The frequency of judgment effect is a special case of Response Mode effect in human covariation and causal learning. Judgment adjustment -to DP-, depends on the trial type preceding that judgment, but that effect is restricted to situations in which participants are asked to make their judgments with a high frequency. Two experiments further demonstrated the reliability and the generality of this effect in positive and negative causal learning tasks. Experiment 1 yielded similar judgment frequency effects with a higher positive contingency (DP= 0.71) and a larger block size (n=16) than in previous studies. Experiment 2 showed that judgment frequency also modulates the detection of negative contingency (DP= -0.5), as far as judgment accuracy was shown to be a function of the type of trial just preceding that judgment in the high frequency group. Associative and statistical models of covariation learning cannot easily explain these results without incorporating relevant post-hoc assumptions. These findings add new-evidence to the growing body of data showing that human causal learning depends on the action of several mechanisms, as proposed by the Belief Revision Model.