A Generalized Architecture for Bookmark and Replay Techniques Thesis Proposal By Napassaporn Likhitsajjakul

Outline Background Problem statements Objective Methodology Plan

BACKGROUND

Today’s Information system Information system is used to capture key information. - Analysis component is the most important part since it will be used for decision making process or illustration Merit of information system is that, given some amount of data, it should yield meaningful analysis results.

Today’s Information system Information analysis is “iterative” in nature But conventional systems mostly focus on the final artifacts of analysis (e.g. report) - Static, lack of exploratory characteristics - Relevant information during the analysis process is lost while it is useful

Why relevant information during analysis process is important? Exploratory Data Analysis (Tukey, 1977) - Not only focus on dataset, but also the exploration process used to produce the results Analysis process is iterative (Goldstein et al, 1994) - Analysts usually navigate back and forth to a point in time - But mostly today’s interfaces does not support that since it just focuses on one state at a time

Bookmark and Replay State Analysis activities can be done in effective and efficient ways by keeping the history of exploration and analysis process along with reporting artifacts - Freely navigate to an interested point in time - No need to start over from the beginning - Reusability of analysis context State must be saved in some way that can be reconstruct later

Bookmark and Replay State Bookmark and replay concept can be very easy in some static applications - e.g. Website bookmarking in a web browser Can be very difficult in dynamic application - e.g. Simulation (results at every second, have to run the whole simulation again) But it is possible in User Interface and Analysis - e.g. Statistical analysis, GIS application

Bookmark and Replay State There are 2 main approaches currently used in applications: BookmarkReplay Copying State Save the snapshot of whole state Restore the milestone snapshot of state Command pattern Ensure actions have corresponding “compensation action” that nullify effects Record sequence of command to reach the desired state Issue the compensation actions of recorded command to the current state Issue recorded command to the initial state

PROBLEM STATEMENTS

Problem #1 Data exploration process is left behind after provided output artifacts. - Analysts cannot backtrack /navigate to the interested point that has previously explored - Exploration process cannot be reused - Limits the efficiency and effectiveness of analysis

Problem #2 The currently used method for bookmark and replay introduced a lot of overhead in execution time and memory usage. - Copying State:  Overhead in saving and restoring state - Command sequence:  Overhead in restoring state  Not possible for every commands  Difficult to design and implement

OBJECTIVES

Objective To develop an architecture to support navigation to a point in the history of analysis in dynamic application - Design and implement two alternative To analyze and evaluate resource required for typical interaction pattern in real case study for the alternatives - Effectiveness, limitation - Optimization, improvement

Objective (cont.) To generalize the architecture for applying to other dynamic applications - Develop a set of architectural patterns for different application domains

Scope and Limitation Focus on 2 alternatives for history navigation: state copying and command patterns Focus on GIS application (SavGIS) as an example of dynamic application Extend to support navigation to the history of analysis

RELATED WORKS

Time Travel Interface Extension of Visage software Backtracking and investigating alternative scenarios - Record history of events and modeled them as a tree - Decouple actions from states of application (Derthick & Roth, 2001) Drag the slider to go back to the history

Temporal model for undo/redo Record command history during a session Command history is modeled as a directed graph in temporal order Undo/redo by invoke/reverse operations Difficult to apply command object pattern (Flatland application) - Effects of operation must be known in advance to enable undo - Difficulty in design and implementation Linear timeline (Edward et al., 2000)

METHODOLOGY

Overview

Methodology Step 1 Select alternative to be analyzed - Start with “Command pattern” - Followed by “State copying” after finished Step 3 Step 2 Modify application to support alternative - Implement an extension to coordinate states, history of commands, and images snapshot of state Linkage between screenshots and history of commands Navigability between states in history Command pattern Navigability between states in history State copying

Methodology (cont.) Step 3 Analyze alternative with a case study - Resource requirement - Interaction pattern - Limitation - Potential for improvement (optimization)

Methodology (cont.) Step 4 Generalize the architecture - Classify application domains - Develop a set of architectural pattern for different application domains

PLAN

August Semester TasksAugSepOctNov Select alternative: Command pattern Study alternatives Modify application to support “command pattern” Study SavGIS software Implement extensions Analyze “command pattern” with case study Collect case study Analyze system

January Semester TasksJanFebMarApr Select alternative: State copying Study alternatives Modify application to support “state copying” Study SavGIS software Implement extensions Analyze “state copying” with case study Analyze system Generalize architecture

References Edwards, W. K., T. Igarashi, et al. (2000). A temporal model for multi- level undo and redo. Proceedings of the 13th annual ACM symposium on User interface software and technology. San Diego, California, United States, ACM. Derthick, M. and S. F. Roth (2001). "Enhancing data exploration with a branching history of user operations." Knowledge-Based Systems 14(1-2): Souris, M. (29 June 2010). "SavGIS - Geographical Information System ". Retrieved 28 September, 2010, from Unger, B. W., J. G. Cleary, et al. (1993). An external state management system for optimistic parallel simulation. Proceedings of the 25th conference on Winter simulation. Los Angeles, California, United States, ACM.

Q & A

Comments Change “dynamic apps” to “EDA apps” Iteration = 1 month (implement, analyze) Analyze 2 method [copy state + macro]at the same time - Look for more alternative (combination of state copy + command) This semester 2 iterative with about 3 case study Focus more on analysis not implementation - How state is bookmark? Database? Make it like Visage State in SavGIS = content of map not interface