Knowledge Elicitation Techniques

* Interviewing
* Protocol Analysis
* Multidimensional Scaling
* Card Sorting

INTERVIEWING

- Used to identify the overall structure of the experts knowledge domain.
- Two approaches to interviewing may be used:

     * Structured Interviews-specific probing
       questions are asked ( scope  of  the questions
       are usually identified in a preliminary interview
       with the expert).

     * Unstructured Interviews-expert is asked
       to provide all information regarding the domain,
       without specific elaboration of detail.

Note:Unstructured interviews can be used as a preliminary interview to the structured approach.

PROTOCOL ANALYSIS

- Expert is asked to "think aloud"; this is then recorded in some way.
- There are two forms of protocol analysis;

     1)Expert verbalizes every thought and action
       while solving a problem. This verbal ism is 
       recorded  and then transferred  to script.
       This method is termed  concurrent protocol
       because the information is obtained at the 
       same time the expert solves the problem.
           
     2)Expert is  video-taped while the problem is
       being solved.The video is then shown to the
       expert, who is asked to explain what he was
       thinking and doing . The  method is  termed
       retrospective protocol and is very useful to
       extract information which is largely  tacit 
       and not easy to verbalize.

- The two protocol techniques when applied together, may provide precise information concerning how a problem is tackled.

MULTIDIMENSIONAL SCALING

- A technique to elicit experience and relationships between objects from the view of an expert.
- Primarily used when there are a number of closely-related concepts and no specialized vocabulary to express subtle distinctions and relationships.
- Technique involves visually representing the psychological similarities between objects or experiences as points on a scatter graph. Objects which are psychologically dissimilar are shown far apart, the distance between them can be analyzed to interpret the underlying dimensions as to why these objects have been judged relative to one another.

CARD SORTING

- Easy to implement
- Involves writing the names of objects, experiences, or rules in the expert's domain onto individual cards.
- Three methods can be implemented:

         * Group Separation Tasks
         * Group Creation Tasks
         * Triadic Comparisons

Group Separation Tasks

- Successive grouping of cards to an underlying condition.
- Expert is asked to group cards into two, which are then named. The cards are shuffled and then the whole procedure is applied for three, four and more groupings.
- Example: The Number of 15 models of cars may be grouped into two categories named "foreign" and "domestic", then re-sorted into three categories; "sedan" , "hatchback", and "sports"; then re-sorted into four categories; " expensive domestic", " less expensive domestic", " expensive foreign", "less expensive foreign". A hierarchy tree may be created expressing the group categories as levels within the hierarchy.

Card Sorting: Group Separation

Group Creation Tasks

- Opposite to the " Group Separation" in that groups are not made smaller but " built-up".
- Expert is asked to find a pair of cards from the set of cards that are most similar than any other pair.
- Example:Two car models made by the same manufacturer may distinguish the pair from other cards.
- Next, expert is asked to find next most similar pairing or to add another card to the original pair.
- This procedure continues until all the cards have been grouped.
- Names of groups , links between groups, or the reason why a card is placed in a group are important issues.

Triadic Comparisons

- Three cards are randomly selected from the set of cards and then presented to expert.
- Expert is asked to pure the cards into two groups.

   (a) One with two most similar cards,
   (b) Another group with the card which is least similar.

- Experts is then asked to try and name the way in which the groups differ.
- Example:Two cars may be foreign sports cars and the other may be a domestic sports car, although all three cars are sports cars.

CONCLUSION

Card Sorting techniques provide a means of achieving a more focused or systematic understanding of the classifications and relationships in the expert's domain.
(Rules and heuristics are identified from this.)

These are the notes of Dr.Mehmet Tolun and written by Mehmet Nuri Cankaya. If you have any questions about web page design send e-mail to:cankaya@rorqual.cc.metu.edu.tr.