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Trade-offs between Quality and Efficiency in Multilingual Dense Retrieval / Avvägningar mellan kvalitet och effektivitet i f lerspråkig tät informationssökningSchüldt, Emma January 2022 (has links)
As the amount of content online grows, information retrieval becomes increasingly crucial. Traditional information retrieval does not take the text order into account and is also dependent on exact text matching between the query and the document. Therefore, a query consisting of synonyms to words in a document will not retrieve that document even if it could have been relevant to the user. An alternative approach is dense retrieval which solves these issues by representing the semantic meaning of the query or document using a vector representation. Semantically similar queries and documents are represented with vectors close to each other in a vector space. Vector similarity search can be used to find the most relevant documents for a query. Since the semantic meanings of the words are used, synonyms and paraphrases are handled implicitly. There are several ways to design these representation vectors, either by using one or several vectors to represent each query or document, by changing the dimensionality of the vectors, or by changing the span of values in the vectors. Each option brings its trade-offs in terms of quality of search results, query latency, and index memory footprint. This study experimented with each of the alternatives above. Since most previous research within the area has been done in a monolingual, mainly English context, this study used four different languages to investigate if the trade-offs differed. In this study, the quality, latency, and memory footprint moved in the same direction, i.e., when the quality increased, then the latency increased as well. This was the case for all the languages. For the version that used one vector each for the document and query, decreasing the dimensionality to 128 or 64 gave significant latency improvements but did not affect the quality. For the larger version, which used 32 vectors for the query and 64 for the document, converting the values of vectors to binary had no significant effect on quality but greatly reduced the storage size. / Mängden innehåll på internet växer, och med det behovet av välfungerande informationssökningssystem. Traditionella sökmotorer tar inte hänsyn till ordföljden och är beroende av exakt textmatchning mellan sökfrågan och dokumentet. På grund av detta kommer en sökfråga som innehåller synonymer till ord i ett dokument inte att hämta det dokumentet, även om det hade kunnat vara relevant för användaren. En annan metod är tät informationssökning (en: Dense Retrieval) som löser de här problemen implicit genom att representera den semantiska betydelsen av sökfrågan eller dokumentet med en vektorrepresentation. Semantiskt lika sökfrågor och dokument representeras av närliggande vektorer i ett vektorrum. Likhetssökning med vektorerna kan användas för att hitta de mest relevanta dokumenten för en sökfråga. Eftersom ordens semantiska betydelse används, hanteras synonymer och parafraser implicit. Det finns flera sätt att utforma vektorerna, antingen genom att använda en eller flera vektorer för att representera varje sökfråga eller dokument, genom att ändra vektorernas dimensionalitet, eller genom att ändra spannet för vektorernas värden. Varje alternativ har sina egna för- och nackdelar med avseende på sökresultatens kvalitet, sökningarnas tidsåtgång, och hur mycket minne indexet upptar. I den här studien har vi undersökt alla ovanstående aspekter. Eftersom den mesta tidigare forskningen enbart har gjorts i en engelsk kontext, använder den här studien fyra olika språk för att se om föroch nackdelarna skiljde sig åt mellan de olika språken. I den här studien rörde sig kvaliteten, söktiden och minnesavtrycket i samma riktning, det vill säga när kvaliteten ökade, ökade också söktiden. Detta gällde för alla olika språk. För versionen som använde en vektor vardera för sökfrågan och dokumentet, gav en minskning av dimensionaliteten till 128 eller 64 betydande minskningar av söktiden men förändrade inte kvaliteten. För den större version som använde 32 vektorer för sökfrågan och 64 för dokumentet, gjorde inte en omvandling av vektorernas värden till binära någon skillnad för kvaliteten, men minskade lagringsutrymmet betydligt.
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Begagnade bilar : Konsumentens val mellan privatköp och den etablerade bilhandelnTholin, Amanda, Hagström, Johanna January 2008 (has links)
<p>Begagnade bilar köps och säljs i allt högre utsträckning mellan privatpersoner, något som drabbar bilhandlare genom en för dem minskad försäljning. Syftet med denna uppsats är att undersöka hur privatpersoner väljer var de ska köpa begagnad bil. Vi vill utforska hur de söker efter information om bilar, samt vilka faktorer som påverkar valet av inköpsställe. En kvantitativ enkätundersökning har utförts bland privatpersoner som köpt begagnad bil och resultaten av denna undersökning visar att priset på bilen är den mest avgörande faktorn vid val av inköpsställe. I slutsatsen kan även konstateras att Internet är det ledande informationssökningsredskapet innan köp av bil.</p>
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Informationssökning bland nyblivna mödrar : En deskriptiv tvärsnittsstudieNyberg Eiroff, Gunilla, Frank, Kiro January 2014 (has links)
Bakgrund: Graviditet och tidigt moderskap är perioder då kvinnor aktivt söker ny kunskap. Tillgången till hälsorelaterad information är enorm men kvaliteten på innehållet varierar mellan olika källor. För att kunna göra informerade val i hälsofrågor behöver mödrar evidensbaserad information, och det är en barnmorskas ansvar att kunna guida dem till högkvalitativa källor. Syfte: Syftet med denna studie var att kartlägga nyblivna mödrars informationssökning samt att undersöka om det finns samband mellan informationssökning och olika sociodemografiska bakgrundsvariabler. Metod: Undersökningen baserades på delar av en pilotstudie inför ett större europeiskt projekt och data från 137 enkäter till nyblivna mödrar analyserades. Resultat: De mest använda informationskällorna bland mödrarna var barnavårdscentral och vårdsidor på Internet, således källor som tillhandahåller evidensbaserad information. Nästan lika populärt var dock att vända sig till familj och vänner och till Internetforum, där kvaliteten på informationen kan variera och ibland skapa missförstånd och oro. Slutsats: Barnmorskor bör därför hålla sig uppdaterade på det informationsflöde som finns, känna till vilka informationskällor deras patienter använder och vilken typ av information de hämtar. De bör också kunna guida sina patienter till högkvalitativ information. / Background: Pregnancy and early motherhood are periods when women are actively seeking new knowledge. The public access to health information is enormous but the quality of the content varies between different sources. To make informed health choices, mothers need evidence-based information, and midwives have a responsibility to guide them to highqualitative sources. Aim: The aim of this study was to explore new mothers’ information seeking and to investigate the relationship between information seeking and various sociodemographic background variables. Method: The study was based on parts of a pilot study prior to a wider European project, and data from 137 questionnaires to new mothers were analysed. Results: The most frequently used sources of information among the mothers were childcare centres and health sites on the Internet, thus sources that provide evidence-based information. Almost as popular was, however, to turn to family / friends and to Internet forums, where the quality of information can vary and sometimes create confusion and anxiety. Conclusion: Midwives should therefore stay updated on the predominant flow of information, know which sources of information their patients are using and what type of information they obtain. They should also be able to guide their patients to high-quality information.
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Informationssökning och källkritik på Internet : En studie om lärares uppfattning av innehållet i läroplanen för årskurs 4-6, om informationssökning och källkritik på Internet samt lärares upplevelser av dessa i undervisningen / Information retrieval and source criticism on the InternetGamaleldin, Selma January 2016 (has links)
Inom ämnena svenska och samhällskunskap ska det ske undervisning i informationssökning och källkritik i olika medier i grundskolan. Syftet med denna studie är att bidra med information om hur lärare i årskurs 4-6 uppfattar informationssökning och källkritik i läroplanen samt hur lärare upplever undervisningen i dessa. Enligt den redovisade forskningen i denna studie är källkritik en del av informationssökningen och att lärare anser att elever i årskurs 4-6 inte ska undervisas i informationssökning och källkritik på Internet samt att det finns flera olika sätt för lärare att bedriva sin undervisning. Studien har en kvalitativ fenomenografisk och fenomenologisk forskningsansats. Materialet samlades in genom intervjuer och analyserades genom en kartläggning på likheter och skillnader samt genom att se mönster i lärarnas utsagor. Resultatet visar att lärarna anser att källkritik och informationssökning i undervisningen inte går att särskiljas från varandra, att lärare i årskurs 4-6 bör undervisa elever i informationssökning och källkritik på Internet och att lärare använder sig av diverse olika sätt att bedriva sin undervisning på. / Within the subjects of Swedish and Civics there must be teaching in information retrieval and source criticism in various media in primary school. The purpose of this study is to provide information on how teachers in grades 4-6 perceive information retrieval and source criticism in the primary school curriculum and how teachers experience teaching this subject. According to the research reported in this study the source criticism is part of the information retrieval and that teachers believe that students in grades 4-6 should not be taught information retrieval and source criticism on the Internet, and also that there are several different ways for teachers to pursue their teaching. The study has a qualitative phenomenographic and phenomenological approach. The materials were collected through interviews and was analyzed by mapping the similarities and differences and by finding patterns in the teachers´ descriptions. The results show that teachers believe that the criticism of sources and information retrieval in the teaching can not be distinguished from eachother, that the teachers in grades 4-6 should teach students in information retrieval and source criticism on the Internet and that teachers use various ways to conduct their teaching.
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Miljömedvetenhet på Seychellerna : en studie om invånarnas egna uppfattning angående tillgänglighet av information om miljöproblem / Environmental awareness in Seychelles : study of the inhabitants' self-assessed awareness and perceptions regarding availability of information on environmental issuesAspenfelt, Emelie, Pettersson, Rebecka January 2015 (has links)
This study is a result of a participation in the Minor Field Study program where we interviewed inhabitants in Mahé, Seychelles, about environmental awareness and information sources and/or channels. Seychelles has a distinguished environment to preserve and protect for the sake of both human and nature and public awareness plays an important part in upholding this. Our aim with this thesis is to study the inhabitants' self-assessed awareness and perceptions regarding availability of information on environmental issues in Seychelles. Furthermore we hope that a by-product of our study will be an addition to the ongoing discussion and knowledge development regarding the global environmental and climate issues. Seven semi-structured interviews were conducted and T. D. Wilson's information behaviour model from 1996 was used as theoretical framework when analysing the material. The results show a varied range of self-assessed awareness and perceptions regarding environmental issues and the availability of relevant information and information sources and/or channels.
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Högskolebibliotekariers informationssökning : en studie i hur högskolebibliotekarier söker information till sig själva och för andra / The information seeking of academic librarians : a study of how academic librarians seek information for themselves and for othersGunnarsson, Ted, Persson, Emma January 2007 (has links)
The purpose of this thesis is to examine how academic librarians seek information for themselves and for others, and what differences exist. The terms self-generated and imposed information seeking is used to describe the two different types of information seeking. Step 2 – define and understand the problem, step 3 – choose a search system and step 4 – formulate a query of Marchionini’s information-seeking model forms the basis of the theoretical framework, which is supplemented with Soergel and Katz. Qualitative interviews with eight academic librarians were conducted and analyzed in order to gather empirical facts. The results show that the greatest differences between self-generated and imposed information seeking lie within the definition and understanding of the information problem. The library user’s information need is specified through the reference interview; a process often seen as somewhat problematic by the librarians because of the difficulties involved in trying to understand another person’s needs. Librarians tend to approach imposed information seeking in a structured and pedagogic manner because of their desire to instruct the library user in the use of various databases and search techniques. The Internet is the most used information source during self-generated information seeking, while the library catalogue is the primary source during imposed information seeking. The results also show that only small differences exist in the way librarians use search strategies and search tactics during the two different types of information seeking. / <p>Uppsatsen skrevs under den tid då Växjö universitet hade ett samarbete med Högskolan i Borås, dvs. utbildningen gick i Växjö, men Borås examinerade.</p>
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Bibliotekariers och universitetslärares syn på informationskompetens / Librarians´ and University Teachers´ View on Information LiteracyLutmark, Daniel January 2014 (has links)
The purpose of this thesis was to investigate on what perspective or perspectives university teachers and librarians at a medium-sized university in Sweden base their view on information literacy. More specifically, how do the respondents view their own information literacy and what opinions they have of their students’ information literacy as professionals. Three perspectives are used to interpret the results, the sociocultural perspective, the phenomenographical perspective and the behavioristic perspective.The method used is semi structured interviews with three university teachers and three librarians.Both librarians and teachers emphasize the importance of information literacy, for themselves as well as for students. The information literacy of the librarians involves being well acquainted with the subjects of the students. The teachers mention their ability to guide students in their search for sources and literature.Librarians consider the information literacy of students pretty poor or very poor, and one respondent says that more experienced students often have greater knowledge. The teachers agree that there are differences between more and less experienced students, but both positive and negative exceptions occur. Both librarians and teachers consider information literacy among students as important, because it is important to find relevant information to essays and papers. The three perspectives are connected or not connected to answers that the three librarians and the three teachers reply in interviews. This is important for how they do re-search, talk about and teach information literacy. / Program: Bibliotekarie
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Förmedling av discovery-verktyg vid högskole- och universitetsbibliotek : En enkätstudie om undervisande bibliotekariers inställningar till discovery-verktyg och hur de förmedlar dessa vid referenssamtal och användarundervisning / Mediating discovery tools in higher education libraries : A survey of instructing librarians' attitudes towards discovery tools and how they mediate these through reference interviews and user trainingHannerz, Einar, Wiborgh, Mika January 2014 (has links)
The purpose of this thesis is to examine how Swedish highereducation librarians mediate discovery tools to its users. Thisstudy aims to investigate higher education librarians’ generalattitudes towards discovery tools, their perception ofstudents’ discovery tool usage, and how they mediatediscovery tools to students through reference interviews anduser training. The empirical ground of this study is a semistructuredsurvey that was answered by 115 instructinglibrarians. The study concludes that although librariansgenerally have a critical attitude towards discovery tools theyalso think that the discovery tools serve a useful purpose,especially as a starting point in the information searchprocess. The study also concludes that librarians generallyperceive students’ attitudes towards discovery tools aspositive, although students do not always use the tools totheir full potential. The librarians also raised the importanceof user training that is less focused on teaching searchtechniques and more focused on information literacy. / Program: Bibliotekarie
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Mobila enheter som stöd i informationssökning och hantering inom yrkesutbildning : Aspekter av kommunikation, samarbete och lärande / Mobile Device Supported Information Searching and Management in Vocational Education The aspects of Communication, Collaboration and LearningTammi, Minna January 2014 (has links)
The purpose of this thesis is to outline experiences of mobile devices’ suitability to using them in teaching from teacher’s perspective inside Finnish vocational schools; how to benefit devices better in learning process, communication, collaboration, information searching and sharing between teacher, student, stakeholders and outer world. Mobile learning as an extension and possibility to more regenerative learning, effective communication and information management tool is viewed from working life demands in the 21st century. The core my study consists of information and communications technology (ICT) literacy skill, which is the ability to use technology to develop 21st century content knowledge and skills, in the context of learning core subjects and further in the working life. / Program: Magisterutbildning i strategisk information och kommunikation
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Neutrala verktyg för ovinklade fakta eller onda, partiska profitörer? En undersökning och jämförelse av tre webbsöktjänsters träfflistor. / Neutral tools for unbiased information or evil, greedy manipulators? An evaluation and comparison of search results by three web-based search engines.Göransson, Karl, Helge, Jon January 2006 (has links)
The purpose of this thesis is to evaluate three web-based search engines and compare the 10 first retrieved documents. We used the search engines Google, Yahoo! and Exalead. The evaluation is based upon 20 topics with strong polarized opinions and these have been derived from Swedish media and every day life. From these topics we have constructed the 20 queries used for searching. The 10 first documents are each placed in four different categories, For, Against, Neutral or Irrelevant. For and Against are opposed to each other regarding different opinions in the 20 topics. The purpose of this is to get a picture of the different topics, seen through the three search engines. Does one of the categories weigh more heavily than the other, represented in the 10 first documents? If this is the case, does the same category weigh more heavily in all three search engines, or how do they deviate from each other? The results showed that one of the categories, in most of the topics, weighs more heavily than the opposed category. The opposed category is in some cases not represented at all in the 10 first documents. In some of the topics, the same category weighs over in all three search engines, but in more than half of the topics the different search engines deviate from each other regarding the opposed categories. / Uppsatsnivå: D
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