Inlaw, the parol evidence rule refers to one of the pillars in commonlaw that bars any party from presenting or introducing extrinsicevidence meant either to open up an ambiguity or present aclarification in contract cases that are written. Under normalcircumstances the contract appears to be whole. Various argumentshave been put forward questioning the admissibility of the parolevidence. However, there is no common agreed criterion on thehandling of the evidence. The parties that support the parol evidenceinsist that the agreement between the various parties is sandwichedby the contract in to the written document. As a result, no moreother evidence should be included in the case determination otherthan the written contract interpretation. Moreover the parties insistthat materials written prior to the signing of the contract should beexcluded as evidence in the determination stage. Furthermore, itmakes legal sense to exclude materials that are not written on thecontract drafted by the legal representatives of both parties.
However,in cases of contracts that are partially integrated it would beimportant to present such evidence to the jury for consideration.This would help resolve ambiguities and also aid in establishingdefenses for the contract. In cases of usage of draft contract theparol evidence rule is ignore since the draft is not the finalcontract. In this eventuality, the parties are encouraged to presentthe evidence to the jury to aid in the case determination. However,the absence of the merger clause may lead to declaration of acontract as not the final copy hence creating a loop whole for theintroduction of evidence prior to contract being signed by bothparties. The advantage of the eliminating the parol evidence would bethe increase in the information provided to the jury for therendering of an interpretation judgment. Furthermore, the jury wouldbe able to go to the root cause of the disagreement. However, theinclusion of the parol evidence would disadvantage one party atexpense through information elimination and discounting.