field. As in the original paradigm developed by Miller, participants were asked to memorize a list of letter strings which were created from an artificial grammar rule model. It was only during the test phase that participants were told that there was a set of rules behind the letter sequences they memorized. They were then instructed to categorize new letter strings based on the same set of rules which they had not previously been exposed to. They classified new letter strings as "grammatical" (constructed from the grammar rule), vs. "randomly constructed" sequences. If subjects correctly sorted the new strings above chance level, it could be inferred that subjects had acquired the grammatical rule structure without any explicit instruction of the rules. Reber found that participants sorted out new strings above chance level. While they reported using strategies during the sorting task, they could not actually verbalize those strategies. Subjects could identify which strings were grammatically correct but could not identify the rules that composed grammatical strings. This research was replicated and expanded upon by many others. The conclusions of most of these studies were congruent with Reber's hypothesis: the implicit learning process was done with no intentional learning strategies. These studies also identified common characteristics for the implicitly acquired knowledge: Abstract representation for the set of rules. Unconscious strategies that can be tested with performance. The modern paradigm The modern AGL paradigm can be used to investigate explicit and implicit learning, although it is most often used to test implicit learning. In a typical AGL experiment, participants are required to memorize strings of letters previously generated by a specific grammar. The length of the strings usually ranges from 2-9 letters per string. An example of such a grammar is shown in figure 1. Figure 1: Example of an artificial grammar rule Ruleful strings:VXVS, TPTXVS Unruleful strings:VXXXS, TPTPS In order to compose a grammatically "ruleful" string of letters, according to the predetermined grammar rule, a subject must follow the rules for the pairing of letters as represented in the model (figure 1). When observing a violation of the grammatical rule system that composes the string, it is considered an "unruleful" or randomly constructed string. In the case of a standard AGL implicit learning task, subjects are not told that the strings are based on a specific grammar. Instead, they are simply given the task to memorize the letter strings for a