A Data Model to Support End-User Software Engineering
Christopher Scaffidi Carnegie Mellon University
Questions for the panel Some areas where I would appreciate suggestions: • What aspects of this work would be of most interest to the ICSE community (in future research papers)? • For any potential problems that you see in the work, what solutions can you suggest?
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Target audience • In 2012, we project that there will be 90 million computer end users (“EUs”) in American workplaces. • Of these, at least half will create spreadsheets, databases, and/or web applications. These are called end-user programmers (“EUPs”). [5] • Both EUs and EUPs will benefit from the proposed research, though the proposed research is primarily aimed at EUPs (including EUs who become EUPs because of the research).
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Contextual inquiry: What are the problems of EUs and EUPs? Observed 3 administrative assistants, 4 managers, and 3 webmasters/graphic designers (1-3 hrs, each) [3][9]
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How can EUPs validate web forms if they do not know JavaScript? Is the input valid? “EDSH 225” Is the input nearly valid? “EDXH 225” Does it just need reformatting? “Smith 225” Or is it obviously badly invalid? “Robotics Institute”
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Other tasks, other data, other problems • When building a staff roster by merging data sources into a single spreadsheet, one of the EUs: – Had to manually transform data to consistent format (e.g.: Put person names in Lastname, Firstname format) – Had to scrutinize data to identify questionable values that deserved double-checking (e.g.: A first name with 15 characters might be right) – Had to manually check for (near-) duplicates (e.g.: “Scaffidi, Christopher” and “Scaffidi, Chris”)
• We and research collaborators identified many additional data validation and data reuse tasks that were poorly supported by existing tools. [3][7][9] 6
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Underlying problem: abstraction mismatch • Tools support strings, integers, floats, sometimes dates. • Problem domain involves higher-level categories of data: – – – –
University names Person names CMU phone numbers CMU room numbers
“Carnegie Mellon”, “CMU” “Scaffidi, Christopher”, “Chris Scaffidi” “8-1234”, “x8-1234” “WeH 4623”, “Wean 4623”
• These data categories are: – – – – – 7
Human-readable Short (~ 1 input field) Multi-format Sometimes ambiguous / fuzzy (non-binary scale of validity) Often particular to certain groups of people introduction ● prototype ● proposed work ● evaluation
A New Direction: Create a new abstraction for each category of data • Like software “libraries,” implementations of these abstractions could be reused in many programs. • Abstractions would need to include functionality for: – Recognizing instances of the category (for automating data validation)
– Transforming instances among various formats (for automating data reformatting)
– Testing instances for equality (for automating removal of duplicates) 8
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A New Direction: Other requirements for abstractions • EUPs over a range of programming expertise must be able to create custom new abstractions. • Flexibility: – Abstractions must capture fuzziness when recognizing instances of the category and when testing equivalence. – EUPs must have the option of configuring abstractions to learn exceptional cases.
• Sharability: – EUPs must still be able to share and find useful abstractions even as the number of abstractions grows.
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Thesis The proposed data model and development environment will enable end-user programmers to implement and share custom abstractions for flexibly recognizing, transforming and equivalence-testing values in categories of short, human-readable data. The model and environment will help end-user programmers to more quickly and correctly validate and reuse data than is possible through currently practiced methods.
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Topes •
Tope = an abstraction implementation for a data category – Greek word for “place,” because each corresponds to a data category with a natural place in the problem domain
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Topes in practice: – EUPs create new topes by using the basic tope editor (or by writing topes in another language, such as JavaScript) – EUPs publish topes on repositories. – Other EUs & EUPs download topes to their local cache. – Tool plug-ins let EUs & EUPs browse their local cache and associate topes with variables and input fields. – Plug-ins get topes from local cache and use them to recognize, transform, and equivalence-test data.
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Related Work: Existing approaches do not meet the requirements. • Regexps / grammars / data detectors recognize data but do not specify how to transform data • Types: – A value is or is not a valid instance of a type (non-fuzzy) – If invalid at compilation, values cannot become valid at runtime – Typed languages are probably difficult for EUPs who are uncomfortable with untyped scripting languages.
• Research on units (e.g.: Slate) and constraint systems (e.g.: Cues) typically only apply to numeric data in certain applications (e.g.: spreadsheets). • And none of these has built-in support for helping users decide which abstractions to trust, so sharing is impeded. 12
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Outline • • • • •
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Introduction Related work Prototype Proposed work Evaluation
How could flexible formats be expressed?
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Sample task: web form validation The painful old way • Drag widgets and validator onto page, select a regexp, customize if desired.
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Sample task: web form validation Results of the painful old way • Invalid inputs cause a hard-coded message to appear. Oops, forgot to enter a message at design-time.
• For valid inputs, no error message appears.
Hm, didn’t realize the area code was optional. What if I want to allow campus phone numbers?
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Sample task: web form validation The wonderful new way • Drag widgets and validator onto page, select a format, customize if desired.
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Sample task: web form validation Creating this format took 55 seconds
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Sample task: web form validation Results of the new way • Invalid inputs cause a targeted message to appear.
• Inputs that violate an always or never constraint cannot be submitted to the server. • Inputs that violate an often constraint cause a warning, which the application user can override.
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Prototype implementation System block diagram Spreadsheet
Microsoft Excel Plug-in
Web application Validator
Format editor
Microsoft Visual Studio.NET Plug-in Parser
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Expressiveness evaluation • Four administrative assistants’ use of a web browser was logged for three weeks, resulting in nearly 6000 sample data values that they typed into web forms. • Not logged verbatim: characters were generalized – Eg:
[email protected] Aa{7}0@a{5}.a{3}
• We manually grouped values into 19 semantic families (eg: email address) based on widget’s HTML name and words visually nearby to the widgets • Created and tested formats for 14 families (4250 values)
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– Omitted: username/passwords and long blocks of “text” – Inference & testing features were not used during format creation introduction ● prototype ● proposed work ● evaluation
Expressiveness evaluation results • 9 families needed 1 format each; 5 needed 2 formats each • The only error attributable to editor expressiveness: – 1 of the 4250 test values had a trailing period on a street type (in an address line) – This particular version of the editor had no way to say that a part could contain a period but only at the end
• After support for multiple formats is added, then the editor as a whole will be evaluated for usability. [6]
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Outline • • • • •
Introduction Related work Prototype Proposed work Evaluation
Generalizing the prototype: A lightweight data model + A development environment to help EUPs create, share and use topes
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Proposed data model • 1 tope implementation contains executable functions: – 1 isa:string[0,1] function per format, for recognizing instances of the format – 0 or 1 eqc:string x string[0,1] function per format, for testing equivalence of two values in a format (default is a binary test for being exactly identical) – 0 or more trf:stringstring function linking formats, for transforming values form one format to another
• A lightweight data model… – Only contains 3 kinds of functions (isa/eqc/trf) – These correspond to the operations that people had to keep performing manually in our studies. 23
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Example tope Notional representation • An example tope for CMU room numbers – 3 isa functions, up to 3 eqc functions, 4 trf functions – A tope’s eqc and trf functions can be omitted if desired
Formal building name & room number
Building abbreviation & room number
Elliot Dunlap Smith Hall 225
EDSH 225
Colloquial building name & room number Smith 225
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Proposed development environment Functional decomposition diagram Development Environment
Basic Topes Editor
Repository Software
Publishing Tools
Plug-Ins
Search Tools
EUPs implement topes in basic topes editor (or JavaScript), then publish in repositories. Other EUs and EUPs search for topes, download them, then use them through plug-ins.
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Proposed development environment Enhanced basic topes editor Development Environment
Basic Topes Editor
Repository Software
Publishing Tools
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Plug-Ins
Search Tools
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Proposed work Enhancing the basic topes editor • Extend isa support – Improve error message generation
• Add trf support – EUPs will specify a series of steps: • Select a part, select an operator • Operators: permutation, lookup, arithmetic, capitalization
– Add (regression) testing features to facilitate consistency
• Add eqc support – For each part, EUPs will specify a comparison operator, returning value in [0,1], and these will be multiplied. • Operators: exactly identical, case-insensitive comparison, ~arithmetic distance, ~edit distance 27
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Proposed development environment Publishing tools Development Environment
Basic Topes Editor
Repository Software
Publishing Tools
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Plug-Ins
Search Tools
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Proposed Work Publishing topes in repositories • Clients will have a list of “known” repository servers – Generally pre-configured to include a global server at CMU – Organizations will configure clients to include the organizational server – EUs and EUPs will be able to add new servers to their list
• To support publishing/searching, the repository will house meta-information about topes, including… – a human-visible non-unique name & description – an internally-used globally unique id (guid) based on the tope’s URL in the repository
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Proposed development environment Search tools Development Environment
Basic Topes Editor
Repository Software
Publishing Tools
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Plug-Ins
Search Tools
Normalization
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Proposed work Searching for relevant topes • Search by keyword: – Search tope name and description – And match based on words that are visually near to topes
• Search by groups of people: – Within an organization, or by author’s email domain – Within spaces that are “group-private”
• Search by groups of topes: – “If you liked this tope, you may also like XYZ” – Similar to Amazon.com’s product recommendations
• Search by example: – “Find me a tope that recognizes 412-555-1212” – For efficiency, filter based on “signature” (\d{3}-\d{3}-\d{4}) 31
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Proposed work Searching for trustworthy topes Evidence [8]
EUs and EUPs may trust topes:
Search features
Explicit formal roles Prior performanc Model e of motivation Group membershi Reputation p
Created by their organization’s system administrators. From people who have previously supplied good topes. From vendors that care about brand image.
Search by tope author
References
That present a list of high-profile people who like the topes. That are inspected and certified by a third party. That are actively maintained—that is, for which improved versions are regularly available. That are implemented in a familiar language/platform.
Certification Social context
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From people who are known to have a similar background. That earned anonymous votes of confidence.
Search by tope ratings (either anonymous or not) Search by tope publication date and execution platform
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Proposed development environment Enhanced plug-ins Development Environment
Basic Topes Editor
Repository Software
Publishing Tools
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Plug-Ins
Search Tools
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Proposed work Enhancing plug-ins • Target tools – Microsoft Excel – Microsoft Visual Studio.NET – Robofox • Operations supported – Assertions – Transformation – De-duplication
run isa on selected cells run trf on selected cells run eqc on selected cells, cluster the cells
• Each will support basic editor topes & JavaScript topes 34
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Proposed work Recognizing exceptions in plug-ins • Tope creators might overlook values. • From the standpoint of a tope format, these “normal” values are exceptional cases that need to be tolerated. • Simple approach: Record a whitelist of exceptions • More sophisticated: For each format, record exceptions, infer a format (new isa function), and average this function’s score with the raw function’s score • Exceptional values can be incorporated into the tope in the local cache and/or, at EUP’s discretion, propagated to the repository of the tope’s master copy 35
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Outline • • • • •
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Introduction Related work Prototype Proposed work Evaluation
Examples Experiments Field testing
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Evaluation Expressiveness – Identify test tasks based on previous studies; create topes for data involved in those tasks Creation of topes by EUPs – Controlled experiment in which students & staff create topes Usefulness for tasks – Controlled experiment in which students & staff use topes to perform the test tasks Flexibility of topes – Test the topes created by participants on test data drawn from EUSES spreadsheet corpus Sharability of topes – Field testing in which several dozen students & staff will install and use the environment 37
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Referenced papers Conference papers [1] [2] [3] [4]
[5]
C. Scaffidi. Unsupervised Inference of Data Formats in Human-Readable Notation. Proceedings of 9th International Conference on Enterprise Integration Systems (ICEIS'07), 2007, to appear. C. Scaffidi, K. Bierhoff, E. Chang, M. Felker, H. Ng, C. Jin. Red Opal: Product-Feature Scoring from Reviews. Proceedings of 8th ACM Conference on Electronic Commerce (ACMEC'07), 2007, to appear C. Scaffidi, A. Cypher, S. Elbaum, A. Koesnandar, and B. Myers. Scenario-Based Requirements for Web Macro Tools. Submitted for publication, 2007. C. Scaffidi, A. Ko, B. Myers, M. Shaw. Dimensions Characterizing Programming Feature Usage by Information Workers. VL/HCC'06: Proceedings of the 2006 IEEE Symposium on Visual Languages and Human-Centric Computing, pp. 59-62, 2006. C. Scaffidi, M. Shaw, and B. Myers. Estimating the Numbers of End Users and End User Programmers. VL/HCC'05: Proceedings of the 2005 IEEE Symposium on Visual Languages and Human-Centric Computing, pp. 207-214, 2005.
Other papers [6] [7]
[8] [9]
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C. Scaffidi, B. Myers, M. Shaw. The Topes Format Editor and Parser, Technical Report CMU-ISRI-07-104, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, May 2007. C. Scaffidi, B. Myers, and M. Shaw. Trial By Water: Creating Hurricane Katrina "Person Locator" Web Sites. In Leadership at a Distance: Research in Technologically-Supported Work (S. Weisband, ed), Lawrence Erlbaum, pp. 209-222, 2007. C. Scaffidi, M. Shaw. Toward a Calculus of Confidence. First International Workshop on the Economics of Software and Computation, co-located with ICSE'07, 2007, to appear. C. Scaffidi, M. Shaw, B. Myers. Games Programs Play: Obstacles to Data Reuse, 2nd Workshop on End User Software Engineering (WEUSE), 2006.
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Thank You… •
…to the symposium committee/panel for the opportunity to present
•
…to many people for helpful suggestions
Marwan Abi-Antoun
Margaret Burnett
Martin Erwig
Andy Ko
Mary Beth Rosson
Robin Abraham
Owen Cheng
George Fairbanks
Thomas LaToza
Mary Shaw
Matt Bass
Ciera Christopher
Thomas Green
Alon Lavie
Jeff Stylos
Nels Beckman
Michael Coblenz
Josh Gross
Henry Lieberman
Dean Sutherland
Kevin Bierhoff
Allen Cypher
Greg Hartman
Larry Maccherone
Steve Tanimoto
Alan Blackwell
Uri Dekel
Jim Herbsleb
Brad Myers
Susan Wiedenbeck
Barry Boehm
Sebastian Elbaum
John Hosking
John Pane
•
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…to NSF and EUSES for funding (ITR-0325273 and CCF-0438929)
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Questions for the panel Some areas where I would appreciate suggestions: • What aspects of this work would be of most interest to the ICSE community (in future research papers)? • For any potential problems that you see in the work, what solutions can you suggest?
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Survey of EUPs: Better data-manipulation features needed • Asked 831 information workers about use of 23 features in 5 tools (eg: creating spreadsheet macros, database stored procedures, and web forms) [4][9] • The most widely used features were related to manipulating linked structures of data (eg: database tables) rather than imperative or macro programming • Yet respondents complained about these features: – “Not always easy to move sturctured [sic] data or text” – “Not always integrated a lot of data manipulation redundant” – “Information entered inconsistently into database fields by different people leaves a lot of database cleaning” 42
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Interviews of web site creators: Confirmation of specific problems • Interviewed 6 people involved in creating “person locator” web sites after Hurricane Katrina [7][9] • Many omitted data validation on web forms – Hard to detect that “12 Years old” is an invalid street address (what would the regexp look like?)
• “Aggregator” sites were built to scrape and consolidate data from numerous person locator sites. – Hard to transform data into a single consistent format – Hard to identify probable duplicates in the merged data set
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Sample task: validating person names Customizing constraints in our prototype • User can add/edit constraints
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Benefits of the format editor • Exotic regexp notation is replaced with sentence-like screen prompts. • Soft constraints (“often”) are supported. • Negation constraints (“never”) are supported. • In terms of expressiveness, Augmented context-free grammars > context-free grammars > regexps But is the expressiveness adequate for common data? 45
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