This study attempts to determine the relative power of six factors that might influence decisions of teachers about the content of fourth-grade mathematics: district tests, mandated textbooks, the principal's opinion, and parents' opinions. Sixty-six teachers were presented with descriptions of hypothetical school districts constructed to provide systematic variations in the presence or absence of these pressures. Teachers indicated general willingness to add topics but reluctance to delete topics. For addition of topics, district tests and objectives had significantly greater effect than other factors. (Author/JD)