What is the test for determining whether a witness has privileged information?

In conducting this inquiry, the court (or arbitrator) considers the witness's claim of privilege along with the interests of the plaintiff, who is entitled to "an expeditious and fair resolution of their civil claims," and the court's interest in "fairly and expeditiously disposing of civil cases, and in efficiently utilizing judicial resources." (Fuller v. Superior Court (2001) 87 Cal.App.4th 299, 306.) "[C]ourts are guided by the strong principle that any elapsed time other than that reasonably required for pleadings and discovery 'is unacceptable and should be eliminated.' [Citation.] Courts must control the pace of litigation, reduce delay, and maintain a current docket so as to enable the just, expeditious, and efficient resolution of cases." (Id. at pp. 306-307.)