1. A computerized method for evaluating a patent portfolio, comprising patent documents, by one or more experts, the method comprising: performing by a processor of a computing device the following steps: (a) determining a bias of each said expert by comparing results of evaluation of at least one test patent document performed by each said expert with a predetermined evaluation of said test patent document; and (b) evaluating the patent documents from the patent portfolio by said experts according to an evaluation method, including bias correcting the evaluation method for each said expert so that to compensate for the bias of each said expert; wherein: the step (b) further comprises evaluating a patent document from the patent portfolio according to an evaluation method, which processes a number of patent indices, characterizing different aspects of the patent document, into a Patent Quality index (PQ), characterizing value of the patent document, according to a non-linear function of said patent indices; the non-linear function is characterized by a parameter of non-linearity, corresponding to a bias of an expert and selected so that to compensate for the bias of the expert; the step (b) further comprises selecting the non-linear function, which is continuous, monotonously increasing or decreasing, bounded on the interval of variations of patent indices, and processes the patent indices into the PQ as follows: when a value of any patent index tends substantially to its minimal value, then the PQ also tends substantially to its minimal value for the increasing function, and to its maximal value for the decreasing function.
2. The method as described in claim 1 , wherein the step (a) further comprises determining the bias of each said expert “B” as an average bias <B> across different test patent documents evaluated by each said expert.