If after extensive research, the expected observations predicted by a theory fail to materialize:

the theory is confirmed
the theory is probably false
the theory should be abandoned or modified
the theory formulated through experimentation should never be retracted

Question

If after extensive research, the expected observations predicted by a theory fail to materialize:

the theory is confirmed
the theory is probably false
the theory should be abandoned or modified
the theory formulated through experimentation should never be retracted

koikkara · Answer

Since, the expected observations predicted by a theory fail to materialize, ofcourse the theory should be abandoned or modified. @Maddiem