This document outlines the methodology used in a study about teachers' expectations of students' performance in public schools. The study was conducted at two schools, a high school and a university, in Puebla, Mexico. A qualitative research approach was used to understand the social and educational factors that influence how teachers form expectations. Semi-structured interviews were conducted with two teachers who have over five years of experience teaching English at public schools. One interview was conducted in-person while the other was done using WhatsApp. The interviews were conducted in Spanish and recorded for transcription.