Abstract: A system for suppressing sound from a flame comprises a detector for detecting a first signal which emanates from the flame. A photo sensor rapidly detects the noise from the flame. The first signal is inverted to produce a second signal. The second signal is applied to the flame for cancelling the sound produced by the flame. Preferably, an electric arc is produced between a cathode positioned in the flame and an anode positioned around the flame. The electric arc is modulated by the second signal.

Abstract: A system for assessing the diagnostic reasoning ability of learners engaged in a field of study employs a coded situation test and utilizes a computerized process for grading examinations taken by the learners and for rating their capacity for diagnostic reasoning. The computerized diagnostic reasoning evaluation instrument embodies storage in a test file of the situation test description which describes, illustratively in narrative form, a plurality of problems associated with the situation test employing a plurality of phrases. Each phrase has associated therewith a respective phrase identification symbol which is used by the examinee to record answers to the examination. In a nursing embodiment of the invention, each learner selects from a listing of possible problems. Those problems which are considered by the learner to be significant and present in the situation test are then identified by storing their respectively associated code symbol.