The work product doctrine protects from pretrial discovery witness statements and other documents gathered by an adversary's counsel in the course of preparation for possible litigation. The purpose of the work product doctrine is to preserve the privacy and independence of lawyers by denying unwarranted intrusions into their private files and mental processes. Prior to the 1970 amendments to the Federal Rules of Civil Procedure, courts applied two distinct tests when considering whether to allow pretrial discovery of documents and witness statements. One test required the party seeking discovery to show good cause why discovery should be allowed. The alternative test required the moving party to demonstrate either the necessity for the production of the work product materials or that denial of such discovery would unduly prejudice his case and cause hardship or injustice. Not only did the courts have difficulty distinguishing between the good cause test of Rule 34 and the necessity or undue hardship test, but the courts also were faced with the question of whether the work product privilege could be extended to work prepared by a non-attorney.