Transcript Document
Models for Digital Libraries CSC 9010 - week 2 The 5S model is the work of Edward A. Fox and his students at Virginia Tech. These slides rely heavily on that work. Week 2 goals • Discuss reading of “As we may think” • Review of points in the discussion of What is a Digital Library? • Introduce a formal model of digital libraries • Use the 5 S model to direct thinking about the design of a DL • Briefly introduce systems to be used Our systems • 7 linux machines, remotely accessible • Bare machines with just basic system • We will install apache and the rest of the web infrastructure, as well as the DL software. • Detailed instructions will be available next week. memex • Vannevar Bush’s vision – How far have we come? – What did you notice about this article -- style or content or background or anything else. – Did the article suggest anything you would not want to see happen? Image source: kelty.rice.edu/375/images/memex/camera.jpg http://www.knowledgesearch.org/presentations/etcon/images/memex.gif MyLifeBits • Gordon Bell and Microsoft • http://www.guardian.co.uk/science/story/0,3605,1674359,00.html “Gordon Bell doesn't need to remember, but has no chance of forgetting. At the age of 71, he is recording as much of his life as modern technology will allow, storing it all on a vast database: a digital facsimile of a life lived. If he goes for a walk, a miniature camera that dangles from his neck snaps pictures every minute or so, immediately committing the scene to a memory built not of neurons but ones and noughts. If he wanders into a cafe, sensors note the change in light, the shift of temperature and squirrel the information away. Conversations are recorded and steps logged thanks to a GPS receiver carried with him.” Related work • Walden’s Path – http://www.csdl.tamu.edu/walden/ – System used by itself or as a service within a digital library – Allows a user to make a path through a set of related resources and save the path for reuse at a later time. • Used to allow a teacher to “blaze a trail” through a collection of materials to help students find their way from a starting point to a goal. • Also for recording personal trips through a collection of material to be revisited. Moving Forward • Last week – Looked at what a library is • Now – How do we translate that to a digital entity? • Information resources, including digital libraries, are very complex systems. – A formal model helps to capture the essence of the system and give special attention to specific areas – The model also allows developers of digital libraries to have a check list of areas to consider and develop well. The 5S model • Streams – The flow of information in various formats • Structures – Organizational aspects of the DL • Spaces – Views of components; real or abstract images • Scenarios – Services and behaviors • Societies – Communities and relationships among them 5S summary Model Primitives Formalisms Objectives Stream Text; video, audio, software program Sequences, types Describes properties of the DL content, encoding and textual material or particular forms of multimedia data. Structure Collection, catalog; hypertext; document; metadata; organizational tools Graphs; nodes; links; labels; hierarchies Specifies organizational aspects of the DL content Space User Interface; index; retrieval model Sets; operations; vector Defines logical and space; measure space; presentational views of several probability space DL components Scenarios Service, event; condition; action Sequence diagrams; collaboration diagrams Details the behavior of DL services Societies Community; managers; actors; classes; relationships; attributes; operators Object-oriented modeling constructs; design patterns Defines managers responsible for running DL services; actors that use those services, and relationships among them Source: http://www.dlib.vt.edu/projects/5S-Model/ Etana - A DL for archeology An example application of 5S Etana: A DL for an archeological site Scenario model Society model Archaeologist General public Services Value added Service Manager Domain specific Space model Geographic space Structure model Region Stream model User interface Text *Partition Video Information Satisfaction Metric space Metadata *Site Repository building *Sub-partition Audio Taxonomies Spatial Temporal Artifact-specific *Locus Drawing *Container Photo *Artifact 3D Source: E. A. Fox http://feathers.dlib.vt.edu/ Case study: Subjects of interest for creating a DL: • • • • __6__ History of ___ • _9__ Graduate _14__ Personal Photos programs - computing __6__Computing Topic • _6__ Wildlife __9__ Poems, essays • _6__ Pets or other literature • _2__ Gardening • __9__ Cars, trucks • _3__ Course syllabi • _18__ Movies, TV • _5__ Other: ___ programs, or other media 2 most popular - personal photos and movies, etc. Use these as a working example. Applying the model, informally Personal Photos; Movie, TV, media • Stream - what types of data? Gif, jpg, avi? • Structure - How are the elements organized? Is there a hierarchy? Are there multiple structures? • Spaces - How will we index the items? How will we divide them into related groups • Scenarios - what services will we provide? What information do we need to provide those services? • Societies - who is the library intended to serve? Remember to include agents and other processes as well as users. In your group, choose one or the other. Start with stream, scenarios, societies. More formally: Definitions • Definition: A stream is a sequence whose co-domain is a non empty set. • Definition: A structure is a tuple (G, L, F) where G = (V,E) is a directed graph with vertex set V and edge set E, L is a set of label values, and F is a labeling function. Definitions, cont’d • Definition: A space is a measurable space, measure space, probability space, vector space, topological space, or metric space – A vector space is a representation for the set of elements in a collection. The vector representing each element is a set of characteristics held by that element and both connecting that element to others that are similar and distinguishing it from those that are different. – We will do an exercise to illustrate Definitions - 3 • Definition: A scenario is a sequence of related transition events (e1, e2, …, en) on state set S such that ek = (sk, sk+1,) for 1 <= k <= n. – More easily visualized, a scenario is a path in a directed graph, G = (S, ∑e), where vertices correspond to states in the state set S and directed edges are equivalent to events in a set of events, ∑e, and correspond to transitions between states. – Scenarios must be implemented to make a working system. Definitions - 4 • Definition: A society is a tuple (C,R) where – C = (c1, c2, …, cn) is a set of conceptual communities, each community referring to a set of individuals of the same class or type (e.g. actors, activities, components, hardware, software, data); – R = (r1, r2, …, rm) is a set of relationships, each relationship being a tuple rj = (ej, ij) where ej is a Cartesian product ck1 x ck2 x … x cknj. 1<= k1 < k2 < … < knj<= n, which specifies the communities involved in the relationship and ij is an activity. Summary - Week 2 • Continued to explore what a digital library really is • Introduced some formal concepts for modeling a DL • Briefly discussed the installation and operation of our own DLs.