The information visualizer, an information workspace

Stuart K. Card et al
[ACM Link]

This contained descriptions of an "information workspace" called Information Visualizer, that combined elements of 3D Rooms (organizing work into sets of items), a Cognitive Co-processor (increase speed and usefulness/validity of user searches), and information visualization (options such as hierarchical structires, linear structures, and data sculptures).

Information retrieval is usually part of another task from the users' point-of-view, so it should be integrated with those tasks and not difficult. Info retrieval always has a cost - it can best be balanced if a small amount of frequently or recently used info is kept in an Immediate Storage area, while voluminous, less-used info is kept in higher-cost, larger-capacity Secondary Storage. It is also possible to have Tertiary Storage farther away.

Organizational aspects of information retrieval

• Hierarchy - organization improves processing cost
• High Cost Ratios - Cost of info retrieval varies depending on how difficult it was to find and/or assimilate
• Locality of Reference - Information tends to be used in clusters, not spread evenly through all storage
• Reference Clustering - Information usage tends to jump from cluster to cluster rather than slowing moving around throughout all storage
• Max Info/Cost - Systems tend to get as much info as possible based on cost constraints
• Abstraction - Higher levels of organization can be abstracted

A workspace is a solution for immediate storage needs, and multiple, switchable workspaces tend to be even better, except for the time/cost involved in switching.

A General-Purpose File System For Secondary Storage

R.C. Daley, P.G. Neumann
[Link]

This paper was primarily focused on shared file systems. It contained some basic explanations of file systems, but wasn't particularly HCI oriented. It indicated that often users have difficulty with file systems because of lack of (or hidden) information about the file, such as who can access it or how. Another contributing factor to user confusion is hierarchies that are too many levels deep. Symbolic links can aid in ease-of-use, because the user's work to find the file and they don't have to know the actual pathname. The rest of the paper was not relevant. It continued by describing read, execute, write, and append privileges, methods for backups and recovery, and system processes for accessing file segments and page tables.

Going beyond the hierarchical file system: A New Approach to Document Storage and Retrieval

Manuel Arriaga
[Link]

This paper discusses the limitations and problems of Hierarchical File Systems (HFS). Though it started as a translation of real-world office filing with papers in folders, the metaphor could be expanded and enhanced with computers.

It is a weakness that files can only be store in one place - this causes users to need the whole pathname to get the context of the file, and sometimes makes it difficult to locate documents using a different sorting method than was originally planned for the hierarchy.

This author recommends a "Newdocms" plan which allows users to "store document metadata as (attribute,value) pairs". The plan takes into account parent/child relationships in categories, so that a search for "animal" documents would also retrieve documents categorized as being about "cats" and "dogs". Users can still save files as uncategorized, but have the option to save attributes with the file for more accurate searches.

Visualising File-Systems Using ENCCON Model

Quang V. Nguyen, Mao L. Huang
[Link]

Very helpful and concise paper which outlines the 4 types of interfaces that have been used to represent hierarchical file systems

• Listings: command line (dir or ls) - Simple and detailed, but difficult to understand and use
• Outlines: windows explorer types - Easy to understand, but fails with deep hierarchies
• Connection: Node-link diagrams - Best for seeing file relationships, but not efficient with screen space
• Enclosure: Files are represented as appropriately-sized rectangles within parent rectangles - Efficient with space, but more difficult to understand file relationships

The authors propose an enclosure + connection approach (ENCCON) that is efficient with screen space and shows clear relationships between files. This involves keeping geometric partitions from enclosure as well as lines between files to show relationships. Semantic zooming with animation is recommended to show detailed close-ups of individual files.

Hierarchy

In Pursuit of Desktop Evolution: User Problems and Practices With Modern Desktop Systems

PAMELA RAVASIO, SISSEL GUTTORMSEN SCHA¨ R, and HELMUT KRUEGER
[ACM DL]

• the basic underlying tasks to be accomplished during the organization of personal information can be divided into the acts of information handling, categorization, filing, and retrieval.
• the act of classification was accompanied by a major cognitive load, which users tried to defer as long as possible.
• some pieces of information fit into more than just a single category. Several subjects identified a solution to that problem, namely to store the same piece of information in various places. However, none of them chose to pursue that solution.
• subjects preferred spatial classification over logical classification, and that retrieval by numerous attributes was more natural to them than by a single attribute.
• there exist two fundamentally different types of filing: neatly defined, classified files and folders; and complimentary piles, which were an attempt to manage information quickly and informally.
• people with low spatial ability have orientation problems and are thereby disadvantaged when using hierarchical file systems.
• ordering strategies were similar in the virtual office and in the physical office.
• people use three kinds of information: ephemeral, working, and archived.
• three problematic points:

(1) Lack of a facility for the support of temporary file configuration; (2) lack of user support to track down and plan personal activities; and (3) the inability of the system’Äôs file information to recreate its context.

The Memory Extender Personal Filing System

William Jones
[ACM DL]

• The user of predominantly name-oriented approach of most current filing systems experiences problems of both recall and recognition.
• The single-name representations of a computer-based filing system stand in stark contrast to the richly indexed representations of human memory.This leads to an impoverishment in the language of the human/computer dialogue.
• A file is reprsented, i.e. indexed, in the ME system by a set of variably weighted, bi-directional term links.

Keeping Found Things Found on the Web

William Jones, Harry Bruce, Susan Dumais
[ACM DL]
Worth reading. Does a good job at sumarising the problems in organising files, emails and Web Info. Cites a number of papers on file hierarchy and related areas.

• people tend to organize the papers in their offices into ’Äúpiles’Äù and tiles. Piles are located spatially around the office and serve as a kind of short-term memory. In particular, piles often provide a reminding function.
• people have increasing difficulty keeping track of the contents of different piles as their number increases.
• a rapid falloff in the ability of people to retrieve information by location cues alone as the number of information items increased beyond ten.
• Memory for names was much less subject to disruption as the total number of items increased
• ’Äúlocation-based’Äù finding. The user first guessed which folder a desired file was in. The user then generated a listing of files in this folder and attempted to recognize the desired

file in this listing.

• Users preferred not to enter the tile name directly nor did they typically

search on the tile name.

• filing decisions - which folders to create, what to name them,

how to organize them, etc. - are fundamentally difficult regardless of the item being filed.

• Folders were sometimes much too large or too small (containing only one or two items) to have organizing value.
• ’Äúout of sight, out of mind’Äù problem that items placed in a

folder were sometimes forgotten until well after the period of their usefulness had passed.

• Bookmarks are a widely used web feature. However few users in their study chose to re-name bookmarks.
• Maintaining a hierarchy of folders takes effort. If not maintained, the hierarchy can quickly get out of date.

The Task Gallery: a 3D window manager

George Robertson
[ACM Link]

This useful paper states that a virtual art gallery-like desktop (Task Gallery) can help with task management, is enjoyable, adn evokes spatial memory and cognition. When designing for file management, the following should be considered: creating, locating, bringing tasks into focus, window management within a task.

The Task Gallery has open windows for tasks on the walls, floor, and ceiling. When a task is clicked, it moves to the center stage area. Frequently used files are kept in a start palette in the virtual "left hand".

An experiment with space-filling windows which resize automatically to fill the screen was a failure because it confused users.

3D space for documents has been shown to help users remember where their documents are. Animation should be used for reinforcement. An art gallery was chosen because it is a familiar metaphor. The space of a linear hallway is helpful to non-gamers who are not accustomed to navigation in 3D.

In the Task Gallery, a task can be composed of multiple windows which are organized in a stack on a podium. The The user may change view, or use "glancing" - "a lightweight, ephemeral way of looking around in a virtual environment without moving the virtual body."

Studies on the Task Gallery have shown that

• Users prefer placement of objects on walls rather than ceilings and floors
• They had no trouble recognizing the art gallery hall as a 3D space
• They could remember most of the order and locations of tasks/files even after they were away from the prototype
• Landmarks would be helpful in future prototypes