Studien bekräftar och dementerar även tidigare forskning inom konsumentbeteende och demografiska frågeställningar samt öppnar upp för vidare forskning. Förslag till vidare forskning: Vidare forskning bör fortsätta i våra fotspår men kan göras på högre nivå med större kvantitet av respondenter som återspeglar samhället bättre. Även mer specificerad forskning till individuella demografiska faktorer och även flera faktorers samband till förtroende behövs. Nyckelord: Förtroende, demografi, eWOM, recensioner, försäljning, fastighetsmäklare / Title: Can I trust you? - A study on how demographic factors affect trust in Electronic Word of Mouth in the sales industry Level: Final assignment for a bachelor’s degree in business administration Author: Jonatan Viklund & Robert Sundström Supervisor: Jonas Molin & Lars-Johan Åge Date: 2019-09-07 Aim: The aim of the study is to analyze how trust in eWOM in the sales industry is affected by demographic aspects. Method: The study uses a quantitative research method consisting of a survey which dealt with 25 issues in demography and reviews related to real estate agents. In total, the survey collected responses from 100 respondents where 93 of these could be used. Subsequently, the collected responses were analyzed in SPSS where descriptive, correlation and cluster analysis were performed. Results and conclusion: The results of the study show that there are both differences and similarities in trust in direct correlation to demographic differences. two of the study's four hypotheses were verified alongside one partially verified, which answered the purpose that trust in eWOM differs between demographic groups. As a rule, consumers read reviews, younger generations experience greater trust, and gender or education has no direct link. Contribution: The study contributes to an increased understanding of how demography affects trust, in this case specified to reviews in the sales industry. The study also confirms and denies previous research in consumer behavior and demographic issues. Further Research: Further research should continue in our footsteps but be done at a higher level with respondents who reflect society better. Even more specific research is needed for individual demographic factors and a group of factors correlation with trust. Keywords: Trust, demography, eWOM, reviews, sales, real estate agents

"The purpose of this study, then, is to determine whether or not the monthly selections of The Literary Guild of America are of good enough quality to enable the library staff to accept them as really good choices of current fiction. This paper includes a brief sketch of the history of the Literary Guild which outlines the club's background and selection and distribution policies. Next it presents an examination of each of the twelve titles distributed to Guild members in 1948, followed by a summary of the findings. An annotated bibliography of the titles selected by the Guild in 1947, arranged in order of issuance to members, is appended to this paper"--Introduction. / Typescript. / "August, 1953." / "Submitted to the Graduate Council of Florida State University in partial fulfillment of the requirements for the degree of Master of Science." / Advisor: Mary Edna Anders, Professor Directing Paper. / Includes bibliographical references (leaves 53-58).

This study examines the effect of electronic Word-of-Mouth (eWOM) on consumers’ purchasing decision process, more specifically: How does consumer attitudes and purchasing intent toward companies and their products affected by negative eWOM on social media. The study is based on three-component model of attitudes which identifies attitude as the awareness, assessment and readiness to act. The purpose of this study was to examine how negative eWOM on social media affects the consumer’s purchasing decision process. The purpose was to improve understanding of eWOM’s role and influence on the consumer’s attitudes and purchasing intent towards the companies and their products.   The authors conducted semi-structured interviews with 13 individuals aged 18-20. Results indicate that negative customer reviews on social media have a negative influence on consumers attitudes and purchasing intent. The results also show that the effect varies between different product types. The effect may be stronger for expensive and important purchases than for cheap and routine purchases.

Sentiment classification is the process of categorizing data into categories based on its polarity with a wide array of applications across several industries. This report examines a combination of two prominent approaches to sentiment classification using a lexicon of weighted words and machine learning respectively. These approaches are compared with the combined hybrid approach in order to give an account of their relative strengths and weaknesses. When run on a set of IMDb movie reviews the results indicate that the hybrid model performs better than the lexicon-based approach, in turn being outperformed by the learning-based approach. However, the gain in convenience brought on by eliminating the need for training data makes the hybrid model an appealing alternative to the other approaches with a slight trade-off in performance. / Att klassificera text i kategorier baserat på känslan de uttrycker är ett aktuellt område idag och kan tillämpas inom många industrier. Rapporten undersöker en kombination av de två framstående tillvägagångssätten till denna typ av klassificering baserade på ett lexikon med definerade ordvikter respektive maskininlärning. Denna hybridlösning jämförs mot de två andra tillvägagångssätten för att framlägga deras relativa styrkor och svagheter. På ett dataset med filmrecensioner från IMDb får maskininlärningsklassificeraren bäst resultat, följt av hybridlösningen och sist den lexikonbaserade lösningen. Trots det kan hybridlösningen vara att föredra i situationer där det är ogenomförbart eller oskäligt att förbereda träningsdata för maskininlärningsklassificeraren, dock med ett visst avkall på prestanda.

Systematic Literature Reviews (SLR) are a powerful research tool to identify and select literature to answer a certain question. However, an approach to extract inherent analytical data in Systematic Literature Reviews’ multi-dimensional datasets was lacking. Previous Systematic Literature Review tools do not incorporate the capability of providing said analytical insight. Therefore, this thesis aims to provide a useful approach comprehending various algorithms and data treatment techniques to provide the user with analytical insight on their data that is not evident in the bare execution of a Systematic Literature Review. For this goal, a literature review has been conducted to find the most relevant techniques to extract data from multi-dimensional data sets and the aforementioned approach has been tested on a survey regarding Self-Adaptive Systems (SAS) using a web-application. As a result, we find out what are the most adequate techniques to incorporate into the approach this thesis will provide.