In order to provide a sound basis for measurement and to continuously improve the programs, Worldfund collaborated with Mexico City-based consulting firm Aseguramiento de la Calidad en la Educación y en el Trabajo, S.C. (ACET) from the program's inception to conduct ongoing and comprehensive evaluations of the IAPE programs’ impact. Below are some key findings.

ACET’s study of the 2008 IAPE Teachers’ Collaborative cohort showed statistically significant increases in the following important indicators when compared to the pre-program baseline:

• the percentage of time that students speak English in class
• the percentage of teachers who now report collaborating with colleagues in the design of their classroom activities
• the percentage of teachers who report discussing their classroom experiences with other teachers.

The study also found that participating teachers reported greater confidence in their ability to teach English; more empathy for their students; and more appreciation for their role as teachers and for their students’ needs and that supervisors who participated in the program became more supportive of teachers under their supervision; more interested in creating appropriate teaching materials; and more interested in training their teachers to improve their practices in ways that support student learning outcomes.

A statistical analysis of free responses to a follow-up questionnaire administered by ACET to 181 English teachers who had participated in a IAPE program between July 2008 and March, 2010 identified the following most frequently reported impact indicators:

• Students demonstrate more motivation to learn and speak the language; absenteeism is down and enthusiasm for learning is up. (43%)
• Because students have more opportunities to speak English in class, there has been a significant improvement in students' pronunciation and fluency, sentence construction and listening comprehension, and students are more perceptive to uses of English around them. (31%)
• Students demonstrate increased self-confidence in the use of the language, improved self-esteem, and fewer inhibitions when speaking, all of which result in students practicing English more among themselves both in and out of class and in their daily life with friends and family members. (27.6%)
• Improved listening comprehension and oral abilities have contributed to improved writing and reading abilities, improved grammatical control, and broader vocabulary, beyond that established by official state learning criteria. (23.5%)

A 2010 comprehensive statewide study based on classroom observations and interviews of participating teachers, school principals, students, and parents from a state from which 31 preschool and elementary school educators had participated in IAPE programs identified the following key indicators of success across the state:

Impact on Teachers:

• Improved English pronunciation
• Recognition that teaching and learning can be fun
• Enthusiasm for putting new learning into practice
• A changed attitude toward and interest in their students
• Understanding of how to promote enthusiasm among students
• Ability to manage a group and capture its attention during class
• An array of new teaching techniques
• Ability to conduct classes in a more dynamic way
• Ability to conduct classes that free students to learn
• Discovery that they had an undeveloped potential as teachers
• A realization that is possible to break barriers and that it is possible to share and collaborate with other teachers
• Increased empathy for students
• The satisfaction that comes from having improved student learning in class
• Adoption of the Rassias philosophy that a good teacher must love his or her students
• A deeper commitment to service to others

Impact on Students:

• Students demonstrate more confidence in speaking English, more enjoyment of the English language and more enjoyment of class
• Students speak more, understand more, and demonstrate improved pronunciation and vocabulary
• Students seek out opportunities to practice English with family, friends, and strangers
• Students demonstrate fewer inhibitions when speaking
• Students talk about English class with their parents
• Students demonstrate more oral comprehension
• Students feel that they are learning more because their teacher speaks only English to them
• Students are more motivated to learn and they speak English with ease amongst themselves.
• Students acknowledge that they learn more from teachers who don’t speak to them in Spanish and ask that teachers not speak to them in Spanish so that they can learn more
• Parents report that students listen to English music from class outside of class
• Students read in English outside of class
• Students demonstrate a noticeable improvement in their ability to make their own decisions
• Students demonstrate increased affection for their teachers

Worldfund is currently collaborating with the Inter-American Development Bank to conduct a rigorous randomized control trial evaluation to assess multiple indicators of IAPE's impact. Preliminary results are expected in late 2013.