This paper presents a method of ‘ground reactivity integration’ using a modified linear shrinkage (MLS) test. This method was first developed in the 1970s and updated in 1993 by Universal Soil Laboratories Pty Ltd (USL). In 1999 it was re-examined and further modified with the introduction of suction sign posts. The results were compared with the shrink/swell (S/S) test method described in AS 2870 and AS 1289. A typical ‘family of curves’ of strain/suction relationships and shrink/swell indices (Iss) were also compared to soil geology and climate in Victoria.