The Obutchénie journal has graciously consented to the publication of this dossier, which is dedicated to the study of the oeuvre, ideology, and life of the Ukrainian psychologist and linguist, Vladimir V. Repkin. Regarded as a preeminent contributor to a coherent and consequential psychological-didactic framework within the domain of developmental learning, Repkin (1927-2022) led a prolific and extensive life.

However, his theoretical and didactic contributions remained relatively obscure in the United States until 2003, when Elina Lampert-Shepel, a Ukrainian psychologist based in New York, USA, undertook the commendable initiative of publishing an article of his in English in the Journal of Russian and East European Psychology (vol. 41, no. 5, September-October, pp. 10-33), entitled "Developmental teaching and study activity." Subsequently, the same text was published in Brazil in 2014, on the initiative of Roberto Valdés Puentes, in Ensino em Revista (v. 21, n. 1, Jan. /jun., p. 85-99), based on the translation work carried out by professors Maria Auxiliadora Soares Farias, Stela Miller, and Suely Amaral Mello, members of the research group named: Implicações Pedagógicas da Teoria Histórico-cultural/Unesp/Marília, (Pedagogical implications of cultural-historical theory)

Since the second decade of this century, this situation has undergone significant change, primarily due to the efforts of members of Gepedi (Group for Studies and Research into Developmental Didactics and Teacher Professionalization) who have dedicated themselves to the task of locating, systematizing, translating, and analyzing relevant materials. To date, 14 texts by V. V. Repkin have been translated into Portuguese and published in Brazil (^{PUENTES; CARDOSO; AMORIM, 2021}; ^{PUENTES; MELLO, 2019}; ^{PUENTES; LONGAREZI, 2019}; LONGAREZI; REPKINA; PUENTES; REPKIN, 2023; ^{PUENTES, 2023}). Five book chapters on his life, philosophy, and oeuvre have also been translated into Portuguese (PUENTES; According to Longarezi (²⁰¹⁹), Longarezi (²⁰²³), Repkina (2023), and ^{Puentes (2022}, ²⁰²³), four theoretical articles on his scientific activity (^{Puentes, 2022}, ²⁰²³; Puentes; Cardoso; Amorim, ²⁰¹⁸; Puentes; Amorim; Cardoso, ²⁰¹⁷). In addition, there is a master's thesis (^{Amorim, 2021}).

This Dossier continues this work by analyzing the contributions of V. V. Repkin's work to thinking about and debating issues of education and didactics. The present dossier is the result of a significant collaboration among researchers from Russia, Ukraine, and Brazil, some of whom had close professional ties with V. V. Repkin. The dossier comprises nine texts. The initial segment of the present dossier contains texts authored by Ukrainian psychologists, students, and collaborators of Repkin, including Alexander Konstantinovich Dusavitskii's, entitled "Theory of Developmental Learning (TAD) and V. V. Repkin: Experience of Biographical Study," and Natalya V. Repkin's "Vladimir Vladimirovich Repkin: Notes for a Life Story." Additionally, the dossier features an article by V. V. Repkin himself, titled "What is Imagination?"

The second part of the volume contains articles authored by Russian researchers, including Elena Vadimovna Vostorgova, who contributes two articles: "The textbook as a means of forming study activity: why do we need textbooks in developmental learning?" and "He was a teacher with a capital letter. He felt the breath of the school very well," as well as Vladimir Kudryavtsev's "The last of the Mohicans of developmental learning: in memory of Vladimir Vladimirovich Repkin."

The third part of the collection features an article by didactic researcher Roberto Valdés Puentes, titled "V. V. Repkin: Conception of the Subject of the Activity of Study (1990-2021)," and Flávia Pimenta de Souza Carcanholo's "V. V. Repkin's contributions to reflections on learning in the Activity of Study that considers subjectivity' and Geandra Claudia Silva Santos and Alexandra Ayach Anache's 'V. V. Repkin's contributions to thinking about the education of students with intellectual disabilities: introductory notes'.

The collection of texts published here suggests that V. V. Repkin's life was primarily devoted to his work until the final moments of his life.

The organizers of this collection aspire for these texts to reach a substantial audience, particularly future and trainee teachers, and extend their best wishes for a fruitful reading experience