Evolution and Characteristics of the Transdisciplinary Perspective in the Research: a Literature Review

Evolution and Characteristics of the Transdisciplinary Perspective in the Research: a Literature Review C. Hernández-Aguilar1,∗, F. A. Domı́nguez Pacheco, Efraı́n J. Martı́nez Ortiz , Rumen Ivanov, José Luis López Bonilla, Alfredo Cruz Orea, Jose Ordonez Miranda Programa en Ingenieŕıa de Sistemas-SBAAM, SEPI-ESIME, Instituto Politécnico Nacional-ESIME Zacatenco, Col. Lindavista. 07738, Ciudad de México, México. Unidad Académica de F́ısica, Universidad Autónoma de Zacatecas, A.P. 580, Zacatecas, México. Departamento de F́ısica, CINVESTAV–IPN, A. P. 14-740. 07360, Ciudad de México, México. Institut Pprime, CNRS, Université de Poitiers, ISAE-ENSMA, Futuroscope, 86962 Chasseneuil, France ∗e-mail: e-mail: clauhaj@yahoo.com, clhernandeza@ipn.mx


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ways of deciding politics and governance (Funtowicz and Ravetz, 1996) [46]. Then, the science would be support to decision making where the uncertainties of the systems and the risks of the decisions are considered. This implies a change in the scientific paradigm; for which today it is even more understood in the face of the challenging and complex problems of our times by having a globalized world.
In this way, despite the increasing awareness of how favorable a Transdisciplinary approach can be, as stated by Gaihre et al., 2019) [47] and demonstrated by the increase in studies reported in the scientific literature introducing this perspective in the research process [48]. It is still necessary to learn from this vision and train new researchers fulfilling the characteristic features of this perspective. And not only to researchers in training, research institutions and governments, society, civil, etc.
Thus, the objective of the present document is to share a literature review about, the evolution of term and characteristic features of transdisciplinarity; as it could be the way to investigate in the near future in Latin American countries or between countries of different regions of the world; with societies characterized by their respective contexts: social, economic, educational, health, age, physical, climatic variables, ecological, geographic location, cultural, political, etc.

Pre-Transdisciplinarity
The term transdisciplinarity, for some authors, was introduced in 1970 [ [49][50][51][52][53], although the notion of the term was found earlier according to Ramadier (2004) [50]. The various benefits that science could have towards society, was glimpsed by various scientists such as Bacon, Bernard, Einstein and Bohr among many others. Einstein already expressed concern that man would evolve towards different holistic levels and feel compassion for others and the other (beings and nature). Bacon defended the collaboration between scientists for the progress of science and its orientation in a good to society, according cited by Hadorn et al. (2008) [54]. Bohr, dedicated part of his life to convince to his colleagues of the need to use the findings of nuclear physics for useful and beneficial purposes to man; the latter scientist was recognized as the one who had the notion of transdisciplinarity before the term Ramadier appeared (2004) [50].
One of the main characteristics of transdisciplinarity is to investigate for and with the communities, but this vision is found before the appearance of the term. Kurt Lewin (1890Lewin ( -1947, the father of action-research (A-R), since he started this type of investigation in 1944, although some authors indicate that it began 10 years before (Lewin, 1944;1946;Miguélez et al., 2000) [55][56][57]. Regarding this research mode, close to the community, two aspects were identified: the sociological dimension, represented by Lewin and the educational dimension by Paulo Freire , where the problematic actors became participants and co-responsible in solving their own problems. Sol Tax  was another promoter of this type of action research (Rahman and Borda, 1992) [58]. In this sense, research for society and with society (Scholz, 2000a; [59][60], is practiced since before the introduction of the term. The problems to be tackled were born from the community that lives them. Likewise, the researchers had to propose dialogue strategies with the community, where changes in society and academia are required. The changes in people, their transformation, which is another characteristic of transdisciplinarity, has also been proposed for many years, before Christ and after Christ. In the 19th century, various thinkers, mystics, spirituals, alchemists proposed walking towards the self-observation, the reflection, the internalization of man, self-inquiry, self-knowledge, etc. [61][62][63][64]; in general, to lead to the knowledge of man for the evolution and their transformation. It is worth mentioning the famous aphorism of the Greek sages in the time before Christ: "Know thyself". Marco Aurelio , stoic philosopher [65]: he reflected on the matter of "Looking within oneself". Since inside is the source of good, and it will come back, if you keep digging. In addition, for expanding the mind, he stressed the importance of systematically and really investigating everything that is observable in life. Polymaths like Leonardo Da Vinci (1452-1519) -(Scientist, painter, mechanical engineer, sculptor, thinker, city planner, storyteller, musician, architect) [66] claimed to transform oneself to transform, obstinate rigor. Some spoke of transformation towards virtue, e.g. Newton (1642-1727) recognized the virtue of having patience more than other talent for the development of his discoveries. In the case of Benjamin Franklin (1706-1790), visualized cultivate virtues, proposing the C. Hernández-Aguilar, F. A. Domínguez Pacheco, Pacheco, E.J. Martínez-Ortiz, R. Ivanov, J. L. López-Bonilla, A. Cruz-Orea and J. Ordonez-Miranda Evolution and Characteristics of the Transdisciplinary Perspective in the Research: a Literature Review 162 development of thirteen virtues, among which are: silence, order, determination, temperance, tranquility, humility, etc. Goethe pointed-out that science involves capacities of observation and thought, but also human faculties that can resonate with the spiritual dimension (Max-Neef, 2016) [67]. The empathy that must exist in research is highlighted by Claude Bernard who rejects research without feeling; as well as proposing that study the phenomena of life in the context in which they develop (De Romo, 2007) [68]. In this sense, from before the origin of the term there was already talked about contextualizing the research, i.e., having a problem or a need focused on space and place and putting it in relation to its environment and at different holistic levels and different dimensions and behavior over time; visualizing the problem in its multivariable dimension. On the one hand and on the other the importance of knowing the himself and the researcher's need to develop virtues.
Many other characteristics have been reflected on and sought throughout the history of the production of knowledge, e.g. the unity of science. It is worth mentioning a world-famous phrase from Plato (427-347 b.c), in the Phaedrus dialogue (cited in Miguélez, 2011) [69]: "If I find someone capable of seeing things in their multiplicity and, at the same time, in their unity, that is the man I look for as a god". The unity that implies reconciling and yielding, which then implies humility and many times accepting one's ignorance in certain knowledge, is a process to live, to learn to integrate as an act to unite and link parts that form a whole, one of the bases of transdisciplinarity. This is clearly reflected in the Systems General Theory (SGT), in the 50's years, which since its creation promotes the integration of disciplines (Bertalanffy, 1986) [70]. With the creation of the "Society for Systems General Theory" (Bertalanffy, 1954; see Cuadrado, 1995) [71], a research program is established, which within its principles was "to promote the unity of science by improving communication between specialists". It is one of the challenges of transdisciplinarity today. Where the language that is used is relevant, such as behaving with the other, with a different culture, a different country, a different level of knowledge, different interests, etc. So, a change in attitude of the scientist (now more commonly called researcher) was established. Schrödinger (1887Schrödinger ( -1961 [72] stressed that the scientific attitude must be rebuilt; science must be redone again. In the 1960s, at the beginning, the United Nations for Development reflected on the development process, stating "development not only refers to the material needs of man but to the improvement of social living conditions and to his noblest aspirations. Development is not only economic growth; it is growth added to evolution" (ONU, 1960) [73]. A possible evolution of the man who was, is and will be necessary for his own survival.

Origin and 1 st Stage of Development
For Miller (2008) [74], the origin of transdisciplinarity goes back to the 50s, after the 2nd. World War at the same time as the SGT. Others like Groß y Stauffacher (2014) [75] indicated the beginnings of the TD debate in 1969, when the UNESCO meeting was held in Genova, Italy. The vast majority of authors point, in general, to 1970 as the year in which the term is introduced in France (Ramadier, 2004;McGregor, 2007;Jahn, 2008;Cronin, 2008;Basarab, 2010;Sholz and Steiner, 2015a) [50,51,[76][77][78][79][80] and there is talk about it in the United States (Bernstein, 2015) [52]. Coinciding precisely with the international year of education (Maheu, 1970) [81]. On the one hand, in Nice, France is recognized to Jean Piaget (1896-1980) as who introduced the term during the Conference titled "interdisciplinarity, problems of teaching and education in universities" (Jahn, 2012) [82].
André Lichnerowicz (1915Lichnerowicz ( -1998 and Jantsch (1929Jantsch ( -1980, French mathematician and Austrian astrophysicist, respectively; related the term with the logic and set theory and education and planning issues. Jantsch defines it as the synthesis of disciplines, overcoming the multidisciplinarity and interdisciplinarity (Miller, 2008;Nicolescu, 2010) [74,78]. Jantsch (1970) [83] visualized social need as the creative force to direct, shape and organize education and research. He suggested a transdisciplinary university including systems design laboratories powered by disciplines, and departments oriented to build capacity for selfrenewal of societies (Jantsch, 1970;1972; Sholz and Steiner, 2015b; Osborne, 2015) [83][84][85][86]. In this way initially, some associate the term of transdisciplinarity with the application of SGT in the educational policy (Osborne, 2015) [86].
On the other hand, in the same year of 1970, as reported by Bernstein (2015) [52], in the United States, Jack Lee Mahan (1970) discuss about TD, incorporating ethical and humanistic considerations in this transdisciplinary approach to research. Highlighting the "reverence for life, man and the human condition". He proposes transdisciplinary research would be characterized among other aspects by a) the transcendence of disciplinary limits, b) attention to the context of the research, c) respect to the life and dignity of the human being, and d) applying knowledge to the improvement of society. In this sense, the origin of the term transdisciplinarity is found in Europe and America. It is worth mentioning that at the same time of the 70s, when the processes of environmental deterioration and degradation of the Earth become evident, Gaylord Nelson, (1970) [87], calls for awareness to protect the Earth and the life that the habitat, a message that transcended the ONU worldwide, an organization that, in 1971, decrees World Earth Day and begins a series of actions in this same consciousness.
At the end of the 70s, Kockelmans (1979a;1979b) [88,89], distinguished the transdisciplinary approach as the unit of science. The author proposes to be continually "provoked" through reflection, where it is required to do the task for everyone, not only for disciplinary philosophers, in a critical attitude. A critical attitude that implies participation, this is various actions on everyone's part. It is necessary to integrate in the research process scientists representing various disciplines, as well as other representatives outside the scientific field, the users or actors of the problem. Transdisciplinarity could then be a scientific and non-scientific work, with the intention of overcoming the negative effects of specialization. In education and research, it would be a matter of both being relevant to society.
Mittelstrass (2011) [90], self-recognizes who introduced the concept into philosophy in 1987; same year in which the CIRET (International Center for Transdisciplinary Studies) opens in Paris, France. Already previously in 1973 another Center for trans-disciplinary studies had been opened, the first of its kind, directed among others by Edgar Morín (Ramadier, 2004) [50].

Transdisciplinarity in the Decade of the 90s
Despite the date on which the term TD is introduced, and it reflects on the need for another way to investigate to participate in the world's problems. It is in the 90s; after the environmental crisis started in the 70s and later aggravated in the 80s added to other world crises. Almost 25 years after those initial ideas of TD (Scholz and Steiner, 2015b) [85], when the approach to research is resumed and it could be considered it begins to take impulse; it could be said that a first evolution of the term begins to take place to produce knowledge and mainly it is moved towards its application.
In 1991, the Swiss Environmental Priority Program began, and projects were asked to go under transdisciplinary research (Scholz, 2020) [60]. In 1992, Mittelstraß [91], asked the scientific community to reconnect research with real-world problems, transcending disciplinary limits (Hoffmann et al., 2017) [92]. It is even necessary to reconnect different disciplines, different knowledge (scientific and empirical), etc. Even within the same discipline, within the same institute, "stop rowing" each one on their own. Focus everyone in the same direction to get ahead, in the face of problems that sometimes they are even survival. Paraphrasing Brewer (1999)  , "The world has problems, but universities have departments" (Cronin, 2008;Pohl, 2011) [77,94]. Department sometimes without orientation, each walking in unknown directions, even the researchers that make up each department. For this reason, is primordial the oriented research. Where the institutes have the country's problems, in common agreement with the governments; so each one is assigned complementary tasks according to their specialties, but integrating and complementing each other, to this way redirect the course of the investigation. This process is based on current and future anticipated needs in the real world. According to the literature review and the context of the time, it was apparently the great impetus given to this vision with the contribution published in 1994 by Gibbons et al. [5], whose contribution allowed them to rethink how to do science. It should be noted that it is the document from the introduction of the term of transdisciplinarity to date (within which they provide definitions and characteristics), with the highest number of citations (according to Google academic, more than 10,000). Along with the contributions of Gibbons et al. (1994;1997) [5,7] an important event is also highlighted, the World Congress of transdisciplinarity celebrated in a region of Portugal: Arrábida. According to McGregor (2015a) [95], in this event there were diverse assistants such as the president of the country, civil society, representatives of industry, government and academics; among which were Freitas, René Berger, Ubiratan D'ambrosio, Roberto Juarroz, Edgar Morín and Nicolescu Basarab, etc. who collaborated in the writing of the transdisciplinarity charter that was one of the results of this meeting (Anes et al., 1994) [96]. Basarab Nicolescu defines transdisciplinarity as a generalized transgression that opens a space for freedom, knowledge and love (Basarab, 1996) [97]. On the other hand, Julie Klein (1996) [98] defines transdisciplinarity as the perfect interdiscipline. In this decade begins to be mentioned, the need for a language and attitude of transdisciplinary [99]. The latter term being introduced by Roberto Juarroz, recognized by Basarab (Ramadier, 2004) [50].
The TD language allows a researcher to communicate with another of his own discipline, with another of a different discipline and with the problem actor, where a reflective thought of the investigator-subject is relevant. Subsequently, Gibbons (1997; [6,7] in the second quinquennium of the 90s, continues to publish about Mode 2 to produce knowledge, where his article of 1999 stands out, at the journal "Nature", where it is incorporated the term "socially robust knowledge". He also proposes the need for science to establish a contract with society. Meanwhile, Basarab (1997) [100], proposes self-transformation, based on self-knowledge, for a new way of living. In this same year, was celebrated the International Congress in Locarno, Switzerland entitled: "The transdisciplinary evolution in the University", same that was organized by CIRET and UNESCO deriving from that event, Locarno's statement. An aspects established was the emergence of a new tolerance to achieve the exchange of knowledge. A new tolerance that allows the acceptance of differences, the acceptance of ignorance, the acceptance of the new and unknown, etc. The investigator would have to learn to deal tactfully to other disciplinary and non-disciplinary. Paraphrasing Newton: (1643-1727). "the tact is the ability to get to a point without making an enemy" The following decade, from the year 2000, is marked by another trascendental event: The Transdisciplinarity Conference held in Zurich, where that conference could be considered another relevant event related to the evolution of the TD perspective.

Transdisciplinarity from 2000
Transdisciplinarity, at a conference held in Zurich was defined as: a manner of learning and solving problems with the cooperation of society and academy to face the challenges of the societies. According to Klein et al. (2001a) [49], some participants who stand out in this event are Michael Gibbons, Helga Nowotny, Rudolf Hiiberli, Charles Kleiber, Rita Colwell, Thomas von Waldkirch, Roland Sholz, David Marks, Perrig-Chiello, Richard Ernst, Thomas Jahn, Christian Pohl and Julie Klein; the latter being the one who led the edition of the Event Report, entitled: "Transdisciplinarity: Joint solution of problems between science, technology and society. An effective way to manage complexity".
It should be noted that there were more than 220 contributions from various participants from different parts of the world such as India, Denmark, Nigeria, Holland, Spain, Indonesia, Germany, Russia, Italy, Austria, United States, Portugal, United Kingdom, Sweden, Belgium, Brazil, Ukraine, France, Bulgaria, Greece, Croatia, Ethiopia, Japan, China, Colombia, Slovenia, Israel and Switzerland, among others. In this way, the transdisciplinarity perspective in research is increased. At the initiative of the Swiss academies of arts and sciences, the "Network for transdisciplinary research (td-net)" was opened at congress of Zurich (Td-net, 2020) [101].
In Basarab (2010) [78] defends within the etymological meaning of transdisciplinarity the "beyond the disciplines", where the social field introduces that dimension, but the individual human being and his spiritual dimension should not be left aside. As well as, the scientific spirit, which is the center of TD; the transdisciplinary methodology and the scientific method complement each other.
In the interview with Basarab (2011)  In this sense, the transdisciplinarity, has undergone an increasingly integrative practical evolution (Espina et al., 2004) [111], increasingly systemic thought, which do see to the world of a different way (Max-Neef, 2005) [112]. Among other requirements for a TD-RP is the collaboration between disciplines and participatory research (Pohl and Hadorn, 2007) [113]. For this there are among others, some requirements such as a transdisciplinary training of new researchers and therefore transdisciplinary trainers of future researchers are necessary. In the declaration of the 2nd World Congress of Transdisciplinarity held in Vitória, Brazil (2005); it is pointed out that the action TD, articulates the relationship with the world (eco-formation), the relationship with the other (hetero and co-formation), the relationship with oneself (self-formation) and relationships with the being (onto-formation) (Espinosa, 2005) [114]: being one of the urgent actions proposed by Nicolescu: Transdisciplinary education, i.e. influence the training of transdisciplinary researchers; representing this one of the great current and future challenges.
Complying with the characteristic features requires knowing-self-investigating and self-transforming. In this sense, Jahn et al. (2012) [82] points out others characteristic features in the research TD, this is: a) critical, b) self-reflective, and c) relates society and scientific problems. Transdisciplinary approaches for Méndez (2013) [115], could include academic scientific disciplines, as well as different knowledge systems (e.g. empirical experience, local knowledge, indigenous knowledge, etc.) aimed at solving problems. Groß and Stauffacher (2014) [75] reported that the type of knowledge generated not only discovers laws, but also is to provide solutions to socially relevant problems. For this, heterogeneous groups are formed to produce scientific knowledge.
Then it leads to solving problems present in the real world. For which, as Miller (2008) [74] mentions, transdisciplinary research requires a social responsibility. Social responsibility implies an important individual and introspective work because it implies being responsible for the other. Paraphrasing Emmanuel Lévinas (1905-1995) "When I see you, I feel intrinsically responsible for you", implying seeing beyond ourselves (Jiménez, 2017;Martos, 2011) [116,117]. Therefore, as McGregor (2004) [118] indicates, whoever wants to adopt a TD approach should consider profound internal changes which could lead to, according to Max-Neef (2005) [67], to a different way of seeing the world that could represent a challenge as pointed out by Pohl (2010) [105]. Pohl (2010) [105] distinguishes mainly three challenges: 1) Structuring the problem together, 2) integration of participants group and 3) intervention in society. Structuring the problem together is one of the challenges, using methods that allow having the different views of the problem of the different participants of the research project, who will act, interrelationships between the participants, dialogue methods, the joint formulation of hypotheses, etc. They are aspects considered and carrying it out represents a challenge in the practice of transdisciplinarity. Another challenge that he analyzes is the integration, how to reconcile points of view between scientists and non-scientists, that is a real challenge, to establish the problem together, to define the hypothesis, from different value systems and ideas and beliefs, to reach integrate and reconcile academic research and experience. The third challenge of Transdisciplinarity is to successfully carry out the results, which implies reaching intervention in society. Projects could then take years to reach implementation. The stages of the project are to communicate results to civil society, the private and public sectors, but now it is to implement the solution proposal. Then you enter a cybernetic, recursive process, planning research, establishing it, developing solutions, implementing, verifying the impact on society, learning, analyzing, reformulating problems, new research questions, etc. and so on, a process that can take years, even decades.
It is for this reason that to overcome the challenges in the practice of transdisciplinary research, a different intelligence is proposed by the participants and constant introspective work, for strengthen the spiritual dimension.
Ubitaran D'Ambrosio who participated in the elaboration of the transdisciplinarity charter (1996) [119] notes that to face the complexity of the world and its self-destruction of the species, an intelligence is required that visualizes the planetary dimension, among others. Additionally, it mentions that an ethic is required where to change is necessary: from competition to cooperation, from separation to human interconnection, from dependence to human interdependence, from fear to love and from individualism to altruism (D'Ambrosio, 2014) [120]. In this way, there is a need for deep transformations in the investigater subject that longs to be a TD researcher, requiring in it, a training that allows to become aware of that need for self-investigation for its self-transformation, where critical Self-knowledge is essential. From where knowledge could be co-constructed as co-creators of transdisciplinary knowledge (Iván Illich, 1976; see, Vargas, 2015) [121]. The leaders of transdisciplinary research have to develop certain capabilities noted Hoffmann et al. (2017) [92]. Among which stand out: a) integrative vision, b) skills for intellectual between-disciplinary exchange between disciplinary, c) project planning, evaluate, monitoring, etc., d) reconcile multiple interests and possible conflicts, etc. In such a way, the role of the scientist takes wide relevance and transcendence. Wiek (2007) [122] reflects that the role of the scientist as an epistemological mediator between science and practice must be reconfigured. As well as reconsidering the role of the scientist as a figure to create a culture of peace, which for D'Ambrosio (2011) [123] covers four dimensions: military, environmental, social and individual peace, this being the most universal problem facing humanity (De Holanda and Medeiros, 2014) [124].
Pohl (2010) [64] pointed out several characteristics of TD, among which he highlights: 1) develop knowledge and carry out practices for the common good, 2) adopt a comprehensive, multi-perspective approach, 3) tackle problems and solutions transgressing scientific disciplines, etc. Then, the spirit of transdisciplinarity is to develop research to serve society, i.e. with mainly social sense. The perspective of transdisciplinary research would be focused on the common good (Enengel, 2012) [125].
In this way, the borders of the researchers, of the disciplines and of the specific problems themselves are transcended, seeing a complex and interconnected whole, where the unity of sciences and consciences is invited. Stokols et al. (2003) [126] suggests caution in the use of terms: transdisciplinary collaboration and transdisciplinarity to do science (TD science), because they are not synonyms. Doing science under the transdisciplinary approach is not to form coalitions involving collaborations, whose mission is for example to promote improvements in health, educational or economic conditions. Transdisciplinary collaborations aim to generate intellectual results that are their hallmark; carry out scientific research activities and generate knowledge.
Transdisciplinarity according to Klein (2001b) [127] does not begin in a specific discipline. If not, it is based on a practical problem (Hult, 2010) [128], which seeks the generation of practice-oriented solutions and their dissemination among the target population (Bergmann et al., 2005) [129]. Others authors Jahn (2003) [130] retake what was pointed out by Krott (2002) [131], indicating that the specific added value of a research project TD does not stop with the explanation of the world, but even intervenes directly in the problem or situation. In order to persist, in the intervention of the problem situation, collaboration with different disciplines, collaboration with the different actors in the problem, etc., a constant openness to change is required. Then, it will be essential for researchers and participants to continually transition mutual and transformational learning, as recommended by Mitchell et al. (2015) [132]. One of the challenges that the Transdisciplinary group faces, among many others, is to stay in unity. Starting from the differences that may exist between everyone, maintain unity and learn to agree with the other, hence the importance of continuous self-transformation. To learn to listen and not impose, etc. The members of the research project (TD) from the beginning to enter of manner individual, must be aware that it must self-transgressed, causing continuous change through self-evaluation. On the other hand, research assessment permanently is also proposed by some authors for quality assurance in the RP-TD (Balsiger and Kötter, 2005) [133].
In summary, it is possible to observe in Table 1 (see Appendix), a list that integrates some definitions and characteristic features of transdisciplinarity. A perspective to address the research in these poly-critical times, where the challenges will be to make it operable according to the contexts of the various countries and consciences of scientists and extra-scientists involved.
The trainers of future generations have various challenges in the process of researchers training, which must be transformed in order to re-educate towards a transdisciplinary perspective. The trainer must live and teach to live alongside the research process, self-research, self-knowledge due to that is useful for self-transformation. Being this basic aspect in compliance with the characteristic features of a TD research process, as shown in Figure 1, column 2.
According to the reviewed literature, Figure 2 shows by decades the behavior of the number of authors, citations of contributions and number of papers in the last fifty years. It is possible to observe in Figure 2a, how the number of authors by paper in average has been increasing over time. Starting in the 70s and 80s with a single author and the average number of authors in the last decades has increased to almost three authors. It is worth mentioning that there were articles from this literature review with 20 and 14 authors such as Axelsson et al. (2013) [121] and Benesh et al. (2015) [125], being a trend of increasing number of authors in scientific contributions from a transdisciplinary perspective.
Regarding the number of citations of contributions per decade (Fig 2b), it was found that the decade of the 1990s had the greatest impact. This is also evidenced by the number of papers, which have been increasing from decade to decade, increasing by more than 100% with respect to the beginnings of transdisciplinarity (Figure 2c). Among the papers reviewed, the most cited by decade are observed in Table  2 (see in Appendix). It is possible to observe that since the appearance of the term transdisciplinarity until today, the ones that have been most cited are the contributions of Gibbons et al. (1994), Klein (1996), Gibbons (1999), Max-Neef (2005) and Hadorn et al. (2008) [5,57,6,72,54]. Figure 3a shows the number of authors from each country who have contributed to this perspective according to the literature review carried out. Finding that the countries with the highest number of authors who have researched and promoted this perspective are mainly Switzerland, USA, Germany, Austria, Sweden, France and UK.
The transdisciplinary perspective in these critical times of COVID-19, can be a support to approach the investigation, in diverse aspects, from the integration of diverse investigators coming from different disciplines, from the sustainable results that can be offered, from the participants and their spiritual dimension that they would have to work on and in this way decide in a transdisciplinary systemic way and especially today in training researchers (Figure 4).
In such, a way that addressing the problems that are experienced require the proposal of solutions from different scientists in collaboration with those who experience the problems; as the findings occur, sensitizing and re-educating the population is necessary. Hence, the importance of another perspective to investigate, where contemplating re-education and awareness of society would be relevant. It might be up to the scientific community, in part, to teach and work with society. This would be of great impact and would allow the transformation and evolution of societies and not involution.
Our students, and future Transdisciplinary researchers: The advantage they would have is that they could have developed the necessary resilience in these difficult times, which will help them not to fall into mental problems, to avoid problems of anguish, depression, loneliness, etc. These are difficult times, the transition to a new era, but you must maintain hope to be part of the reconstruction of a better world    and to reconstruct new ways of doing science and of being human in science and in the world. Adapting to the changes of the new life will be necessary, awakening consciousness and joining the actions aimed at reconstruction or resurrection. This will fulfill what Basarab (1996) [97] said: that Transdisciplinary researchers appear more and more as hope-makers.
As is known, evaluating a project is a strategy for continuous improvement. In this way, there are proposals to evaluate both the effectiveness of the collaborating team and the aspects to be covered in a transdisciplinary project [111,184]. In the case of the evaluation of transdisciplinary projects, Klein (2004) [111] proposes a questionnaire of 47 questions divided into five categories: A) initial phase, B) organizational and conceptual framework, C) learning and social communication, D) collaboration and integration and E) evaluation, innovation and dissemination related to various aspects that can be observed in Figure 5.
Other basic guiding supports for the researcher are various methodologies that have been reported in the literature. Which are based on general phases to develop the research process (see, Table 3 in Appendix). Basically, they coincide in: 1) the need to collaboratively define and understand the problem (including its various actors), 2) the design and planning of the research process, with the participation of the actors in all phases and 3) Preparation of the research synthesis, conclusions, recommendations and communication of results in the scientific field and to the public.
Only one of the methodologies (Hernández, 2018) [177], addresses a phase to develop the self-investigation of the subjects who investigate that is necessary to carry out the research process and can serve to maintain integration and close collaboration. In addition to develop, among other dimensions, the spiritual one that is decisive in a research process of this type and finally achieve self-transformation as one progresses along the path of research, becoming more aware of oneself, the others and the other.
Finally we can say that knowing the history of transdisciplinarity, its evolution, its characteristic features, etc. could allow current and future generations to work to fulfill them and in this way co-participate in the survival of man and his world.

Conclusions
The transdisciplinary approach could represent the best pathway to develop research in Latin America countries to face the diverse problems of society. The main countries that have developed this approach and have marked some characteristic features are Switzerland, Germany, the United Kingdom, the United States, Canada, France, and some of Latin America such as Bolivia, Colombia, Brazil, Chile and Mexico; where they are performing Research under this perspective and move on in the fulfillment of characteristic features of it.
The approach is in evolution and as time passes, various characteristic features are added according to the experiences that researchers face in the practice of transdisciplinarity. It is a challenge for researchers today, above all to make individual changes that must be made that demand their self-investigation and self-transformation that allows their evolution as the research carried out evolves, also evolve each one of them.
There is increasing acceptance in the world scientific community, increasing the number of articles by more than 100% compared to the last century, but there must be a change in the policies of those responsible for making them, so that transdisciplinary research achieves its objective of intervene in systems and thus evolve societies and nations.
Transdisciplinarity presents an evolution that allows complementing its concept and its characteristic features over time.
Author Contributions: All authors contributed to this paper equally.   Morin (1988) In TD, "the knowledge operator must at the same time become an object of knowledge" (see, Carrizo and Gallicio, 2006) [134].

Paris, France
Transdisciplinarity in the decade of the 90s. Mittelstraß (1992) TD is a way of investigating that transcends disciplines to propose solutions to problems in the world of life, as quoted by Pohl (2008) [135].
Konstanz University, Germany Arber (1993) TD transfer concepts or methods from one discipline to another (see Scholz et al., 2000b) [136] University of Basel, Switzerland Kim (1998) [137] TD is the "intellectual space" where problems are thought about, their alternative solutions and interrelationships are observed. "Co-operative work"= "sinergon"  [145] Connections are made between disciplinary boundaries, between academic and experimental research. Border work is required Researchers who operate regularly in a TD manner would encourage the development of the integrative and collaborative required in research. Features: 1) The TD integrates various methodologies, it is not one, 2) collaboration with actors of the problem (affected people).
Wollongong University, and University of Sydney, Australia Galvani (2006) [153] Transdiscipline must be understood as an attitude of intellectual rigor, which allows the researcher to be aware of their own limits and the limits of their discipline. "Being transdisciplinary" for this author means being aware that everything cannot be explained through the lens of our profession or particular area, but we must accept that we need other professions and fields of knowledge, to gather all or the greatest possible number of perspectives that allow us to form a more complete idea of reality. Demanding openness not only to other disciplines, but also to classical and popular knowledge, and to the cross-cultural, including art, philosophy, spirituality, science, etc. Congress in Barcelona (2007) Pineau points out contributions in ecological training, contemplating respect for nature (ecology) and others (otherness) [154].
Barcelona, Spain Pineau of the Rabelais Tours University, France. Hadorn et al. (2008; [54,155] Research that addresses issues in the world of life. Phases: 1) problem identification and structuring phase, 2) problem investigation and 3) outcome phases. Transdisciplinary have three types of knowledge: systems, objective, of transformation, and reflects the mutual dependence.
ETH Zurich, Switzerland Peón and Hernández (2009) [156] The transdisciplinary research process is service oriented, useful to share with others or others. It always implies universal values and ethics. In addition to observing the object studied, it requires self-observation. We work for tolerance between different ideas of disciplined experts and even beyond, we work to understand the undisciplined, the empirical, the common citizen, etc. Constant awareness of unity. Focused not only on doing but also on being (Hernández-Aguilar).

National Polytechnic Institute Mexico
Casella et al. (2010) [157] TD is a way of conceiving, thinking and analyzing the reality that surrounds. Seeks to relate knowledge with life. Born for to meet the need to deal with the unprecedented challenges of the problematic world in which we live and require a multi-referential treatment because they are complex. Transdisciplinary research is based on: 1). integration of multiple disciplines and 2) of stakeholders-included levels of governance (representatives of different social sectors participate and have active inclusion in formulating problems, knowledge production and learning).