STR returns the string representation of the value.
WIMS will make the cell type Text (most WIMS formulas return numeric values, therefore cells are set to Num when formulas are entered, the STR function overrides this) if STR is the first part of the function. See Examples.
=STR(B2) Returns "Rocky Creek" - Cell B2 has the text "Rocky Creek"
=STR(IF(VAL(C1)>60,"PASS","FAIL")) Returns PASS if C1 is greater than 60. If STR is not used cell would be made a Num cell and would always return a blank result.
=VAL(IF(STR(D4)="PASS",1,0)) - returns 1 if D4 = "PASS" and the cell type will be numeric. Notice the VAL function overrides the STR (which tries to make the cell type text) because VAL is the outer most function.