correlate the ambient modification with feedback information such as consistency and quality of recorded sleep cycles and or energy level and performance during the following day in this manner a user can determine in a personalized manner what ambient modification if any is most suitable discussion of provision of a schedule 110 to the user will be discussed below in connection with example 2 one mode of operation of the method of fig1 is to awaken the user after a certain number of sleep cycles have been completed various modifications and elaborations of this mode of operation can be provided by making use of optional inputs 114 on fig1 and by appropriately modifying decision algorithm 106 fig2 is a flow diagram showing various exemplary optional inputs 114 to decision algorithm 106 of fig1 for example a nominal awakening time 212 can be provided to decision algorithm 106 and the user can be awakened either at the nominal awakening time or at the completion of a set number of sleep cycles whichever occurs earlier user preferences 208 such as desired number of sleep cycles and preferred phase of a sleep cycle to be awakened in can be included as optional inputs to decision algorithm 106 preferences 208 can include parameters and or rule based information for resolving possibly conflicting directives for example the desired number of sleep cycles can conflict with the nominal awakening time and this conflict can be.