Procesamiento – segmentación de núcleos de las células

One of the key issues with teacher- training practices is the extent and type of collaboration between teacher- training institutions in Mexico and Mexican schools (see also Maandag et al., 2007). These teacher- training institutions are understood as universities, colleges of higher education and any formal body that provides and accredits teacher training that is separate from the practice sites. Maandag and his colleagues (2007) developed a fivefold model to explain this relationship. The first model is a work placement model. Here most of the training activity takes place at the teacher- training institutions and members of these organizations have full control over the programme being offered. The second model they propose is a coordinator model, where most of the training activities take place at the teacher- training institution; however, the school takes on the responsibility of coordinating, and to some extent delivering, the supervision of the student teachers in the schools. The third model is a partnership model, and here training activities are shared between the teacher- training provider and the school. The school provides instruc- tion in the subjects to be taught and in the most appropriate pedagogical strategies, and the school provides placement opportunities, practice in

situ and some evaluative activity about the performance of the student.

The fourth model is a network framework, and here training activities are shared between the teacher- training institution and the school. The duties of each are very similar; however, there is a much more intensive

relationship between the two, with tutors moving between and operating at both sites. The fifth model is a training school model, in which all the training takes place in the school. In this model, the teacher- training insti- tution can be thought of as a reserve and reinforcement body, undertak- ing some training of the school and school- based tutors and developing teaching and training methods. In some scenarios, the teacher- training institution disappears altogether.

The five models allocate different roles and responsibilities between the teacher- training institution and the school, with the first and last of these models representing scenarios in which one or other of the two providers, the teacher- training institution and the school, have almost complete control over the contents, organization and accredita- tion of the programme. In the third and fourth models, there is greater pedagogical and curricular collaboration between the school and the teacher- training institution, although the extent and nature of this collaboration may vary considerably depending on the individual pro- gramme. For novice teachers, there may be less of a distinction between different elements of the programme or different sites of formation in the fourth model than in the other models, whereas for the first and last models processes of formation may be experienced as either institu- tional-or school-based.

Initial teacher training can be organized in two ways. In the con- current model, academic subjects are studied alongside educational and professional studies throughout the duration of the course. An exam- ple of this is the Mexican Bachelor of Education programme. This kind of programme has several benefits; and in particular, it allows a more integrated learning experience, since pedagogical training and subject- matter (content knowledge) training take place at the same time. These kinds of programmes can also have disadvantages; notably, they are less flexible than consecutive models, since the students are required to decide if they want to become a teacher at a very early stage in their uni- versity studies. If teacher-training is accessible only through concurrent programmes, it can create difficulties to becoming a teacher for those who have studied something other than education in the first place, as well as for those who are interested in becoming teachers, but who might also want to re- enter other labour markets eventually.

In the consecutive model, the specialized courses in peda- gogy and in teaching are accessible after having completed another degree in a discipline taught in school (teachers are educated first in a specific discipline and then they receive pedagogical training). This model is more common for senior schoolteachers than for basic-level

schoolteachers. Its main advantage lies in the fact that it allows a flex- ible entry into teacher training. Indeed, since the aspirant teachers already have another degree, they can convert themselves more easily if their interests or job perspectives change. This flexibility also makes them better equipped if there is a change in labour market conditions. In some subjects, it is essential for the teacher to have a strong sub- ject expertise that can sometimes be achieved only due to prior stud- ies in that specific field (for example, in mathematics or history). The negative aspect of such an initial teacher-training programme is that teachers formed through the consecutive model can have a weaker knowledge in learning techniques and in pedagogy in general. Since they have studied in two different cycles, where they learned two dif- ferent aspects of teaching, their learning process is fragmented rather than integrated.

In an education system, both consecutive and concurrent models can coexist. There are advantages and disadvantages to this coexistence. Having several programmes of initial teacher training attracts into the profession different types of potential teachers, and this is particularly important in a country such as Mexico that has in the past faced teacher shortages. Indeed, concurrent model programmes attract students that feel they have a teaching vocation, and consecutive model programmes allow the aspirant teacher to first study something else, before under- taking a programme of teacher training. Having several teacher-training programmes, based on different models, can represent an extra cost to the country and be less efficient.

In general terms, entry into concurrent education programmes is based on secondary school results and entry into consecutive courses depends on the results of university studies. In some countries, there is strong competition to enrol on teacher education programmes; in others teaching as a career is considered to be a fallback position, in that it was considered to be a second or even third option on graduation from the university. In Mexico, this latter position is more likely to be the reality.

The length of the period of initial teacher training varies round the world between a three- year period to, in some countries, six years. In the latter case, an important consideration is the capacity to con- duct and use research, both in situ and elsewhere. There are elements of this in all teacher- training programmes round the world. Schwille and Dembélé (2007) suggest that there are many factors that have to be taken into account by policymakers when deciding the length of initial teacher training: economic constraints, the potential shortage or abun- dance of teachers, the amount and quality of teacher candidates’ content

knowledge, their capacity for pedagogical knowledge and the state of the labour market in general.

One of the most recent and important trends in teacher education is the development of alternative pathways into the teaching profession. These programmes have been developed in situations of teacher short- age; their main purpose is to increase the supply of teachers in areas of need, geographical or relative to a particular subject (IT, languages, mathematics, etc.). It is possible to highlight several characteristics that define this model: the programme is short, and the preparation is mainly organized through practical training. Also, a low priority is given to edu- cational theory and research and to scientific knowledge. They rely on the candidates’ previous education to provide adequate grounding in the subject matter. The curriculum itself emphasizes learning by doing. Another common form of continuing training is the cascade model; a select group of teachers are trained and are then expected to transmit the ideas at the school level to other teachers. This form of continuing train- ing usually occurs when the educational authorities’ principal concern is to reach as many participants as possible in a short time, and on a short budget, for example, with indigenous populations in Mexico.