From Hodczak v. Latrobe Spec. Steel Co., 2010 U.S. Dist. LEXIS 21267 (W.D. Pa. Mar. 9, 2010):

The Federal Magistrates Act provides two separate standards for judicial review of a magistrate judge's decision: (i) "de novo" for magistrate resolution of dispositive matters, see 28 U.S.C. § 636(b)(1)(B)-(C), and (2) and (ii) "clearly erroneous or contrary to law" for magistrate resolution of nondispositive matters. See 28 U.S.C. § 636(b)(1)(A); accord Fed. R. Civ. P. 72(a), (b); Local Civil Rule 72.1.3; see also Cipollone v. Liggett Group, Inc., 875 F.2d 1108, 1113 (3d Cir. 1986), cert. denied, 484 U.S. 976 (1987). A magistrate judge's decision to deny a request for a motion to compel discovery is a nondispositive matter that must be reviewed by the district court under a clearly erroneous standard.

A finding is "clearly erroneous" when, "although there is evidence to support it, the reviewing court on the entire evidence is left with the definite and firm conviction that a mistake has been committed." Anderson v. City of Bessemer, 470 U.S. 564, 573 (1985); Republic of Philippines v. Westinghouse Elec. Corp., 132 F.R.D. 384, 387 (D.N.J.1990) (quoting United States v. United States Gypsum Co. , 333 U.S. 364, 395 (1948)).

Under this standard, a reviewing court will not reverse the magistrate judge's determination even if the court might have decided the matter differently. ***

"Where a magistrate judge is authorized to exercise his or her discretion, the decision will be reversed only for an abuse of that discretion." *** The deferential standard is particularly appropriate in the case where the magistrate judge has managed the case from the outset and developed a thorough knowledge of the proceedings. Id. at 127. Such is the case here.

In this case, because there is no issue of law in the dispute, this Court will review the decision of Chief Magistrate Judge Hay under an abuse of discretion standard.