This companion paper presents the GTETI assessment methodology by indicator, and includes a description of adjustments made since the previous edition of the GTETI (v1.1). Minor changes affect the internal structure of three indicators, and broader changes affect research process organisation. Documents assessed by the index now cover a 10-year period, including TE reports published up to December 31, 2024. All changes introduced in version 2.0 of the GTETI, published on December 4, 2025, are discussed in detail in Appendix 3.