The potential value and limitations of contrastive linguistic analysis (CLA) in pedagogical application are examined in this article. Attempts to quantify learning tasks in the modes of difference and difficulty are illustrated by the use of four diagrams: (1) a method of computing actual learning tasks, (2) two contrastive continuums, (3) a scheme of "similar-different" linguistic feature analysis, and (4) a comparison matrix. Concluding remarks bear on the necessity for both CLA and error analysis (EA) in the construction of foreign language instructional materials. (RL)