A medical school wants to train technicians to recognize the locations of canacer from magnetic resonance images. How can principles of signal detection be used to track the progress of the trainees? Solution signal detections are very much important in many ways for example in a medical school to track the progress of the trainees signal detections are very useful. Since technicians recognize the locations of cancer from magnetic resonance images if to check the progress of these technicians then signal detections which have one dimension characteristic for differentiate the loudness and brightness and to differentiate various things. These signal detections will monitor the behaviour of technicians and check there progress regularly..