Today's widely deployed painting applications use a linear undo model that allows users to backtrack previous operations in reverse chronological order. This undo model is not useful if the user has performed desired operations after undesired ones. Selective undo, in contrast, allows users to select specific operations in the past and only undo those, while keeping the remaining operations intact. Although selective undo has been widely explored in the context of text editing and object-oriented drawing, we explore selective undo for painting (bitmap) editing, which has received less attention and introduces many interesting user interface design challenges. Our system, called Aquamarine, explores the script model for selective undo, where selectively undone operations are skipped in the history, rather than the more explored inverse model, which puts an inverse of the selected operations at the end of the history. We discuss the design implications and show through two informal user studies that selective undo is usable and desirable

RADAR is a multiagent system with a mixed-initiative user interface designed to help office workers cope with email overload. RADAR agents observe experts to learn models of their strategies and then use the models to assist other people who are working on similar tasks. The agents' assistance helps a person to transition from the normal email-centric workflow to a more efficient task-centric workflow. The Email Classifier learns to identify tasks contained within emails and then inspects new emails for similar tasks. A novel task-management user interface displays the found tasks in a to-do list, which has integrated support for performing the tasks. The Multitask Coordination Assistant learns a model of the order in which experts perform tasks and then suggests a schedule to other people who are working on similar tasks. A novel Progress Bar displays the suggested schedule of incomplete tasks as well as the completed tasks. A large evaluation demonstrated that novice users confronted with an email overload test performed significantly better (a 37% better overall score with a factor of four fewer errors) when assisted by the RADAR agents.

In the past decade there has been spectacular growth in the number and size of third-party libraries, frameworks, toolkits and other Application Programming Interfaces (APIs) available to modern software developers. However, the time-saving advantages of code re-use are commonly hampered by the difficulty in finding the correct methods for a given task among the thousands of irrelevant ones. We have developed a tool called Apatite that helps address this issue by letting programmers browse APIs by viewing associations between their components. Apatite indicates which items of an API are popular in different contexts and allows browsing by initially selecting verbs (methods and actions) in addition to classes and packages. The associations are calculated by leveraging existing search engine data and source code, and verbs are identified by parsing the documentation descriptions. Apatite is available on the web and is being used by developers worldwide on a regular basis.

Calcite is a new Eclipse plugin that helps address the difficulty of understanding and correctly using an API. Calcite finds the most popular ways to instantiate a given class or interface by using code examples. To allow the users to easily add these object instantiations to their code, Calcite adds items to the popup completion menu that will insert the appropriate code into the user's program. Calcite also uses crowd sourcing to add to the menu instructions in the form of comments that help the user perform functions that people have identified as missing from the API. In a user study, Calcite improved users' success rate by 40%.

Jadeite is a new Javadoc-like API documentation system that takes advantage of multiple users' aggregate experience to reduce difficulties that programmers have learning new APIs. Previous studies have shown that programmers often guessed that certain classes or methods should exist, and looked for these in the API. Jadeite's ldquoplaceholdersrdquo let users add new ldquopretendrdquo classes or methods that are displayed in the actual API documentation, and can be annotated with the appropriate APIs to use instead. Since studies showed that programmers had difficulty finding the right classes from long lists in documentation, Jadeite takes advantage of usage statistics to display commonly used classes more prominently. Programmers had difficulty discovering how to instantiate objects, so Jadeite uses a large corpus of sample code to automatically the most common ways to construct an instance of any given class. An evaluation showed that programmers were about three times faster at performing common tasks with Jadeite than with standard Javadoc.

Sometimes people cannot remember the names or locations of things on their computer, but they can remember what other things are associated with them. We created Feldspar, the first system that fully supports this associative retrieval of personal information on the computer. Feldspar's contributions include (1) an intuitive user interface that allows users to find information by interactively and incrementally specifying multiple levels of associations as retrieval queries, such as: "find the file from the person who I met at an event in May"; and (2) algorithms for collecting the association information and for providing answers to associative queries in real-time. A user study showed that Feldspar is easy to use, and suggested that it might be faster than conventional browsing and searching for these kinds of retrieval tasks. Feldspar could be an important addition to search and browsing tools.

The increasing quantity and complexity of in-vehicle systems creates a demand for user interfaces which are suited to driving. The steering wheel is a common location for the placement of buttons to control navigation, entertainment, and environmental systems, but what about a small touchpad? To investigate this question, we embedded a Synaptics StampPad in a computer game steering wheel and evaluated seven methods for selecting from a list of over 3000 street names. Selection speed was measured while stationary and while driving a simulator. Results show that the EdgeWrite gestural text entry method is about 20% to 50% faster than selection-based text entry or direct list-selection methods. They also show that methods with slower selection speeds generally resulted in faster driving speeds. However, with EdgeWrite, participants were able to maintain their speed and avoid incidents while selecting and driving at the same time. Although an obvious choice for constrained input, on-screen keyboards generally performed quite poorly.

We present Citrine, a system that extends the widespread copy-and-paste interaction technique with intelligent transformations, making it useful in more situations. Citrine uses text parsing to find the structure in copied text and allows users to paste the structured information, which might have many pieces, in a single paste operation. For example, using Citrine, a user can copy the text of a meeting request and add it to the Outlook calendar with a single paste. In applications such as Excel, users can teach Citrine by example how to copy and paste data by showing it which fields go into which columns, and can use this to copy or paste many items at a time in a user-defined manner. Citrine can be used with a wide variety of applications and types of data and can be easily extended to work with more. It currently includes parsers that recognize contact information, calendar appointments and bibliographic citations. It works with Internet Explorer, Outlook, Excel, Palm Desktop, EndNote and other applications. Citrine is available to download on the internet.

Abstract We introduce a technique for creating novel, enhanced thumbnails of Web pages. These thumbnails combine the advantages of plain thumbnails and text summaries to provide consistent performance on a variety of tasks. We conducted a study in which participants used three different types of summaries (enhanced thumbnails, plain thumbnails, and text summaries) to search Web pages to find several different types of information. Participants took an average of 67, 86, and 95 seconds to find the answer with enhanced thumbnails, plain thumbnails, and text summaries, respectively. As expected, there was a strong effect of question category. For some questions, text summaries outperformed plain thumbnails, while for other questions, plain thumbnails outperformed text summaries. Enhanced thumbnails (which combine the features of text summaries and plain thumbnails) had more consistent performance than either text summaries or plain thumbnails, having for all categories the best performance or performance that was statistically indistinguishable from the best.

We introduce a technique for creating novel, textually-enhanced thumbnails of Web pages. These thumbnails combine the advantages of image thumbnails and text summaries to provide consistent performance on a variety of tasks. We conducted a study in which participants used three different types of summaries (enhanced thumbnails, plain thumbnails, and text summaries) to search Web pages to find several different types of information. Participants took an average of 67, 86, and 95 seconds to find the answer with enhanced thumbnails, plain thumbnails, and text summaries, respectively. We found a strong effect of question category. For some questions, text outperformed plain thumbnails, while for other questions, plain thumbnails outperformed text. Enhanced thumbnails (which combine the features of text summaries and plain thumbnails) were more consistent than either text summaries or plain thumbnails, having for all categories the best performance or performance that was statistically indistinguishable from the best.

The Amulet user interface development environment makes it easier for programmers to create highly interactive, graphical user interface software for Unix, Windows and the Macintosh. Amulet uses new models for objects, constraints, animation, input, output, commands, and undo. The object system is a prototype instance model in which there is no distinction between classes and instances or between methods and data. The constraint system allows any value of any object to be computed by arbitrary code and supports multiple constraint solvers. Animations can be attached to existing objects with a single line of code. Input from the user is handled by "interactor" objects which support reuse of behavior objects. The output model provides a declarative definition of the graphics and supports automatic refresh. Command objects encapsulate all of the information needed about operations, including support for various ways to undo them. A key feature of the Amulet design is that all graphical objects and behaviors of those objects are explicitly represented at run time, so the system can provide a number of high level built-in functions, including automatic display and editing of objects, and external analysis and control of interfaces. Amulet integrates these capabilities in a flexible and effective manner.