Fringes of Knowledge States

Computes the fringe of a knowledge state.

kfringe(kst, state)

  kfringe_inner(kst, state)

  kfringe_outer(kst, state)

Arguments

kst	An R object of class kstructure.
state	An R object of class set.

Details

The fringe determines the symmetric difference between a given knowledge state and its neighbouring states. It is divided into inner and outer fringe. The inner fringe contains the fringe items which are element of the knowledge state. They have probably been recently learned. The outer fringe contains those fringe items which are noe element of the knowledge state. For these items, all prerequisites are fulfilled, i.e. the learner is ready to learn them now.

Value

A set contining the fringe of state. If state is NULL then a list containing the fringes of all knowledge states is returned.

References

Doignon, J.-P., Falmagne, J.-C. (1999) Knowledge Spaces. Heidelberg: Springer Verlag.

See also

kneighbourhood, kstructure, set

Examples

kst <- kstructure(set(set(), set("c"), set("a","b"), set("b","c"), 
   set("c","d"), set("d","e"), set("a","b","c"), set("b","c","d"), 
   set("c","d","e"), set("a","b","c","d"), set("a","b","d","e"), 
   set("b","c","d","e"), set("a","b","c","d","e")))

# fringe
kfringe(kst, set("c","d","e"))
#> {"b", "c", "e"}