"definitive method" is a correct and usable phrase in written English.
You could use it to describe a method that is definite or certain, for example: "This is the definitive method for calculating the area of a triangle."
"The attempt at murder having failed, you decided on a more ruthless and definitive method of killing.
For measuring land area, he abandoned the use of hemp rope in favour of a more definitive method using lengths of bamboo joined with iron rings.
However, despite considerable research effort, a definitive method for evaluating the reliability of FIB systems had not been developed.
For numbers that can be entered reasonably into a computer -- say up to a few hundred digits -- a definitive method was found by young Indian computer scientists last year.
According to the Hungarian Scoring Tables, the definitive method of evaluating athletics performances, it is equivalent to a 2 01 58 marathon by a man.
Craig Osenberg, an ecology professor at the University of Florida who was not involved in either study, said there was no definitive method.
This is primarily due to a lack of definitive methods to analyse the strength and stiffness of the tank and frame.
One of the definitive methods to arrive at an optimum value of the selectivity and yield has been the addition of neutral salts to the ATPS [16].
There have been comprehensive studies centered on SVM [ 24, 25], but there have been no definitive methods in this type.
Having defined the copy number of some reference standard samples using definitive methods such as PFGE, these can be then used to calibrate and test further experiments.
Based on the results of this study we will design future studies for earlier diagnosis of TE using definitive methods like venography and future randomized controlled trial of prophylactic anticoagulant therapy in children with cancer.
