  Continuous and pulsed quantum Zeno effects were observed using a $^{87}$Rb
Bose-Einstein condensate(BEC). Oscillations between two ground hyperfine states
of a magnetically trapped condensate, externally driven at a transition rate
$\omega_R$, were suppressed by destructively measuring the population in one of
the states with resonant light. The suppression of the transition rate in the
two level system was quantified for pulsed measurements with a time interval
$\delta t$ between pulses and continuous measurements with a scattering rate
$\gamma$. We observe that the continuous measurements exhibit the same
suppression in the transition rate as the pulsed measurements when
$\gamma\delta t=3.60(0.43)$, in agreement with the predicted value of 4.
Increasing the measurement rate suppressed the transition rate down to
$0.005\omega_R$.
