With construction being such a complex assembly process, using many independent agents, it is not surprising that differences sometimes arise. When they do, there are two main ways of attempting to deal with them, internally by direct negotiation between the disputants, perhaps by reference to an involved, but separate third party, or externally by reference to an independent third party. Direct negotiation is always available to the parties, but for many building contracts there is also a contract administrator involved in designing the building and certifying payment and satisfaction with the work. The act of certifying itself demands a degree of impartiality and both the Employer and Contractor can look to the certifier to be impartial. There is, however, a key difference between certification and dispute resolution, in that for the former a dispute has not expressly arisen – the certifier is simply giving a fair and objective opinion on the matter in question. Negotiations may have preceded the issue of a certificate and a certificate may later be corrected if it proves wrong, but if it is still not satisfactory, then a further method has to be found to achieve a resolution.