  We derive analytical expressions for the correlation functions of the
electronic conductance fluctuations of an open quantum dot under several
conditions. Both the variation of energy and that of an external parameter such
as an applied perpendicular or parallel magnetic fields are considered in the
general case of partial openness.. These expressions are then used to obtain
the ensemble averaged density of maxima, a measure recently suggested to
contain invaluable information concerning the chaoticity of the system. The
correlation width is then calculated for the case of energy variation and a
significant deviation from the Weisskopf estimate is found in the case of two
terminals. The results are extended to more than two terminals. All our results
are analytical.The use of these results in other fields, such as nuclei, where
the system can only be studied through a variation of the energy, is then
discussed.
