Introduction

The rural extension has been discussed both from a theoretical point of view, as a practical (^{Bunting, 1986}). ^{Obreque (2010)} defines it as a non-formal adult education system, in order to help them understand the potential of scientific information, new technologies and emerging practices. Meanwhile, Aguirre (2010) mentions that the system should provide farmers with access to information, knowledge and technologies. In both views, the extensionism refers to the interaction of the productive component with scientific research, with the help of various mechanisms to encourage this productive relationship - research, external financing for its operation being necessary. Four components are then identified in a spreading process: 1) the production; 2) research; 3) the linkages between them; and 4) funding and standard whole process.

In recent years, the extensionism has evolved from an external care vision to a logic of self-management (^{Freire, 1973}; ^{Aguilar, 2004}; ^{Rendon et al., 2007}; ^{Christoplos, 2010}; ^{García-Huidobro 2010}; ^{Dominic, 2012}), and he has assisted different methods to carry out their work. However, it is recognized that the relationship between research and production is a complex issue, especially considering that this is different languages operated by actors not necessarily the same objectives in its purpose and even less in their learning methods or appropriation of knowledge. For ^{Nonaka and Takeuchi (1995)} there are two types of knowledge: 1) explicit mentioned as one possible to encode and transfer even by a third party; and 2) the tacit, that comes from experience and basically transferred by the interaction. The rural extensionism have emphasized the transfer of explicit knowledge to tacit what is known as internalization of knowledge.

Thus, extension methods are tools to convey knowledge and skills, which help introduce the results of modern agricultural practices with the objective of raising productivity in the rural sector research. Stakeholders, to watch and listen, can easily learn these skills. In addition, extension methods stimulate action, contributing to knowledge management and technology adoption, i.e. they are a key factor in the spread of these (^{Afzal, 1995}; ^{Martinez and Sagastume, 2005}; ^{Khan et al., 2009}).

Within extension methods, demonstration plots have been for many years a group or individual means of technology transfer (Figure 1). ^{Sanchez (2007)} defined as the means or instrument to obtain results to convince a community of producers. Meanwhile ^{Martínez and Sagastume (2005)} mention that the given area are used to demonstrate the effect of the application of any technology or practice of sustainable management of soil and water. ^{Castro (2002)} notes that are the geographical space where they test and evaluate technologies. In general, the goal is to demonstrate plots or convince the effect of any practical application, technology or innovation in crop management or herd (^{Sanchez, 2007}).

Figure 1. Concepts and highlights plot and demonstration module. 

The demonstration plots, also called "demonstration modules" can be considered as spaces confluence visions and ways of working, aimed at common goal of improving production processes, which ^{Brouewer et al. (2013)} referred to as multi-agents spaces. These spaces, consider the definition and implementation of a common goal, which in the case of the modules is validation, adjustment, dissemination and integration of the different elements of the extension system. This research proposes the concept of demonstration module as a space where they are tested, adjust, validate and transfer technology practices, also considering the link function between the components of the extension process. Current definitions usually granted only demonstrative and validation function, social function rejecting the link between scientific and productive and financial components of the extension process.

In Mexico the demonstration modules, are considered a policy strategy in the transfer of technology for the rural sector (^{SAGARPA, 2013}). The different actors involved in this strategy agree that the results of these modules depend on the process of identifying and selecting them.

Several authors indicate that producers are more likely to innovate when they see another producer make changes in their processes and that these changes result in improvements in the production unit. (^{Thierfelder and Mupangwa, 2015}; ^{Khan et al., 2009}). Demonstrative modules are a powerful way in the diffusion of innovations, knowledge transfer tacitly through socialization (^{Nonaka and Takeuchi, 1995}). However, simple observation has shown that it is not enough for another producer to adopt certain technology or innovation. ^{Obreque (2010)} notes that diffusion occurs when you have an innovative profile, understood as the ability to test, validate, adjust and transfer procedures and knowledge to other producers. That is, if intended to be broadcast only by visual demonstration, the likelihood that other producers to adopt, is low.

The establishment of a demonstration module as extension method involves a center for teaching and research (scientific component), an entity that provides resources for operation and monitoring (financing component) and at least one producer with the innovative profile to serve as a benchmark for other producers (productive component). Therefore, since an important part of the demonstration module is to act as liaison between the different components of the extension process, it is important to know where and with whom is established. Although the literature mentions what considerations should be taken into account in implementing them, few studies have documented the selection criteria actually using the change agents in this implementation. Thus, the aim of this study was to identify the selection criteria used by the agents of change in the implementation of demonstration modules as extension method in rural areas of Mexico.

Materials and methods

An information tool structured in two sections was designed: first, considered the identification of technical advisor; the second the criteria used by the assessor to identify demonstration modules. A questionnaire was applied to 76 technical advisors from the Sustainable Modernization of Traditional Agriculture programs (MasAgro) and Support for the Productive Chain of Producers of Corn and Bean (PROMAF). The application was due to a sampling scheme for non-probabilistic for convenience.

The identifying aspects of demonstration modules in the survey considered normative, operational and personality criteria. The first two were obtained from the review of the rules of operation of SAGARPA 2012; the third section consider study ^{CENDEC (2009)} in which own an actor with the innovative profile, required for an innovation transfer characteristics are defined; as well as an exploratory study in talks with some technical advisers. Each criterion was rated on a Likert scale of five points. They were asked to conferred a value of importance to them, where 1 is "not important" and 5 is "highly important". The Likert scale allows achieve high levels of reliability (^{Ospina et al., 2003}) also focuses on the subject to consult their opinion about an object and he will stand at some point scale (^{Padua, 2000}).

It was built a database and a reliability analysis was performed by reducing the variables to 16 from 30 originals. Then a principal component analysis (PCA) which allowed transform a set of interrelated variables used in other uncorrelated called factors or components (^{Luque, 2000}), for which the first factor is the combination that explains most of the variance and the second, who orthogonally to the first explains the second greatest variability. Finally, an orthogonal varimax rotation with ^{Kaiser (1958)} to extract the underlying components in the study variables was applied. SPSS Statistics 21 © was used for this analysis.

Results and discussion

The first component was nominated “normative compliance" for the variables that comprise and explains 17.6% of the variance (Table 1). In Mexico, agricultural extension is located in a private market services with public resource that implies compliance with the regulations issued by the Operating Rules of SAGARPA (^{McMahon et al., 2011}). In this sense, ^{Lopez (2013)} points out that the selection of producers depends on factors relating to those established by the same program. This component indicates the normative as the most important factor considered by the assessors when defining a producer as a demonstration module, giving greater importance to compliance requirements and subsequently to its function as binding entities between research, production and financing.

Table 1. Principal component analysis of the variables of identification criteria demonstration modules. 

Component two "accessibility to the plot" was called and explained 11.5% of the variance. ^{Obreque (2010)} and ^{Martínez and Sagastume (2005)} mention that the demonstration plots should be set up in places located in a central point of the rural community; ^{Gutiérrez (2010)} complements the above, noting that the plot must have good agro-ecological characteristics, and a strategic location to facilitate the participation and access of the target group to research.

The three component identified as "recognition of the producer" and explained 10.5% of the variance. This component refers to the person to be selected as a module, you must be a producer and have agriculture as their main activity, in addition to features that help to transfer knowledge, such as the power of conviction or is a referenced producer for their pairs. The latter is consistent with that mentioned by ^{Castro (2002)} in relation to prestige. The component four was called “capital producer” and explained 8% of the variance. This component highlight the features of being a capitalized and with our own machinery producer resident in the region. ^{Castro (2002)} notes that a producer module must have the resources and the disposition to make the changes and innovations that want to promote.

Finally, the component five was identified with the "diffusion potential" and explained 7.2% of the variance. This factor was influenced mainly by the variable "disposition to share information"; i.e. in this component is reflected function module to facilitate the transfer process. ^{Sánchez et al. (2013)} point out that the role of a change agent, or technical advisor, should focus on key processes and actors to promote rapid adoption of innovations. Meanwhile ^{Barahora et al. (2007)} mention that the selection of producers should emphasize influential actors and ^{Aguilar and Rendón (2010)} emphasize the need to encourage interaction key players identified by methods of social network analysis.

The fact that the identification and selection of demonstration modules depend on compliance with regulations of the operating rules implies that the selection of these modules privileging requirements review and not the potential for diffusion of innovations. According to ^{Obreque (2010)} transfer for innovation should focus on entrepreneurs or leaders; ie, people should be selected most likely to succeed. In this sense ^{Wejnert (2002)} mentions six important aspects of innovators to consider: familiarity with innovation, socioeconomic characteristics, personal characteristics, social organization, image to the other producers, and position in the social network.

From the above attributes identified by ^{Wejnert (2002)} the first three relate to individual characteristics of the producers; the remaining three also involve the environment and social ties in which they are located. Thus, the results of this research indicate that in Mexico there is a predominance in the consideration of individual attributes and little consideration of issues related to social and technical interaction of producers. However, consideration of regulatory aspects of relational not be considered just a problem of the rules governing extension programs, as these rules are very broad in defining its target virtually any producer can be the subject of attention population.

Conclusions

In Mexico, the establishment of demonstration modules is based on normative aspects and location of the plot where they are established. This was due to compliance with rules of operation of programs and projects as well as attending to the theory that the producer learns through observation. However, the regulatory aspect and location, it is not related to the function of integrating research, production and diffusion of innovation that seeks to establish a module.

It is suggested that technical advisers should focus more on producing good diffusion capacity, from the universe of producers that meet regulatory requirements.

Compliance with regulatory aspects limits the work of the technical advisor to identify producers with better potential in testing, tuning and diffusion of new technologies. It is proposed that the extension service considers strategic aspects in the selection of modules such as: identification of key players who are highly referred by their peers as a true source of information; the ability to undertake radical changes in the production system; and disposition to share information to other producers. Currently, extension services act first placing those who meet the standard, then those with power and diffusers.

This research aims to recognize the role of disseminating the demonstration modules will favor the integration of connectivity criteria producer. Future research could consider identifying criteria used by larger groups of technical advisers, in other programs and under different objectives. This will lead to greater empirical evidence to suggest methods of selection of modules, even under current rules extension programs.