Abstract: Summa?y.-The present study tests the acquisition-strategy hypothesis of serial learning, which attributes the serial-position effect to consistent orders of item acquisition among individual Ss, and over-all learning difficulty in part to the ease of establishing an order of acquisition. As predicted, lists of CVC trigrams which were organized in terms of associative values to facilitate a temporal beginning-to-end strategy of acquisition were learned faster than unorganized lists or lists organized from end to beginning. Also as predicted, an unorganized array of heterogeneous trigrams produced more errors and less regularity of the serial-position curves than, a homogeneous series. Results thus supported the strategy hypothesis of serial learning. The classical serial-position effect reflects different rates of learning due to the relative position of items, because ordinarily the items themselves are about equally difficult. Several theories attribute this effect to Ss' strategies of learning the items in a consistent order (e.g., Feigenbaum & Simon, 1962; Harcum & Coppage, 1965; Jensen, 1962a). According to such theories, S typically learns the temporally first item first, and then adds adjacent items to this "anchor" in both forward and backward directions. For a series of heterogeneous items the extra competition between potential strategies of ordering should inhibit learning if the intrinsic differences in learnability are haphazardly atracged. Buc, on the contrary, if the items are so ordered that intrinsic differences in difficulty support a coherent (usually beginning-toend) organization, then the learning should be faster for heterogeneous items. Learning has been found to 5e facilitated by addition of internal associative structure. For example, learnicg and recall are improved when the items can be placed in the context of a nerrative sentence or story (e.g., Bower & Clark, 1969; Guilford, 1927; Levin & Rohwer, 1968; Simpson, 1967). Similarly, structure produced by morphology and syntax (O'Connell, Stubbs, & Theby, 1968) and by meaningful internal clustering (Weingarcner, 1963) also facilitates serial learning. Miller (1965 ) found items grouped into categories were learned faster than the same items arranged in haphazard order. Subjective bases of organization also aid serial Learning. Gardner, Nappe, and Wallace (1968) required each S first to place 15 words in a sequence that would be, for him, easiest to learn by serial anticipation. Later S learned his own list and also a list similarly ordered by someone else, and also a randomly ordered