Probabilistic convergence, also called convergence in probability, of a sequence of random variables to a random variable
means that, for every
,
The notation
is commonly used. If
converges almost surely,
then it converges in probability, and convergence in probability implies distributional
convergence. Neither converse holds without additional hypotheses.
If
converges in probability to a constant, then it also
converges in distribution to that constant. The weak
law of large numbers is a basic example of convergence in probability.