The introduction of the mini-computer into the dynamics test laboratory has made it possible to use several forms of multi-frequency excitation to speed up and simplify modal testing. These techniques have been described in the recent literature which has revealed that some of these forms of excitation are now used routinely in modal tests. A few of the earlier classical modal testing techniques have been upgraded and they are still in use. Therefore the test engineer has a wider choice of testing techniques and this could lead to difficulties in selecting the proper test method if several methods appear to be suitable. Thus published guidance for selecting proper modal test methods is needed. This information need might be met in any of the following ways. Modal testing techniques have matured to the point where a review of all of the available methods might be published. It should include, but not be limited to, a description of the various methods, their advantages and limitations and their suitability for modal tests of various types of hardware. More published comparisons of the results of modal te^.s, using a number of different test methods, would be useful, in addition to the obvious comparison of the modal parameters and the ability to isolate all significant modes, other comparisons should be made. These should include the ease of performing the test, the overall cost of testing, instrumentation requirements and the complexity of the data processing requirements. In 1976 a survey of modal testing practices was conducted. A number of factors were examined, such as the type of excitation, instrumentation, test article boundary and support conditions and many more. It is time to undertake a similar survey to see what changes in modal testing practices have occurred. Any or all of the above steps would be helpful in defining the state of the art of modal testing, but more importantly, they would provide guidance for selecting a testing technique, or techniques, that would be the most suitable for the job. This is important because use of the wrong test method could lead to confusing and/or meaningless results. R.H.V. f (^> crt. i£ :2i LITERATURE REVIEW:-' Vibration lltoratur« The monthly Literature Review, a subjective critique and summary of the literature, consists of two to four review articles each month, 3,000 to 4,000 words in length. The purpose of this section is to present a "digest" of literature over a period of three years. Planned by the Technical Editor, this section provides the DIGEST reader with up-to-date insights into current technology in more than 150 topic areas. Review articles inlcude technical information from articles, reports, and unpublished proceedings. Each article also contains a minor tutorial of the technical area under discussion, a survey and evaluation of the new literature, and recommendations. Review articles are written by experts in the shock and vibration field. This issue of the DIGEST contains an article about vibrations of conical shells. Professor C.H. Chang of t...