Cognitive System Components
Composed of working memory, long-term memory, and the cognitive processor, it is responsible for processing perceived information and deciding how to act upon it.
Motor System Cycle Time (TM)
The time required to issue a motor command, which is approximately 70ms but can range from 30-100ms depending on the task.
Pen Stroke Correction Time
An analysis of pen strokes indicates that a single correction takes 250ms, which is the sum of 100ms (perceptual) + 70ms (cognitive) + 70ms (motor).
Time Requirement for Real-Time Control
For a user to perceive that they are controlling a system in real time, the system’s response time must be less than 0.01 seconds.
Time Requirement for Cause-Effect Perception
For a user to perceive a cause-effect relationship, such as clicking a button, feedback must be provided within 0.1 seconds.
Humans as Information Processors
The view in cognitive science where humans are understood in terms of three stages: perception (gaining information), cognition (processing information), and motor action (outputting information
Cognition (in Information Processing)
The stage where we process information based on existing knowledge, gain new knowledge, and make decisions.
Motor Action
The ‘information output’ stage where humans interact with the world through activities like speaking, gesturing, writing, drawing, or navigating.
Model Human Processor (MHP)
A model introduced in a 1983 book to describe human performance in HCI, bridging Psychology and Computer Science.
CMN Model
An alternative name for the Model Human Processor (MHP), named after the model’s authors.
Bloch’s Law
A principle of the perceptual system where multiple short, similar stimuli occurring in the same cycle are integrated and perceived as a single stimulus of greater intensity. It is represented by the formula $R = I \times t$.
Uncertainty Principle (Cognitive Processing)
The principle that the decision time of the cognitive processor increases with the level of uncertainty about the judgment to be made, as this requires more cognitive cycles.
Influences on Perceptual Coding
The order of coding is influenced by attention (what we focus on), while the type of coding is influenced by Gestalt perception of patterns and triggered associations
MHP as a Model of Processing
The Model Human Processor is a model of rational information processing that can be used to predict performance, but it does not account for emotion.
Human as Information Processor
A viewpoint in HCI that models humans as systems that process information, with inputs (eyes, ears), outputs (arm-hand-finger), and a brain containing processors and memories.
Perceived System Responsiveness
Interactive systems are perceived as responsive when they comply with human time requirements at different scales of action, from low-level perception to high-level tasks.
Model Human Processor (MHP)
A simplified model of a computer user, comprising eyes and ears for input, an arm-hand-finger for output, and a brain with processors and memories.
Goal of Modelling Human Performance
To enable a rough prediction of the time it takes for a human to process information, analogous to predicting computer performance.
Analogy for Human Performance Models
The idea is similar to computer science models that describe a computer’s performance based on its processors, clock speed, memory, and capacity.
Performance Parameters (MHP)
The idea is similar to computer science models that describe a computer’s performance based on its processors, clock speed, memory, and capacity
Performance Parameters (MHP)
In the Model Human Processor, the brain’s processors and memories each have specific performance parameters and connections that influence processing time.
What is the primary function of the Perceptual System within the Model Human Processor?
Transforming external events into a form that the cognitive system can process.
According to the presentation, in what year was the book that introduced the Model Human Processor (MHP) published?
1983
Which statement accurately describes the processing nature of the cognitive processor’s recognize-act cycle?
Recognition is highly parallel, but Acting is serial.
