This dissertation investigated the acquisition and processing of anaphora by learners of English, using both "offline" methods such as paper-and-pencil written tests and "online" methods such as self-paced reading-for-comprehension. Three experiments were conducted. The first two experiments tested advanced Chinese ESL learners' knowledge and processing of anaphora. The focus of the first experiment was on whether participants automatically use gender and number cues, and verb information to interpret pronouns and reflexives during online processing. The second experiment manipulated gender and pragmatic cues to test whether participants have acquired knowledge of structural constraints on reflexive interpretation (i.e., the binding principles). The third experiment, using a pretest-treatment-posttest design, investigated the efficacy of computer-delivered Processing Instruction (PI) on the acquisition of structural constraints and the use of those constraints during reading. During the pretest, subjects completed a self-paced reading task and a written test. For the treatment, participants learned the grammatical constraints on reflexives through interaction with a computer program. Posttest assessment included one interpretation test, one sentence completion task, and one self-paced reading task. The role of feedback in Computer Assisted Language Learning was also examined. Results showed the following: (1) Advanced L2 learners were more sensitive to certain types of agreement information (gender) than others (number). (2) PI improved L2 learners' knowledge about constraints on reflexives as measured by offline tests. (3) PI led to improvement in learners' processing strategies as measured by online tasks. (4) No significant difference was found between the implicit feedback group and the explicit feedback group in the third experiment. Overall, this research highlights the importance of multiple types of assessment that tap the acquisition of grammatical knowledge as well as the proficiency with which learners use that knowledge during reading comprehension tasks.