Pareto’s Principle: 80/20

A high percentage of effects in any large system are caused by a low percentage of variables.

E.g. 80% of Web traffic is caused by 20% of Web sites

Aka Juran’s principle, Vital few, Trivial Many Rule

Based on Vilfredo Pareto (economist); seminal work: Quality Control Handbook (1951) by Joseph M Juran (ed.)


Tacit knowledge – Explicit knowledge

  • Explicit knowledge is relatively easy to capture and store in databases and documents. It is shared with a high degree of accuracy. Explicit knowledge can be either structured or unstructured:
  • Structured – Individual elements are organized in a particular way or schema for future retrieval. It includes documents, databases, and spreadsheets.
  • Unstructured – The information contained is not referenced for retrieval. Examples include e-mail messages, images, training courses, and audio and video selections.
  • Tacit knowledge is knowledge that people carry in their minds and is, therefore, difficult to access. Often, people are not aware of the knowledge they possess or how it can be valuable to others. Tacit knowledge is considered more valuable because it provides context for people, places, ideas, and experiences. Effective transfer of tacit knowledge generally requires extensive personal contact and trust.


Tacit Knowledge (Polanyi)

The concept […] comes from scientist and philosopher Michael Polanyi […] to name a form of knowledge that is apparently wholly or partly inexplicable.

Tacit knowledge is not easily shared. One of Polanyi’s famous aphorisms is: “We know more than we can tell.” Tacit knowledge consists often of habits and culture that we do not recognize in ourselves. In the field of knowledge management the concept of tacit knowledge refers to a knowledge which is only known by an individual and that is difficult to communicate to the rest of an organization. Knowledge that is easy to communicate is called explicit knowledge. […] Tacit knowledge is considered more valuable because it provides context for people, places, ideas, and experiences. Effective transfer of tacit knowledge generally requires extensive personal contact and trust. The process of transforming tacit knowledge into explicit knowledge is known as codification or articulation.

Sourced from Wikipedia, paraphrased by twobenches

Different Types of IA/UX Research

  1. Protocol-generation techniques
    – include various types of interviews (unstructured, semi-structured and structured), reporting techniques (such as self-report and shadowing) and observational techniques
  2. Protocol analysis techniques
    – are used with transcripts of interviews or other text-based information to identify various types of knowledge, such as goals, decisions, relationships and attributes. This acts as a bridge between the use of protocol-based techniques and knowledge modelling techniques.
  3. Hierarchy-generation techniques
    – such as laddering are used to build taxonomies or other hierarchical structures such as goal trees and decision networks.
  4. Matrix-based techniques
    – involve the construction of grids indicating such things as problems encountered against possible solutions. Important types include the use of frames for representing the properties of concepts and the repertory grid technique used to elicit, rate, analyse and categorise the properties of concepts
  5. Sorting techniques
    – are used for capturing the way people compare and order concepts, and can lead to the revelation of knowledge about classes, properties and priorities.
  6. Limited-information and constrained-processing tasks
    – are techniques that either limit the time and/or information available to the expert when performing tasks. For instance, the twenty-questions technique provides an efficient way of accessing the key information in a domain in a prioritised order
  7. Diagram-based techniques
    – include the generation and use of concept maps, state transition networks, event diagrams and process maps. The use of these is particularly important in capturing the “what, how, when, who and why” of tasks and events.

Sean Bechhofer: Knowledge Elicitation (PDF)

Triadic Knowledge Elicitation: 3 Card Trick

• Select 3 cards at random
• Identify which 2 cards are the most similar?
– Why?
– What makes them different from the third card?
• Helps to determine the characteristics of our classes
• Picking 3 cards forces us into identifying differences between them
– There will always be two that are “closer” together
– Although which two cards that is may differ depending on your

Sean Bechhofer: Knowledge Elicitation (PDF)