The effect of a broadband wave number(k)and frequency (&ohgr;) spectrumS(k,&ohgr;),on particle flux due to electrostatic fluctuations in a plasma is examined. Effect of the broadband spectrum on density-potential coherence is also calculated. Particle flux results are compared with a standard quasilinear transport estimate that has been used to interpret heavy ion beam probe and Langmuir probe measurements in fusion plasmas. Situations in which the quasilinear estimate is probably inaccurate are illustrated, including edge shear layer measurements and interior measurements from the TEXT tokamak. ©1997 American Institute of Physics.