Wiki-based writing possesses a great deal of educational potential, yet students face difficulties while writing a shared document. Revising a shared document, in particular, seems to be a demanding activity for students. This study investigated whether collaboration scripts can help to improve students' revision activities and overall text quality. We compared scripted (script+) with unscripted (script-) collaboration in a wiki-based writing setting that was adapted for educational purposes. Students from two university courses participated in a one-week collaborative writing activity. Results showed that students in the scripted condition outperformed students in the unscripted condition with respect to revision behavior and text coherence. Furthermore, we found that students' revision behavior correlated positively with text coherence. Results from analyzing students' discussions during the writing activity revealed more frequent coordination with respect to task division and increased communication frequency for students in the scripted condition. Results also indicate that collaboration scripts can foster coordination. Our findings suggest that collaboration scripts are promising means of structuring collaboration during wiki-based writing. (Contains 2 figures and 4 tables.)