Incremental Transformations:

add target attributes (weight 1)

drop target attributes (weight 1)

replace sources (weight 3)

add a conditional clause (weight 2)

If the query distance between q₁ and q_n is below a threshold t, it is an Incremental Query Morphing Pair.

Non-Incremental Transformations:

Completely rewrite the query

If the query distance between q₁ and q_n is above a threshold t, it is a Non-incremental Query Morphing Pair.

Examples from distance eduction