Our Prime Brokerage Web site was complicated but the didi redesign made it both simpler and clearer. The didi approach made our highly-functional Client-Access Reporting System much easier by applying unique didi information-object technology.

And the paper-prototype design process we learned from didi saved us uncountable development hours plus reduced business-side frustration.

—Perry Metviner, MD of Lehman Brothers Prime Brokerage Development

The Cognitive Engineering Design Methodology

The process we use to apply Cognitive Engineering, honed over decades of research and real-world projects.

Online Class

The online class is five sessions long. It’s a compressed, updated version of the Columbia University Department of Computer Science COMS 6998-005 graduate seminar class, the result of a 2003 appointment of W. Bradford Paley as an Adjunct Associate Professor to teach his own interaction design methodology, giving graduate students an alternative to conventional user interface design processes.

Click here to enroll or email us with questions.

Certification: A certificate is generated; it confirms “[name] has attended a class in the Cognitive Engineering Design Methodology.” If a student excels by completing all sessions and turning in exercises that demonstrate they’ve mastered the material well enough to apply it to real-world projects their certificate will read “[name] has mastered the fundamentals of the Cognitive Engineering Design Methodology.” (Approximately one third of the Columbia students reach that level.)

Format: There is an introductory overview and four primary class sessions, each 2.5 hours long. Professor Paley is available in common on-line “office hours” on consecutive days to be arranged as classes fill. Exercises must be delivered to didi within three days of each class. Certificates or additional one-on-one spot-retraining are returned within three weeks.

The class is always taught by Professor Paley, and he himself is present during online office hours. Here’s a short bio. Grading for certification may be done by colleagues with expertise in the methodology.

Class Session Synopses

One: Extracting the Expert’s Mental Model

Attendees learn to work with domain experts, unambiguously capturing what’s in their minds as they do tasks. CEDM structured outlines rigorously break down expert workflows into goals, tasks, and steps; separately capturing task-related cognitive entities, contexts, states, and transitions.

Two: Paper & Pencil: The Ultimate Rapid Prototyping Tools

We teach how to use standard office supplies fluently, to facilitate conversations with experts that results in “Schematics” which capture everything necessary to accomplish a task, and can be verified to do so. Schematics often result in innovation since they reveal how tasks are organized inside the expert’s mind. They leave an interface’s final layout to an explicit cost/benefit budgeting stage.

Three: StepAffordance Maps; Information Layering, Managing Attention

Attendees learn to map each mental step in every task to the available affordances, creating a “Release Candidate.” This mapping provides a rational basis for what to prioritize or cut—or can quantitatively justify a bigger budget. The supplied CEDM Feature Evaluation Tool embodies economic techniques to approximate even hard-to-value features. This lets all stakeholders balance concrete, real-world, ongoing benefits (like time saved and reduced risk) against one-time development costs.

Four: Paper Prototyping, 100:1 Savings Finding/Fixing Bugs

We teach how to test Release Candidates, completely and in realistic situations before spec-writing begins, by simulating the system with paper “screens.” This engages the actual mental task steps the expert does in the real world, unlike a PowerPoint walk-through. Students learn to identify exactly what’s wrong and often fix it in a single sessiona hundred times faster, assuming design takes 1/10th the time spec-writing does, and specs take 1/10th the time of coding.

> Class Topic Details

On-Site Introductory Lecture (suspended for now)

The lecture is a one- or two-hour lecture introduction to the CEDM.

Format: The lecture is done at a client’s site; it’s a two-hour lecture and includes a 15-minute break that is also time for informal questions.

Material Covered: The entire contents of the class are discussed in reverse order: backwards with respect to how they are applied in practice. We start with easily understood visual layering effects and build to more abstract ideas concerning experts’ mental models. The presentation is intentionally quick; it serves to lay out and integrate the dozen or more disciplines that provide the underpinnings of the methodology—from Typography to Vision’s object recognition, from Attention and Memory to Psycholinguistics’ jargon development.

Staff: The lecture is always presented by Professor Paley. Here’s a short bio.

Case Study: BIDS Trading

In the words of one of the founders, how Cognitive Engineering changed the venture. A little bit of trading venue history, with before and after images.

Case Study (Web page on this site)

White Paper

Rather dense, but a concisely comprehensive case study of applying the methodology to optimize trading desk operations.


These books provided the foundations of the methodology.