Prior research has used many variants of "be creative" or brainstorm instructions to enhance creativity in a variety of tasks. However, differences in instruction wording may lead to differences in instruction interpretation, and varying the placement of instructions before or after a written problem description may lead to differences in problem interpretation. This study investigated the effect of varying the wording and placement of creativity instructions on idea novelty, workability, and effectiveness. A randomized field experiment in two classrooms found that: (a) brainstorming and "be creative" instructions impact some dimensions of idea creativity, relative to standard instructions; (b) combining the two instructions increased the number of ideas only slightly compared with the "be creative" instruction; (c) the effect of the combined instruction varied across classrooms; and (d) the placement of instructions before or after a written problem description influenced novelty slightly. These results suggest that participant-constructed meaning of instruction may differ from the researcher-ascribed meaning and that enhancing the salience of the creativity requirement in instructions does not enhance novelty. The results also lead to propositions that creativity instructions induce a promotion focus during problem-solving and that creativity climate may moderate the impact of instructions.