Timeline of Cognitive Tutor History

John R Anderson completes the ACT* theory of learning and problem solving. The theory holds that a cognitive skill consists of numerous rules that each relate task goals and task states to actions and consequences. These rules are formalized as production rules that store goal-oriented knowledge. As opposed to declarative knowledge, procedural knowledge is stored in production rules.

Anderson's The Architecture of Cognition is published a year later.

Anderson and colleagues complete two cognitive tutors--the Lisp Programming Tutor and the Geometry Proof Tutor (GPT)--to validate the ACT* theory of cognition in a computer tutor.

The Lisp tutor is used in a mini-course taught by its developers at Carnegie Mellon University. Besides being a useful tool for learners, the tutor also aids Anderson and Corbett as they research the effectiveness of intelligent tutoring and the validity of the ACT* theory. In a study, students that worked with the Lisp Tutor completed problems as little as one third of the time required by students working in programming environment without the tutor. Students that used the tutor also score 25% higher on subsequent tests (Corbett & Anderson, 1991).

The Lisp tutor remains in use in the self-paced course until 1999.

For his dissertation, Kenneth Koedinger embarks on the ANGLE (A New Geometry Learning Environment) Geometry Tutor Project to test novel assumptions about learning. The new tutor will then be tested in the classroom. Like GPT, ANGLE is a problem-solving environment where students construct graphical representations of Euclidean proofs. Unlike GPT, ANGLE is a based on a cognitive model that models--and therefore facilitates thinking with--an expert-like representation of target knowledge.

By the time ANGLE is piloted at Langley High School in 1991, Pittsburgh city high schools have adopted a new curriculum that de-emphasizes proof; this makes long-term use of the tutor in the classroom unrealizable.

• Professor Kenneth Koedinger reflects on piloting ANGLE and teaching at Langley High School (07m:38s)
• Professor Kenneth Koedinger on the hardware used for ANGLE (01m:38s)
• Professor Kenneth Koedinger on ANGLE architecture and speed (01m:41s)

Using cognitive tutors they've developed, John Anderson and Al Corbett teach Lisp, Pascal, Prolog in a self-paced course at Carnegie Mellon University. The course is later modified to include Lisp and Prolog, and remains in use until 1999.

The journal Cognitive Science publishes Anderson, Conrad, and Corbett's paper titled "Skill Acquisition and the LISP Tutor" (1989), in which the authors report on experiments completed using the LISP tutor to study cognition. Their results confirm theories of the production rule as "the right unit of analysis in understanding the acquisition of a skill" (p 493). The researchers also conclude that when the structure of the domain is factored out, skill acquisition is simple: "Once the units of knowledge are identified, acquisition of the skill can be predicted by composing simple learning functions for these units" (p 493). This initial work on the topic of what would be known as "knowledge tracing" leads to empirical validation of the concept and incorporation of knowledge tracing in subsequent cognitive tutors.

With the help of Pittsburgh public school teacher Bill Hadley, the Carnegie Mellon research team sets out to develop a mathematics curriculum into which their tutors would be positioned.

Around this time, the Pittsburgh Urban Mathematics Project, or PUMP, is formed. PUMP is a collaboration between the ACT Research Group of Carnegie Mellon University's Psychology Department, researchers from Carnegie Mellon's Human-Computer Interaction Institute, and teachers in the Pittsburgh Public Schools. PUMP produces a new algebra curriculum that is consistent with the recommendations of the NCTM.

Headed by Kenneth R. Koedinger, PUMP creates an intelligent tutoring system called PAT--the PUMP Algebra Tutor, or Practical Algebra Tutor--for use with the new curriculum.

• Professor Kenneth Koedinger on PUMP (03m:04s)

In the 93-94 school year, the Carnegie Mellon researchers extend their Algebra I course two more schools for a total of three Pittsburgh Public High Schools (Langley, Brashear, and Carrick). Based on the new PUMP curriculum, the course is set up to serve as a large-scale classroom experiment. The experiment will determine whether the PUMP curriculum and PAT as a whole are more effective than the traditional curriculum without an intelligent tutoring system.

The Algebra I course leads to 'large and consistent' gains on the NCTM standards-oriented assessments (approximately 100% or double improvement over control subjects) and 'moderate and statistically reliable' gains on the standardized assessments (~15% improvement)(Corbett, Koedinger, and Hadley 2002). The results are replicated in 1994-1995 with two more high schools.

• Professor Kenneth Koedinger on Algebra I evaluation (02m:58s)

At Carnegie Mellon, Dr. Steven Ritter begins work on pSAT, the Problem Situation Authoring Tool, an early user-friendly interface for authoring and encoding problems. Particularly useful for encoding word problems, pSAT allows a problem author to enter problem text along with a computer-understandable representation of the problem. The author then verifies the software's encoding of the problem, and saves it. In creating the problem representation, pSat removes the need for natural language parsing at runtime.

Later with an interface in Java, pSAT still runs in 2005. Problem authors at Carnegie Learning use pSAT to work on problems for their new 'Bridge to Algebra' software, an intervention product for middle school students.

The Carnegie Mellon researchers offer their cognitive tutor to high schools outside the Pittsburgh region. Participating schools include four Department of Defense Education Activity (DoDEA) schools in Europe and a third college. By the end of 1997, the total number of sites is 24.

• Professor Kenneth Koedinger on early efforts to commercialize Algebra I(01m:36s)

Steven Ritter and Kenneth R. Koedinger publish their paper 'An Architecture For Plug-In Tutor Agents', which establishes architectural principles for adding tutoring to a program.

In a joint effort with the University of Pittsburgh, the Carnegie Mellon researchers receive a major National Science Foundation grant to form a research center--this becomes known as the Center for Interdisciplinary Research on Constructive Learning Environments (CIRCLE)--to study human tutoring and to develop a more effective next generation of computer-based tutors.

The Cognitive Tutor Algebra I curriculum receives accolades from the US Department of Education, which gives it the highest "exemplary" designation awarded to only five curricula.

With the help of recently founded Carnegie Learning, Inc., the CMU researchers begin developing full Cognitive Tutor courses for middle school mathematics. Albert Corbett leads development for 7th and 8th grade and pre-algebra courses; Kenneth Koedinger leads the 6th grade course development.

Cognitive Tutor Algebra I is in use in 150 public and private schools, in 14 different states. More than 300 sites are predicted for the 2000-2001 academic year.

Carnegie Mellon researchers Vincent Aleven and Kenneth Koedinger publish the results of an experiment on the effects of self-explanation on learning in a computer-based Cognitive Tutor. They discover that supporting self-explanation in a Cognitive Tutor during problem solving practice leads to more effective learning that avoids 'shallow heuristics' and promotes 'deeper understanding' of material. The researchers describe the greater understanding in terms of 'more integrated visual and verbal declarative knowledge, used more reflectively, and less shallow procedural knowledge.'

The study is one of the first to compare a tutor that reinforces self-explanation with one that does not. The results of the in vivo experiment are published in the journal Cognitive Science.

The success of the study prompts Carnegie Learning, Inc. to include support for self-explanation in the current version of the Cognitive Tutor for geometry problem-solving.

Carnegie Mellon researchers start work on the Cognitive Tutor Authoring Tools (CTAT), a suite of authoring tools that aims to make tutor development more affordable by leveraging human-computer interaction (HCI), machine learning, and data mining techniques. In addition, the software will facilitate cognitive modeling for experts and enable cognitive modeling for novices in cognitive science.

The Cognitive Tutor Algebra I course is in use in roughly 2000 schools across the United States. The data show that students in the Cognitive Tutor Algebra I course score twice as high on end-of-course open-ended problem-solving tests, and 15% higher on objective tests as students enrolled in a traditional Algebra course. Most participating schools are urban or rural high schools. The researchers estimate that a half million students who have used the tutor, for a total usage time of 20 million hours.

In its second project year, the Genetics Cognitive Tutor project completes evaluations of their six tutor units at four pilot schools. The Project is awarded grants from both the National Science Foundation and the Howard Hughes Medical Institute, funding that enables it to develop tutor curriculum for a full genetics course. A total of 12 lessons are completed.

• Professor Kenneth Koedinger on textbooks of the future (10m:11s)

Building on its history of user interface innovation, Carnegie Learning releases Bridge to Algebra, an intervention product for middle school students that prominently features usability constraints and novel interaction mechanisms. The product was piloted in ~100 schools in 2005.

Carnegie Learning embarks on a project to create tools for teachers to build curricula. The project is funded by a subaward with "Science Mission to Planet Earth (SMPE): IT-Integrated Coastal Education" project, a grant to Southern University from the National Science Foundation's 'Information Technology Experiences for Students and Teachers' (ITEST) program.