Visualization By: Simon Luangsisombath

Canonical Visualization  Architectural modeling notations are ways to organize information  Canonical notation – every notation has at least one visualization that is directly and specifically associated with it  A common pitfall is to associate an architecture modeling notation as only with canonical notation or view a notation and its canonical notation as the same thing  Notation is a way organizing abstract information  Visualization dictates how information is depicted and interacted with  Visuals are not optimal for all uses so notations which there exists multiple visualizations are generally preferred than single canonical visualizations

Textual Visualizations  They depict architectures using text files  Generally conform to a particular syntactic format such as.java or.c  Several advantages  Depict entirety of an architecture in a particular notation in a single file  Many technologies have been researched for parsing, processing and editing structure text  When a textual syntax is defined many tools are available to generate library's that can parse and check syntax of text documents in that language  Disadvantage  It is not understood well with graph like structures  Text editors are limited to showing a screen full of text with few options of organization

Textual depictions for an architecture in xADL and xADLite.

Graphical Visualizations  Depicted as architectures using graphical symbols  Generally conform to a syntax but my also be free form  They give stakeholders access to information about architecture that text does not  Symbols, colors and other visual decorations can easily be distinguished  They can use special relationships to express relationships among elements  Disadvantage  Cost of building tools to support them  More popular tools lack understanding of architectural semantics and is difficult or impossible to add appropriate semantics and interactions to a wider software engineering environment

Hybrid Visualizations  Many visualizations blur between graphical and textual  Some can be composites of many different visualizations  EX: UML composite structure diagram is primarily graphical visualization used to contain other UML diagrams  Composite visualizations can be good for displaying relationships between different aspects of the same architecture  But they can be quickly become complex and confusing as depictions and interaction mechanisms are combined  Strategies such as drill down interaction can mitigate complexity

Relationship between Visualization and views  Effective use of view and viewpoints help consider different subsets of design decisions in an architecture  Visualization for a viewpoint defines depiction and interaction mechanisms only for the kinds of design decisions included in viewpoint  Associate visualization with viewpoints rather than views  A visualization can be used to visualize many architectures

Various UML diagram types.

Evaluating Visualizations  Fidelity is a measure of how faithfully a visualization represents a underlying model  Consistency is a measure of how well a visualization uses similar depictions and interaction mechanism for similar concepts  Comprehensibility is a measure of how easy it is for stakeholders to understand and use a visualization  Dynamism is a measure of how well a visualization supports models that change over time  View coordination is how well one visualization is coordinated with others  Aesthetics is a measure of how pleasing a visualization is to its users  Extensibility is a measure of how easy it is to modify a visualization to take on new capabilities, for either depiction or interaction

Constructing a Visualization  Borrowing Elements from Similar Visualizations  Be Consistent among Visualizations  Give Meaning to Each Visual Aspect of Elements  Document the Meaning of Visualization  Balance Traditional and Innovative Interfaces

Coordinating Visualizations  It is key that visualizations must coordinate with each other  Four general synchronization strategies  Peer to Peer  Visualization maintain their own copies of information, know about each other explicitly and notify change  This strategy is more suitable for small fixed number of visualizations chosen in advance  Master-slave  One Visualization is responsible for interacting with the model repository and serves as master  This works when one visualization is auxiliary to another  Pull-Based  Each Visualization repeatedly queries a shared model for changes and updates itself  Pull based strategies can be used when the model repository is entirely passive  The disadvantage is it may display out of date information until it performs a pull  Pushed based  Visualizations are notified and consequently update themselves whenever model changes

Multiple strategies for coordinating visualizations of the same information: (a) peer-to-peer, (b) master-slave, (c) pull, and (d) push.

Beyond Design: Using Visualization dynamically  Effective visualization is a visualization that does not represent architectural design decisions directly, but instead represents effect of architectural design decisions

Figure 7-7. Visualization combining elements from xADL and UML. Generating effect visualizations.