A laboratory study of user characteristics and decision-making performance in end-user computing

A laboratory study using a simulated business setting was conducted to examine relationships among user characteristics, DSS usage patterns, and decision-making performance. MBA-student subjects self-selected into one of two categories: (1) “end-user programmers” who chose to use the DSS modeling language to develop personalized decision models, or (2) “command level users” who used only “canned” models and query language retrievals. The results show that early development of personalized decision models was positively related to the end-user's previous computer experience. The findings also support the contention that end-user programming improves decision-making performance. End-user programmers consistently outperformed the command level users in terms of their firm's stock price, market share, and return on assets.     

Utility and accuracy of smell-driven performance analysis for end-user programmers

This paper proposes a technique, called smell-driven performance analysis (SDPA), which automatically provides situated explanations within a visual dataflow language IDE to help end-user programmers to overcome performance problems without leaving the visual dataflow paradigm. An experiment showed SDPA increased end-user programmers’ success rates at finding performance problems and decreased the time required for finding solutions. Another study, based on using SDPA to analyze a corpus of example end-user programs, revealed that it is usually accurate at identifying performance problems. Based on these results, we conclude that SDPA provides a reliable basis for helping end-user programmers to troubleshoot performance problems, as well as a potential foundation for future work aimed at training users and at aiding code reuse.     

A component- and connector-based approach for end-user composite web applications development

Enabling real end-user development is the next logical stage in the evolution of Internet-wide service-based applications. Successful composite applications rely on heavyweight service orchestration technologies that raise the bar far above end-user skills. This weakness can be attributed to the fact that the composition model does not satisfy end-user needs rather than to the actual infrastructure technologies. In our opinion, the best way to overcome this weakness is to offer end-to-end composition from the user interface to service invocation, plus an understandable abstraction of building blocks and a visual composition technique empowering end users to develop their own applications. In this paper, we present a visual framework for end users, called FAST, which fulfils this objective. FAST implements a novel composition model designed to empower non-programmer end users to create and share their own self-service composite applications in a fully visual fashion. We projected the development environment implementing this model as part of the European FP7 FAST Project, which was used to validate the rationale behind our approach.     

Gneiss: spreadsheet programming using structured web service data

Web services offer a more reliable and efficient way to access online data than scraping web pages. However, interacting with web services to retrieve data often requires people to write a lot of code. Moreover, many web services return data in complex hierarchical structures that make it difficult for people to perform any further data manipulation. We developed Gneiss, a tool that extends the familiar spreadsheet metaphor to support using structured web service data. Gneiss lets users retrieve or stream arbitrary JSON data returned from web services to a spreadsheet using interaction techniques without writing any code. It introduces a novel visualization that represents hierarchies in data using nested spreadsheet cells and allows users to easily reshape and regroup the extracted structured data. Data flow is two-way between the spreadsheet and the web services, enabling people to easily make a new web service call and retrieve new data by modifying spreadsheet cells. We report results form a user study that showed that Gneiss helped spreadsheet users use and analyze structured data more efficiently than Excel and even outperform professional programmers writing code. We further use a set of examples to demonstrate our tool's ability to create reusable data extraction and manipulation programs that work with complex web service data.     

基于结构挖掘的论坛检索模型

随着互联网的发展,网络论坛中蕴涵着数量巨大且质量较好的知识资源。因此对论坛信息进行有效地检索具有重要应用价值。该文研究适合于论坛数据的检索模型,以期能够充分利用论坛平台累积的海量数据来满足用户的信息需求。针对论坛页面和普通新闻页面的区别,该文提出关键帖抽取算法和论坛线索重构算法来选择论坛中信息含量丰富的帖子,并利用得到的帖子构建检索系统。实验表明该文提出的方法能够有效地提升论坛检索系统的效果。     

An editing tool that manages device associations in an in-home environment

The forthcoming home environment will comprise numerous computationally enhanced artifacts that are autonomous, but interconnected via an invisible web of network-based services. The approach presented in this paper is to enable end users to make their own applications by linking such artifacts, which are treated as reusable components. A key requirement to achieve this is the availability of editing tools that meet the needs of different classes of users. A tool of this kind designed for end users is presented in this paper, together with the outcome of user evaluation sessions.     

A cloud-based platform to develop context-aware mobile applications by domain experts

Context-awareness enables the personalization of computer systems according to the users' needs and their particular situation at a given time. The personalization capabilities are usually implemented by programmers due to the complex processes that are involved. However, an important trend in software development is that more and more software systems are being implemented not only by programmers but also by people with expertise in other domains. Since most of the existing context-aware development toolkits are designed for programmers, non-technical users cannot develop these kinds of systems. The design of tools to create context-aware systems by users that do not have programming skills but are experts in the domain where the system is going to be deployed, will contribute to speed up the adoption of these kinds of services by the society. This paper presents a cloud-based platform to ease the development of context-aware mobile applications by people without programming skills. The platform has been designed to be used in a tourism domain. This way, tourism experts can send tourist information to mobile users according to their context data (indoor/outdoor location, language, and date and time range). An energy-efficient mobile app has been developed in order to obtain context data from the user's device and to receive personalized information in real time based on these data. The architecture and implementation details of the system are presented and the evaluation of the platform by tourism domain experts is discussed.     

Assisting web search using query suggestion based on word similarity measure and query modification patterns

One of the useful tools offered by existing web search engines is query suggestion (QS), which assists users in formulating keyword queries by suggesting keywords that are unfamiliar to users, offering alternative queries that deviate from the original ones, and even correcting spelling errors. The design goal of QS is to enrich the web search experience of users and avoid the frustrating process of choosing controlled keywords to specify their special information needs, which releases their burden on creating web queries. Unfortunately, the algorithms or design methodologies of the QS module developed by Google, the most popular web search engine these days, is not made publicly available, which means that they cannot be duplicated by software developers to build the tool for specifically-design software systems for enterprise search, desktop search, or vertical search, to name a few. Keyword suggested by Yahoo! and Bing, another two well-known web search engines, however, are mostly popular currently-searched words, which might not meet the specific information needs of the users. These problems can be solved by WebQS, our proposed web QS approach, which provides the same mechanism offered by Google, Yahoo!, and Bing to support users in formulating keyword queries that improve the precision and recall of search results. WebQS relies on frequency of occurrence, keyword similarity measures, and modification patterns of queries in user query logs, which capture information on millions of searches conducted by millions of users, to suggest useful queries/query keywords during the user query construction process and achieve the design goal of QS. Experimental results show that WebQS performs as well as Yahoo! and Bing in terms of effectiveness and efficiency and is comparable to Google in terms of query suggestion time.     

Accessible privacy and security: a universally usable human-interaction proof tool

Despite growing interest in designing usable systems for managing privacy and security, recent efforts have generally failed to address the needs of users with disabilities. As security and privacy tools often rely upon subtle visual cues or other potentially inaccessible indicators, users with perceptual limitations might find such tools particularly challenging. To understand the needs of an important group of users with disabilities, a focus group was conducted with blind users to determine their perceptions of security-related challenges. Human-interaction proof (HIP) tools, commonly known as CAPTCHAs, are used by web pages to defeat robots and were identified in the focus group as a major concern. Therefore, a usability test was conducted to see how well blind users were able to use audio equivalents of these graphical tools. Finally, an accessible HIP tool was developed which combines audio and matching images, supporting both visual and audio output. Encouraging results from a small usability evaluation of the prototype with five sighted users and five blind users show that this new form of HIP is preferred by both blind and visual users to previous forms of text-based HIPs. Future directions for research are also discussed.     

VoiceGrip: A Tool for Programming-by-Voice

In recent years, there has been an increase in the number of computer programmers suffering from Repetitive Strain Injury (RSI)—an umbrella term covering a series of musculoskeletal disorders caused by repetitive motion of the hands and arms. For those individuals, or any programmer with a handicap that precludes keyboard and/or mouse input, Speech Recognition (SR) is an attractive alternative because it could allow them to do their work without using such devices. Unfortunately, programming-by-voice with current SR systems is awkward because programming languages are not meant to be spoken. In this paper we describe various usability problems with programming-by-voice and show that none of the existing programming-by-voice tools address all of those barriers. We then present VoiceGrip, a programming-by-voice tool that adresses the widest range of programming-by-voice problems to date. VoiceGrip uses a unique approach where programmers first dictate code using an easy to utter pseudo-syntax, and then translate that automatically to native code in the appropriate programming language. The system has been downloaded by 343 individuals, and postings on a neutral programming-by-voice mailing list indicate that it is being used by at least some of them. We also present an experiment evaluating the performance of the system's symbol translation algorithm. In this experiment, the system exhibited low error rates in the range of 2.7% when confusion between homophonic symbols (i.e. symbols that have the same spoken pseudo code form) was ignored and 6.6% when confusion between homophonic symbols was taken into account. Finally, even though VoiceGrip is the tool that currently addresses the widest range of programming-by-voice problems, we conclude that a better tool can be developed by combining features of VoiceGrip with features of other existing programming-by-voice tools.     

End-User Development of Mashups with NaturalMash

Context: The emergence of the long-tail in the market of software applications is shifting the role of end-users from mere consumers to becoming developers of applications addressing their unique, personal, and transient needs. On the Web, a popular form of such applications is called mashup, built out of the lightweight composition of Web APIs (reusable software components delivered as a service through the Web). To enable end-users to build mashups, there is a key problem that must be overcome: End-users lack programming knowledge as well as the interest to learn how to master the complex set of Web technologies required to develop mashups. End-User Development (EUD) is an emerging research field dealing with this type of problems. Its main goal is to design tools and techniques facilitating the development of software applications by non-programmers.Objective: The paper describes the design and evaluation of NaturalMash, an innovative EUD tool for mashups (a mashup tool). NaturalMash aims at enabling non-professional users without any knowledge of programming languages and skills to create feature-rich, interactive, and useful mashups.Methods: The design of NaturalMash adopts a formative evaluation approach, and has completed three design and evaluation iterations. The formative evaluations utilize usability testing, think aloud protocol, questionnaires, observation, and unstructured interviews. Additionally, we compare the expressive power of naturalmash with the state-of-the-art mashup tools.Results: The results from the formative evaluations helped us identify important usability problems. From an assessment point of view, the results were promising and sggested that the proposed tool has a short and gentle learning curve in a way that even non-programmers are able to rapidly build useful mashups. Also, the comparative evaluation results showed that NaturalMash offers a competitive level of expressive power compared with existing mashup tools targeting non-programmers.Conclusion: As the evaluation results indicate, NaturalMash provides a high level of expressive power while it is still highly usable by non-programmers. These suggest that we have successfully achieved the objective of the proposed tool, distinguishing it from existing mashup tools that are either too limited or highly specialized for non-professional users.     

Discovering how end-user programmers and their communities use public repositories: A study on Yahoo! Pipes

ContextEnd-user programmers are numerous, write software that matters to an increasingly large number of users, and face software engineering challenges that are similar to their professionals counterparts. Yet, we know little about how these end-user programmers create and share artifacts in repositories as part of a community.ObjectiveThis work aims to gain a better understanding of end-user programmer communities, the characteristics of artifacts in community repositories, and how authors evolve over time.MethodAn artifact-based analysis of 32,000 mashups from the Yahoo! Pipes repository was performed. The popularity, configurability, complexity, and diversity of the artifacts were measured. Additionally, for the most prolific authors, we explore their submission trends over time.ResultsSimilar to other online communities, there is great deal of attrition but authors who persevere tend to improve over time, creating pipes that are more configurable, diverse, complex, and popular. We also discovered, however, that end-user programmers do not effectively reuse existing programs, submit pipes that are highly similar to others already in the repository, and in most cases do not have an awareness of the community or the richness of artifacts that exist in repositories.ConclusionThere is a need for better end-user programmer support in several stages of the software lifecycle, including development, maintenance, search, and program understanding. Without such support, the community repositories will continue to be cluttered with highly-similar artifacts and authors may not be able to take full advantage of the community resources.     

A visual programming language for XML manipulation

XML data flow has reached beyond the world of computer science and has spread to other areas such as data communication, e-commerce and instant messaging. Therefore, manipulating this data by non-expert programmers is becoming imperative and has emerged two alternatives. On one hand, Mashups have emerged a few years ago, providing users with visual tools for web data manipulation but not necessarily XML specific. Mashups have been leaning towards functional composition but no formal definitions have yet been defined. On the other hand, visual languages for XML have been emerging since the standardization of XML, and mostly relying on querying XML data for extraction or structure transformations. These languages are mainly based on existing textual XML languages, they have limited expressiveness and do not provide non-expert programmers with means to manipulate XML data. In this paper, we define a generic visual language called XCDL based on Colored Petri Nets allowing non-expert programmers to compose manipulation operations. The XML manipulations range from simple data selection/projection to data modification (insertion, removal, obfuscation, etc.). The language is oriented to deal with XML data (XML documents and fragments), providing users with means to compose XML oriented operations. The language core syntax is presented here along with an implemented prototype based on it.     

以用户为中心的可信终端身份管理模型

针对终端用户身份管理难题和现有的身份管理技术的不足,为了满足终端用户在任何情况下访问网络资源的客观需求,文章提出了以用户为中心的可信终端域内、跨域和开放网络环境下的身份管理系统模型,在此基础上设计了包括终端用户身份安全保护机制、身份管理流程、终端用户身份管理协议的终端用户身份安全保护方案,对协议进行了安全性分析和形式化分析,并与其他身份管理模型的安全性进行了比较,结果表明该模型能够安全地管理用户身份和实现各种环境下的访问控制。     

面向对象方法在流化催化裂化动态系统仿真中的应用（Ⅱ） 面向对象程序设计和系统仿真

本文引入面向对象机制为流化催化裂化（ＦＣＣ）动态系统仿真问题求解建立了一个抽象通用的类层次，并应用ＴｕｒｂｏＣ＋＋面向对象程序设计语言开发了ＦＣＣ动态系统仿真程序。仿真模型采用９阶状态空间模型，仿真算法选择４阶Ｒｕｎｇｅ－Ｋｕｔｔａ方法，仿真曲线使用Ｂｏｒｌａｎｄ图形接口（ＢＧＩ）工具显示。仿真结果是令人满意的。作者认为，由于用面向对象程序设计语言编制的程序具有易阅读、易维修、易扩充和通用性强等优点，故用面向对象程序设计语言代替传统的过程式语言开发实际工业生产过程仿真软件，将使软件开发者和最终用户都受益非浅，它必将成为一种新的趋势。     

Confronting database complexities

Database technology is exploding, as the hierarchical and relational models give way to object-oriented, distributed heterogeneous, and other kinds of specialized models. Designers, programmers, and users need new tools     

Modular Verification of Open Features Using Three-Valued Model Checking

Feature-oriented programming organizes programs around features rather than objects, thus better supporting extensible, product-line architectures. Programming languages increasingly support this style of programming, but programmers get little support from verification tools. Ideally, programmers should be able to verify features independently of each other and use automated compositional reasoning techniques to infer properties of a system from properties of its features. Achieving this requires carefully designed interfaces: they must hold sufficient information to enable compositional verification, yet tools should be able to generate this information automatically because experience indicates programmers cannot or will not provide it manually. We present a model of interfaces that supports automated, compositional, feature-oriented model checking. To demonstrate their utility, we automatically detect the feature-interaction problems originally found manually by Robert Hall in an email suite case study.Research done while at Brown University.