Segmentación de la cromatina

There are perhaps three dominant models of teaching and preparation for teaching: craftworker, executive technician and professional learner. We consider each of them before giving reasons for preferring the lat- ter. Models are representations of the real world, without the extraneous detail. They are not the real world and it would be a mistake to think that they are. They are designed to help us better understand how the world works. However, their use raises a number of questions: for exam- ple, what representational purpose do they have? What kinds of entity are they? And what is their pedagogic function? In addition, any model that we articulate has normative elements, that is, we are explicitly sug- gesting that this model is better than other models that could be devised. There are four ways of distinguishing between different models and judging that one is better than another. The first is epistemic: a model is superior to another because it is more empirically adequate. The sec- ond is the converse, so that a version of reality is better than another because it contains fewer contradictions, disjunctions and aporias. A third approach focuses on the giving of reasons, and concludes that some reasons and systems of rationality are superior to others, and there- fore should be preferred. A fourth approach is pragmatic in a philosoph- ical sense: a model is better than another because it is more practically adequate or referenced to/ part of extant frameworks of meaning. Any successful model of the teacher- training curriculum and its associated pedagogies in Mexico therefore has to be more coherent, more empiric- ally adequate, better referenced to frameworks of meaning and is under- pinned by a more apt rationale than other models.

Craft knowledge has the following characteristics. It is rooted in practice and in the routines that shape practice, and this rules out certain types of learning or pedagogic approaches. This means that imitation and scaffolding various attempts to perform the activities are key to the development of this type of knowledge. The teacher or facilitator is the expert practitioner and knowledge is derived from exposure to the per- formances of the expert. The expert is therefore not primarily a skilled pedagogue but a skilled practitioner. The emphasis is placed on observ- ing and imitating the practice. The justification for this is that the nature of the practice is better understood in these terms, that is, the learning object, becoming and being a good teacher, is a craft activity.

Craft knowledge values situated understanding and downplays the importance of technical know- how and critical reflection. This leaves little

room for what might be called research- based knowledge, even if this is understood in a non- technicist way and as having a non- binding quality to it. Though advocates of craft- based knowledge accept that there may be a role for systematic propositional knowledge, this is confined to what is taught, or subject- based knowledge, rather than to the processes of teaching and learning that the teacher or student teacher is engaged in. Furthermore, this entails a clear separation between content and process knowledge or between the learning object and the pedagogic process. In addition, this focus on practical judgements as the essence of the teach- ing activity fails to account for ethical and epistemological elements in the judgements teachers make. These judgements as a consequence of their lack of reflective critique and adherence to external expert judge- ment may be conservative and potentially unreliable, based as they are on observations of existing practice and common popularizations.

The second of our teaching models is the executive technician. This requires the teacher to perform in a particular way: to have, and be able to execute, a repertoire of pre- conceived actions. In this model, teaching is a rule- based activity and learning is understood as the assimilation of these rules and ways of enacting them, without recourse to critical reflec- tion or situated understanding. The executive technician model (see also Winch, 2014) recognizes the value of research findings, and this means that it is not thought appropriate for teachers to interpret those find- ings for themselves. Mexican educational researchers generate findings which can be expressed as protocols for action, and the role of the teacher is to implement these protocols in the most efficient way possible given that there are always situational constraints. One consequence of this is that the knowledge which is being transferred tends to lack a sense of change, emergence, immediacy or relevance. This positions the learning object, these rules and protocols, outside space and time and effectively reifies it. This also applies to the assimilative and performative functions of learning.

These rules are identified by researchers and practical policymak- ers as external to the setting. They are not situation specific or even sensi- tive to the particularities of the setting in which they are being applied. Educational research is understood as the making of nomothetic state- ments about educational activities; educational disputes about how teachers should behave in the classroom are settled by atheoretical and value- free empirical enquiry and theoretical knowledge of educational matters is thought of as superior to practical knowledge. As a result, practice is understood as the efficient application of theoretical knowl- edge constructed by professional experts. Learning at pre- service and

in- service levels then is reduced to the assimilation of these rules and to ways of following them in concrete situations such as classrooms. A more refined version of the executive technician model is that educational propositional knowledge should not be understood as being applicable in every possible circumstance and as having a certainty of outcome, but it can act as a guide to practical action. This brings back a measure of interpretative activity into the proceedings.

Both the craft and executive technician models can be contrasted with a professional learning model. Professional learning emanates and is derived from an understanding of the characteristics and func- tions of being a classroom teacher in the context of where that teaching takes place, in this case, Mexico. Apart from the content and methodo- logical knowledge that teachers need in order to plan and teach a les- son, they also have to take a variety of other factors into consideration and integrate them in a coherent, efficient and pedagogically effective way. Among these are the previous knowledge, schooling biographies and expectations of their students, the individual differences between them (e.g. capabilities, interests and motivations), the objectives of the programme and the overall institution, as well as their own pedagogical aims, theoretical assumptions and values. Teachers have to make a con- siderable number of instantaneous and ad hoc decisions. They need to react to and take the lead in classroom interactions and modify their plans and methodological procedures according to the needs of students at specific points during the lesson. Ideally, they should create an atmos- phere that encourages learning and communication and make sure that the task level is neither too high nor too low. In addition to this, institu- tions as well as classes have their own particular norms and patterns of interaction and communication. Teachers play a key role in mediating between this institutional culture and their students. They usually deter- mine the content of classroom talk, organize the distinct phases of the lesson, determine the behaviour that is expected from students, select who is permitted to respond to a question or contribute to a discussion, decide what kind of answers are regarded as valid and so forth.

The fact that teachers have to take a multitude of sequential and simultaneous decisions which have to take account of personal, inter- personal, interactive, disciplinary, pedagogic and institutional factors requires a new approach to in- service teacher training and development. Imposing a pre- defined and fixed innovation on teachers (and students) in diverse institutional and regional contexts in a coercive, top- down fashion is counterproductive and likely to make them revert to safe and routinized practices. It seems more promising to encourage practitioners

to try out new ideas in their classroom, to make adjustments and then justify their decisions. To this end an awareness of the contexts teachers work in and their own behavioural and communicative patterns is devel- oped. Participants analyse their own classes, strengthen their communi- cative competences and classroom management strategies, and amplify their pool of teaching resources.

Donald Schon, in his seminal work The Reflective Practi tioner (2005), focused on how practitioners operate and learn in workplace set- tings. He suggested that most of our knowledge as it relates to action, or knowledge- in- action, is implicit. It does not involve conscious processes, so that actions, recognitions and judgements are skilled activities carried out spontaneously. Equally implicit is the knowledge the practitioner holds about the background, the history and the social embeddedness of the respective practice. This might lead one to conclude that professional action is basically a problem- solving activity where reflection and existing tacit knowledge is applied to emerging problems. Schon however argued that this widespread understanding of professional practice is too limited and has to be extended to problem setting, a more complex form of reflec- tion, where the practitioner considers wider concerns and implications of the problem. These include institutional, political and social structures external to the workplace itself (in our particular case, the classroom) but which impact on it. At this stage, the practitioner sets in motion a pro- cess of renaming and reframing of the problem. Indeed, he or she might not even consider the issue at hand to be a problem anymore; though it is more likely that this meta- process will provide the learner with a differ- ent type of problem requiring a different type of solution.

Reflexivity and conscious analysis become even more necessary when the professional is confronted with new situations and as a conse- quence, has to change or acquire new practices. Though the individual perceives the new situation to be unique in the first instance, to make sense of it requires its assimilation into existing frameworks of rules and resources. People do this by looking for similarities and differences. Schon understood the process of learning as cyclical with successive iter- ations of comparing new and familiar experiences with well- established routines of thinking, many of which the learner (in our case the teacher- practitioner) may have difficulty with bringing to consciousness. In pro- fessional practice, however, the individual also interacts with and acts upon the environment. They attempt to make sense of it in an experimen- tal fashion that involves the following non- sequential processes: explor- ing the possibilities inherent in the problem; developing a series of action steps; testing them out to see if they fit the problem; and evaluating the

more successful solutions to develop working hypotheses. Experimenting in practice then is both reflective and transactional. The teacher is at the same time testing out new hypotheses and seeking to change the external setting in which the problem is embedded.

Professional development in this model is therefore a process of reflection in action, with different degrees of complexity, and reflec- tion on action, where teachers have to be encouraged to experiment with and explore new practices, contents and procedures in their actual workplace contexts and to think about their relevance, usefulness and viability. Reflection however, can be greatly increased through collabora- tive meaning making, dialogue and discussion between different practi- tioners who can add alternative perspectives, ideas and experiences. The exchanges between teachers from the same or different schools provide a further level of reflexivity to the teacher development programme, namely reflection on reflection in and on action.