An Optimal Trade-off between Content Freshness and Refresh Cost

Caching is an effective mechanism for reducing bandwidth usage and alleviating server load. However, the use of caching entails a compromise between content freshness and refresh cost. An excessive refresh allows a high degree of content freshness at a greater cost of system resource. Conversely, a deficient refresh inhibits content freshness but saves the cost of resource usages. To address the freshness-cost problem, we formulate the refresh scheduling problem with a generic cost model and use this cost model to determine an optimal refresh frequency that gives the best tradeoff between refresh cost and content freshness. We prove the existence and uniqueness of an optimal refresh frequency under the assumptions that the arrival of content update is Poisson and the age-related cost monotonically increases with decreasing freshness. In addition, we provide an analytic comparison of system performance under fixed refresh scheduling and random refresh scheduling, showing that with the same average refresh frequency two refresh schedulings are mathematically equivalent in terms of the long-run average cost

An Overview of Sakai 3

Sakai 3 will eventually mean a major change in IU's Oncourse. This talk will provide an overview of Sakai 3 current plans and directions. A demo will illustrate some of the major changes coming in Sakai, including a new emphasis on content authoring and social media. There will also be an opportunity to discuss the implications of Sakai 3 for libraries

A stochastic model for the evolution of the web allowing link deletion

Recently several authors have proposed stochastic evolutionary models for the growth of the web graph and other networks that give rise to power-law distributions. These models are based on the notion of preferential attachment leading to the ``rich get richer'' phenomenon. We present a generalisation of the basic model by allowing deletion of individual links and show that it also gives rise to a power-law distribution. We derive the mean-field equations for this stochastic model and show that by examining a snapshot of the distribution at the steady state of the model, we are able to tell whether any link deletion has taken place and estimate the link deletion probability. Our model enables us to gain some insight into the distribution of inlinks in the web graph, in particular it suggests a power-law exponent of approximately 2.15 rather than the widely published exponent of 2.1

Charles B. Notess Papers - Accession 265

Dr. Charles B. Notess (1928-2008) was a professor of Sociology at Winthrop College from 1975 to 1981. The Charles B. Notess Papers consist of bylaws, organizational records, correspondence, news releases, membership lists, newspaper clippings, and other material relating to the Concerned Citizens for Rural Recreation, York County Rural Development Commission, York County Recreation Study Committee, and a conference held at Winthrop College in 1980 titled “Dialogue on Human Values Guiding Regional Growth.” Also included are lecture notes, examinations, and syllabi from his courses.https://digitalcommons.winthrop.edu/manuscriptcollection_findingaids/1265/thumbnail.jp

Studying Digital Library Use

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Variations2: Moving Beyond Access to Pedagogy

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The Library User Experience: Why it matters and how it can be improved

User Experience (UX) encompasses not just usability but a customer’s total experience of products, services, and organizations. This talk focuses on the technology-mediated experience people have with the Libraries. I begin by explaining the key concepts of UX and give some examples of why it matters to us. I will describe a range of UX methods for improving UX and will talk about how those methods can be applied to technology-based products and services in the Libraries. I will also summarize the charter of the new UX consulting group in the Bloomington Libraries and describe we can assist with UX improvements. Although this talk will focus on libraries, most of it will apply to any technology-based project

An Assessment of Contextual Design and Its Applicability to the Design of Educational Technologies

Thesis (PhD) - Indiana University, School of Education, 2008Increased use of computing technology in support of learning necessitates the collaboration of instructional designers with technology designers. Yet the instructional designer portrayed in current instructional design textbooks does not participate in technology design but instead designs instructional strategies and materials that are implemented by others. For instructional systems design as a field to move towards the kinds of collaborative work required for the development of effective, innovative educational technologies, there is a need for methods that can integrate the concerns and activities of both instructional and technology designers. This research critically examines a human-computer interaction design method, contextual design (CD), assessing how practitioners employ and characterize it as a method and explores its potential utility in instructional systems design. CD is briefly described and available evaluative studies are summarized. Next, three studies are presented: a case study of CD usage in the design of a digital music library, a case study of CD integrating with another design approach called PRInCiPleS, and a learning-oriented analysis of CD work models. Based on the findings of the literature review and these three studies, a practitioner survey and interview guide were developed. Results from 106 survey respondents and 16 interviews characterized CD as a guiding framework and a collection of useful techniques. However, because of its resource requirements and other limitations, the method is rarely used in full or exclusively. Respondents reported valuing the ability of CD to uncover and communicate user needs but also suggested CD did not provide a means of resolving conflicts between user needs and organizational objectives. Implications of these results are explored for three constituencies: developer-designers of instructional places or interactive materials, educators of instructional designers who will work with software developers, and educational researchers and their graduate students

Variations: Building a Digital Music Library Community

Over the past 15 years, Indiana University has been a leader in the development of digital library systems for music through a series of projects collectively known as Variations. Most recently, the Variations3 project, funded in part by a National Leadership Grant from the Institute of Museum and Library Services, supported the release of the Variations digital music library system as open source software, freely available for use by other institutions. The Variations system is in production use at seven colleges and universities beyond IU, with approximately ten others actively piloting the system. In this talk, we will summarize the results of the Variations3 project's development and evaluation activities, discuss some of the successes in and challenges to adoption by other institutions, and discuss potential future directions for the project

Listening and Normative Entanglement: A Pragmatic Foundation for Conversational Ethics

People care very much about being listened to. In everyday talk, we make moral-sounding judgements of people as listeners: praising a doctor who listens well even if she does not have a ready solution, or blaming a boss who does not listen even if the employee manages to get her situation addressed. In this sense, listening is a normative behaviour: that is, we ought to be good listeners. Whilst several disciplines have addressed the normative importance of interpersonal listening—particularly in sociology, psychology, media and culture studies—analytic philosophy does not have a framework for dealing with listening as a normative interpersonal behaviour. Listening usually gets reduced mere speech-parsing (in philosophy of language), or into a matter of belief and trust in the testimony of credible knowers (in social epistemology). My preliminary task is to analyse why this reductive view is taken for granted in the discipline; to diagnose the problem behind the reduction and propose a more useful alternative approach. The central task of my work is to give an account of listening which captures its distinctively normative quality as an interpersonal way of relating to someone: one listens not because the speaker is an epistemic expert, but because the speaker is a person, worthy of recognition and care. I created a framework which accomplishes this by deploying the conceptual resources of conversation sociology and psycholinguistics, in counterpoint to the standing philosophical work on the ethics and politics of speech and silencing, to create a practical ethics of listening to people