  Software testing is presented as a so-called theme within which different
authors and groups have defined different subjects each of these subjects
having a different focus on testing. A uniform concept of software testing is
non-existent and the space of possible coherent perspectives on software
testing, each fitting within the theme, is viewed as being spanned by five
dimensions, each dimension representing two opposite views with a variety of
intermediate views in between.
  Instruction sequences are used as a simple theoretical conceptualization of
computer programs. A theory of instruction sequence testing may serve as a
model for a theory of software testing. Instruction sequences testing is
considered a new topic for which definitions may be freely contemplated without
being restricted by existing views on software testing.
  The problem of developing a theory of instruction sequence testing is posed.
A survey is given of motivations and scenarios for developing a theory of
instruction sequence testing.
