The distinction between a question of law and a question of fact was comprehensively discussed in the case of Microsoft Corporation v. Maxicorp, Inc., [25]  thus:               The distinction between questions of law and questions of fact is settled.  A question of law exists when the doubt or difference centers on what the law is on a certain state of facts.  A question of fact exists if the doubt centers on the truth or falsity of the alleged facts.  Though this delineation seems simple, determining the true nature and extent of the distinction is sometimes problematic.  For example, it is incorrect to presume that all cases where the facts are not in dispute automatically involve purely questions of law.               There is a question of law if the issue raised is capable of being resolved without need of reviewing the probative value of the evidence.  The resolution of the issue must rest solely on what the law provides on the given set of circumstances.  Once it is clear that the issue invites a review of the evidence presented, the question posed is one of fact.  If the query requires a re-evaluation of the credibility of witnesses, or the existence or relevance of surrounding circumstances and their relation to each other, the issue in that query is factual.[26]                 In this case, the issues brought for our consideration calls for the re- examination of the evidence presented by the parties and the determination of whether the Labor Arbiter, the NLRC, and the Court of Appeals erred in their respective evaluation of the same.  This we cannot do without blurring the difference between a question of fact and a question of law – a significant distinction as far as the remedy of appeal by certiorari is concerned.             Furthermore, factual findings of administrative agencies that are affirmed by the Court of Appeals are conclusive on the parties and not reviewable by this Court.[27]  This is so because of the special knowledge and expertise gained by these quasi-judicial agencies from presiding over matters falling within their jurisdiction.[28]  So long as these factual findings are supported by substantial evidence, this Court will not disturb the same.[29]             As earlier stated, in this case, the Labor Arbiter, the NLRC, and the Court of Appeals are unanimous in their factual conclusions that Wallan Al Wallan is not an accredited principal of respondent Skills International and we sustain said findings.  As aptly observed by the NLRC –