Share's "self-teaching" model proposes that readers acquire most knowledge about the orthographic structure of words incidentally while reading independently. In the current study, the self-teaching hypothesis was tested by simulating everyday reading through the use of real words, analyzing the effects of context, and considering the independent contributions of general cognitive ability, including rapid naming ability and prior orthographic knowledge. A total of 35 first graders read short story passages in English embedded with target words representative of words likely to be known orally but not orthographically. Words were manipulated for target word spelling and contextual support. According to the self-teaching model, words correctly decoded during reading should be correlated with subsequent orthographic learning. The results of this study confirmed this prediction. Self-teaching was evidenced through significantly higher proportions of correctly identified target words across context conditions. Regression analyses showed that individual differences were related to prior orthographic knowledge and predicted students' degree and quality of orthographic learning after controlling for general decoding ability.