Two criteria for the automatic encoding of learning, instructional manipulation, and stimulus characteristics were studied in subjects who judged the frequency of occurrence of words, letters, and nonwords. In Experiment 1, six word lists were constructed with varying frequency of alphabet letters. A variety of instructions were presented (whether to study word frequency or letter frequency). Some subjects were administered the expected task, and others were surprised with a different test. Results confirmed that subjects were more accurate when they were told to attend to letter frequency (the intentional condition) than word frequency (the incidental condition). In the word frequency task, subjects who were instructed to remember word frequency performed better than those instructed to remember letter frequency, the distractor. Experiment 2 varied the meaningfulness of letter strings (some were words and some were not) and high versus low probability of occurrence. In general, judgment of frequency increased as did actual frequency. As frequency increased, so did the differences in judgments between meaningful versus nonsense words, and between high versus low probability words. It was concluded that frequency information was processed automatically, but varied according to the type of material presented. (GDC)