Prime Archives in Education Research Teacher Informal Collaboration for Professional Improvement Beliefs, Contexts, and ExperienceDOI: 10.37247/PAER.1.2020.1Download Teacher-Informal-Collaboration-for-Professional-Improvement-Beliefs-Contexts-and-Experience Share: Newer Post Calculation of the Average Potential of a Wigner Solid Older Post Are School Factors Important for Measuring Teacher Effectiveness? A Multilevel Technique to Predict Student Gains through a Value-Added Approach