The main objective of this paper is to present the results of two studies developed to test the effectiveness of teaching different strategies for identifying important information in the context of ordinary instruction. Training in both studies can be characterised as metacognitively oriented and contextualised in content areas. Also, the same strategies have been the object of training in both cases, Previous knowledge activation and diagrammatic representation of relations among text ideas were among the main strategies trained. 31 subjects (11 to 12 years-old) participated in the first study, and 104 (11 to 14 years-old) in the second one, In both cases, subjects were divided into ttl-O groups, experimental and control. Assessment was made through an interview carried out separately with two texts, Results reached statistical significance mainly in study 2, but only for students in higher grades. These results show the effectiveness of the kind of training developed and the importance oftaking into account the developmental and/or academic level of students in order to determinate when to introduce strategy training.The mai n objective of this paper is to present the results of two studies developed to test the effectiveness of teaching different strategies for identifying important information in the context of ordinary instruction.Two lines of inquiry have served as the theoretical framework for these studies: research on instruction related to important information identification and literature about expertsnovices differences.Concerning the former, research on instruction related to important information identification -mainly based on the model of van Dijk and Kintsch (1983) -has underlined that the process of determining main ideas when reading a text is influenced by some important variables, such as previous knowledge, knowledge of text structure and application of macrorules (generalization, suppression and construction-integration). Since, in this process, some kind of failures may occur, research on instruction has been centered on the training of some of these variables in order to correct the faults.