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Archived Project News

CTAT 2.11 Released March 28, 2011

includes the following new features and Flash components:

  • Revised logging preferences and new channels for logging
  • On exiting the tools, CTAT no longer prompts you to save your behavior graph file if you haven't modified it.
  • New Flash components: CommCalculator, CommDragNDrop, CommEquationSolver, CommFractionBar, CommGrapher, CommHideableHintWindow, CommVideoPlayer
  • The CommShell has been optimized to be faster and smaller in size, and its visual style has been moved out into other components.

Call for Applications - 7th Annual PSLC LearnLab Summer School March 25, 2011

To be held at Carnegie Mellon University, Pittsburgh, PA, USA July 25-29, 2011.
The application deadline is April 3, 2011. If you're interested in learning how to author tutors with CTAT, please consider applying.

CTAT 2.10 Released September 23, 2010

This release includes the following new features and Flash components:

  • Variable Table Viewer, a new tool for viewing and inspecting variables in example-tracing tutors. It can be used to assist in writing formulas and to view variables while setting the start state (useful for Flash tutors).
  • NtpClient: Flash tutors now log a custom field with each transaction that stores the time as provided by the server using the Network Time Protocol (NTP) standard.
  • New functions for use in formula matching
  • New Flash components, CommPieChart and CommLabel
  • Logging for untutored actions
  • Updated Jess rules for fraction addition cognitive tutor example

CTAT 2.9 Released June 14, 2010

This release is primarily a bug-fix release, but also includes some new features for the authoring tools and Flash components.

  • Changed the state-triggered TPA algorithm so that hintless optional steps don’t prevent a TPA from being triggered
  • CTAT can replace a student's correct input on a step with an expression you define. You can use this feature to simplify a mathematical expression for the student.
  • Smaller “Edit Student Input Matching” dialog
  • Many improvements to the CommNumberBar Flash component, including a new partition type that allows the student to subdivide each whole-number portion of the line into fractional parts.

CTAT workshop at ICLS 2010 April 5, 2010

ICLS 2010 Pre-conference Workshop
Tuesday, June 29, 9:00AM 12:30PM

Intelligent tutoring systems guide learners as they practice a complex cognitive skill. They have been shown to enhance learning in a range of domains, and are increasingly being used as platforms for learning science experiments. This workshop provides a hands-on tutorial introduction to building tutors using the freely available Cognitive Tutor Authoring Tools (CTAT). Using CTAT, authors can create a new type of tutors, example-tracing tutors, without programming. No background in computer science is required.


Vincent Aleven
Associate Professor of Human-Computer Interaction

Jonathan Sewall
Project Director

Human-Computer Interaction Institute
Carnegie Mellon University
5000 Forbes Ave.
Pittsburgh, PA 15213

CTAT 2.8 Released February 15, 2010

This release includes many new features and bug fixes for the authoring tools and Flash components. Some highlights:

  • Behavior graph rewiring: change the structure of a graph by dragging and dropping the end of a link to point to another node.
  • Knowledge tracing: CTAT now calculates the probability that a student knows a particular skill (“pKnown”) for steps in an example-tracing tutor where skill names are defined.
  • Improvements to the link inspector
  • State- and link-triggered tutor-performed actions
  • New Flash components: CommSkillBar, CommHintButton, CommHintWindow

CTAT 2.7.1 Released October 19, 2009

This release fixes a critical bug in Flash client-side logging, and introduces more improvements to tab order and focus management for Flash components.

CTAT 2.7 Released September 22, 2009

This release includes many new features and bug fixes for the authoring tools and Flash components. Some highlights:

  • Behavior graph editing improvements: insert a step anywhere in a graph; (re-)demonstrate the contents of an existing step.
  • Beta version of the Link Inspector: click a step in a behavior graph and its contents are displayed in a single panel.
  • New Flash components, CommNumberBar and CommImage.
  • Support for specifying tab order in Flash tutors.

Martina Rau wins Best Student Paper Award at 2009 AIED conference August 18, 2009

First-year HCII graduate student and CTAT user Martina Rau won the Best Student Paper Award at the 14th International Conference on Artificial Intelligence in Education, AIED 2009, which was held in Brighton, UK, July 6-10. Her paper, entitled "Intelligent tutoring systems with multiple representations and self-explanation prompts support learning of fractions", was co-authored with Vincent Aleven and Nikol Rummel, and features CTAT example-tracing tutors with Flash interfaces that the author created for each condition of the experiment:

We investigated the value of MGRs [multiple graphical representations] for fractions learning in the context of a proven intelligent tutoring system (ITS) technology, namely, Cognitive Tutors [19-21]. Specifically, we developed a set of example-tracing tutors for fractions learning, a type of tutors that are behaviorally similar to Cognitive Tutors, but that rely on examples of correct and incorrect solution paths rather than on a cognitive model underlying student behavior. We created these tutors with the Cognitive Tutor Authoring Tools (CTAT [22]).

CTAT 2.6.1 Released July 10, 2009

CTAT 2.6.1 is primarily a bug-fix release. CTAT will now vary step-out-of-order feedback messages based on whether or not the tutor is configured to highlight the correct step. Also included in the release is a new tutor template for NetBeans version 6.7 (the current NetBeans release).

CTAT 2.6 Released June 3, 2009

CTAT 2.6 includes many new features and bug fixes for the authoring tools and both Flash and Java widgets. Some highlights:

  • Logging error-checking for Java tutors
  • Changes to formula grammar, which affects how the formulas in expression-matching steps are parsed and interpreted
  • New CTAT formulas for expression matching
  • An updated Jess Eclipse plugin
  • Tutor-performed actions for Jess cognitive tutors
  • A student-starts-here feature for making any state a starting state and creating worked examples
  • A Flash feature called "the scrim", a partially transparent screen which appears when the tutor is not yet ready for a student to start working on a problem or when the tutor disconnects from the Tutoring Service. Whenever the scrim is visible, all tutor components are disabled.
  • A new Flash component, CommImage
  • Updated Flash example tutors, including a new one for tutoring conversion factors

... and much more!

Last call for applications: the 5th Annual PSLC Summer School at CMU March 29, 2009

Scholarships are still available for the 5th Annual PSLC LearnLab Summer School to be held at Carnegie Mellon University, Pittsburgh, PA, USA.

  • When: Monday, July 13, 2008 - Friday, July 17, 2008
  • Cost: $950 General Fee / $250 for Graduate Students. Many scholarships available.

From the Call for Applications: “We invite applications for participation in an intensive 1-week summer school on technology-enhanced learning experiments and building intelligent tutoring systems. The summer school will provide a conceptual background and considerable hands-on experience in developing, running and analyzing technology-enhanced learning experiments.”

Come build tutors with us!

CTAT 2.5.1 Released November 24, 2008

CTAT 2.5.1 is primarily a bug-fix release. Some significant changes are:

  • Improved hint-after-error policy
  • Millisecond timestamps in logging: both Java and Flash tutors now log timestamps for “tool” and “tutor” messages with millisecond-level precision
  • Tutor-performed steps will now use selection, action, and input from the “matcher” column of the Edit Student Input Matching dialog whenever the matcher is either the Exact matcher or the Formula matcher with an operator of “=”.
  • CommTextArea, CommTextInput background color is now more easily configurable in Flash CS3. The background color of these components defaults to white.
  • CommTextArea's “html” parameter now enables HTML rendering within the component.
  • CommShell values for correct/incorrect/hint color no longer default to black in Flash CS3.

CTAT 2.5 Released September 8, 2008

In addition to bug fixes, new features include:

  • Windows Vista-compatible installer
  • Support for ordering constraints in example-tracing tutors
    • Link-group editor for setting and editing ordering constraints
    • Link-group visualization in the behavior graph
  • Revamped student-input matching dialog
  • Optional steps, and support for minimum and maximum numbers of times steps should be performed.
  • Even better support for formulas

CTAT 2.4 Released June 20, 2008

New features include:

  • Improved logging from Java and Flash tutors
  • Better support for formulas
  • Three new Java widgets: DorminPicture, DorminAudioButton, and DorminDrawingPad
  • Bug fixes involving the behavior of example-tracing tutors

Downloads temporarily offline August 27, 2008

Please contact us if you'd like to download CTAT.

Open position with CTAT: Flash research programmer April 29, 2008

We are looking for a research programmer to help our lab in the development of web-based tutoring software. The candidate's duties will include the development of computer-based tutors, using the Cognitive Tutor Authoring Tools (CTAT), maintaining and extending the Flash-based tools within CTAT, and helping to create, maintain, and extend a website with CTAT-built tutors for middle-school math.

PSLC Summer School Registration is Open February 26, 2008

The PSLC Summer School is an intensive 1-week course on technology-enhanced learning experiments and building intelligent tutoring systems. The summer school will provide a conceptual background and considerable hands-on experience in developing, running and analyzing technology-enhanced learning experiments. This year's summer school will be held July 7-11, 2008 at Carnegie Mellon University in Pittsburgh, PA, USA.

In the Tutor Development track, CTAT project leads and staff will be present to help you develop an intelligent tutor with CTAT:

In the tutor development track, your goal will be to implement a prototype computer-based tutor, using authoring tools developed by PSLC reseachers, such as CTAT (the Cognitive Tutor Authoring Tools) which supports the creation of intelligent tutoring systems, or TuTalk, which is used to develop tutorial dialogue systems that interact with students in natural language.

Participation is free. The application deadline is midnight April 2, 2008.

CTAT 2.3 Released November 30, 2007

New features include:

  • "Start state" editing at any time
  • Formulas, a powerful new method for adding flexibility and generality to an example-tracing tutor
  • Beta release of the "Number Line" Flash component
  • Logging updates
  • Numerous bug fixes

New version of Flash Logging Library September 14, 2007

We've released an update to the Flash Logging Library, v2.3.8. This version contains support for logging media events related to video and audio.

CTAT Survey - Tell us what you think! August 8, 2007

We want to know what you think of CTAT. Have you used CTAT? Was it helpful? Usable? What could we do to make it better? Tell us on our survey. (It's anonymous and only 10 questions long.)

CTAT 2.2 Released June 13, 2007

New features include:

  • Capability to view logs of tutor usage in Excel.
  • Usability improvements for behavior graph editing.
  • Mass production improvements
  • Four new Flash components (CommButton, CommScore, CommTimer, and CTATPreloader)

CTAT 2.1 Released May 11, 2007

New features include:

  • Logging of both Flash and Java tutors in XML that conforms to version 4 of the tutor_message DTD.
  • Extensible 'matchers' for comparing actual student input with a production rule's prediction of student input in a cognitive tutor.
  • More nimble navigation of a behavior graph
  • Simplified default working memory structure for cognitive tutors
  • More system status messages that are displayed in the Jess console
  • Numerous bug fixes

CTAT 2.0 (beta) Released February 06, 2007

New features include a more powerful Example-tracing algorithm; reorganized program menus; separation of tutor 'type' and 'authoring mode'; behavior graph visualization with JGraph; support for showing and hiding interface elements during tutoring; and the first release of the tutoring service, a new server-client architecture that further separates the tutoring engine from the student interface, allowing for fully functional light-weight tutors.

CTAT 1.6.3 Released December 14, 2006

CTAT 1.6.3 is a maintenance release that addresses bugs in CTAT 1.6.2. All users of CTAT 1.6.x are recommended to upgrade.

PSLC Summer School 2007 Dates December 4, 2006

Next year's PSLC Summer School will be held June 18–22, 2007. We'll post a link to the 2007 application here when it becomes available. The likely application deadline is early to mid-February 2007.

CTAT 1.6.2 Released November 15, 2006

CTAT 1.6.2 is primarily a maintenance release that addresses a number of bugs in CTAT 1.6.1. All users of CTAT 1.6.x are recommended to upgrade to 1.6.2.

CTAT version 1.6.2 also includes two new features: a modified DorminComposer Java widget that allows a student to delete answers; and support for integrating CTAT Example-tracing Tutors in Carnegie Learning 2006 curricula units.

Summer School 2007 Pre-Announcement September 8, 2006

Over 30 participants attended this year's PSLC Summer School, a week-long course that focused on creating technology-enhanced courses and learning experiments, and on the tools used to design, implement, run, and analyze them. This November, PSLC organizers will announce the details of next year's summer school. We'll post the specifics here as they become available.

Announcing CTAT workshops August 20, 2006

The CTAT Team will be offering a series of small workshops on authoring and delivering CTAT tutors. Our first workshop will be on Thursday, August 24th, 2-4PM (Newell-Simon Hall room 1109 at CMU). The title will be Is CTAT right for me? Understanding your options for building CTAT tutors in Java and Flash.

Please let us know if you'll be attending, and mention any questions you have or topics you'd like to explore—we'll do our best to answer them at the workshop. If they're beyond the scope of Thursday's workshop, we might plan a future workshop around them.

Update: Slides from the first workshop are available here.

CTAT 1.6.1 Released July 26, 2006

CTAT 1.6 Released June 23, 2006

New features include Jess-Flash integration for creating cognitive tutors in Flash, better support for customizing tutor behavior, improved Jess performance, tutor-performed steps, new Flash components, and Simulated Student, a machine-learning agent that facilitates authoring of Cognitive Tutors.

2nd Annual PSLC LearnLab Summer School - Last Call for Applications
May 18, 2006

An intensive, five-day course focused on creating technology-enhanced courses and learning experiments and on tools to support the design, implementation, running, and analysis of such experiments. The course is free, and will be held at Carnegie Mellon University, Pittsburgh, PA, USA, from Monday, July 31, 2006 to Friday, August 4, 2006. The application deadline has been extended to May 26. Notification of acceptance will be given by June 2. Update: Application deadline has passed. Thanks to all that applied.

Download new papers about CTAT May 5, 2006

Two recently accepted conference papers are now available from the CTAT publications page. The first, to appear in the proceedings of the 8th International Conference on Intelligent Tutoring Systems (ITS 2006), reports on the results of a small-scale study that examined efficiency gains in tutor development with CTAT. The second, to appear in the proceedings of the 6th IEEE International Conference on Advanced Learning Technologies (ICALT 2006), details a number of recent CTAT innovations through case studies. Both papers provide overviews of the current state of the CTAT project.

Milestones in the History of Cognitive Tutors April 12, 2006

Explore two decades of research and development history on Cognitive Tutors. The timeline also provides audio clips and links to research papers.

CTAT 1.5.1 Released December 12, 2005

CTAT 1.5.1 is an interim release that fixes two bugs for unordered groups and advanced student input matching.

CTAT 1.5 Released November 3, 2005