Data from the Texas Assessment of Academic Skills (TAAS) were used to explore how learning environments within bilingual classes where students perform very well on the Spanish version of the TAAS are shaped by forces surrounding the TAAS and how this shaping process affects teachers. Four elementary schools were selected based on the high performance of their students on the Spanish TAAS reading tests. Instructional practices, the professional development of the teachers, and instructional materials were studied. Data suggest that the pressures surrounding the high-stakes of the TAAS set off a wave of "actions that impacted the classroom practices of the teachers. These pressures led to the scripting of curricular goals and objectives based largely on intensive reviews of the TAAS data, which in turn led to the official endorsement of TAAS-friendly instructional strategies to help meet these curricular goals and objectives. Professional development opportunities were organized in accord with TAAS objectives, and monitoring processes were established to see that TAAS-derived goals and objectives were being targeted in the classroom. (Contains 29 references.) (SLD)