Introduction

The College of Postgraduates in Agricultural Sciences (CP) is a research, teaching and linking institution that contributes to the improvement of agri-food in Mexico, has seven campi in states such as Campeche, State of México, Puebla, San Luis Potosí, Tabasco and Veracruz covering both tropical regions such as those that are arid (^{COLPOS, 2013}). Since 1967, the CP has been a pioneer in the management of computers supporting the Mexican Secretariat of Agriculture for mathematical, statistical and administrative analysis; (TIC) in all of its postgraduate programs, continuing teacher training and training of agricultural producers (^{Santizo, 2001}). The TIC used are computers, internet, video conferencing equipment, digital whiteboards, educational platforms MOODLE and Blackboard, among others (^{García-Cué et al., 2009}). At present the CP has the capacity of infrastructure and availability to the continuous improvement in the educational processes.

In the postgraduate course of applied computation of the CP campus Montecillo, the State of Mexico constantly seeks strategies that support the teaching-learning processes through the development of software that suits the needs of training in agricultural sciences. One of these strategies was done through an inter-institutional education project CP-UNAM to provide TIC-supported courses and software developed through different programming languages such as HTML, Java, Java Script, Visual Basic, etc., for regular introduction courses to statistics and introduction to experimental designs (^{García and Santizo, 2009}).

These programs are published at http://www.colposfesz.galeon.com. The contents are still used today. Also, other proposals have been made, chronologically, those of an education model via the Internet (^{García et al. 1998}), web management of a didactic resource memory considering its semantic nature (^{Hernández-Ramón et al., 2012}), teaching material prepared with U-books and virtual reality (López-Cuevas, 2013) and a system designed for teaching information systems in universities and schools (Cisneros, 2014), among others.

For the identification of the existing needs in the College of Postgraduates in the field of computational systems, an analysis was made to know if in the CP, tools or software are required that contributes to the structuring and construction of educational materials. In September 2014, a work was proposed bringing together a group of managers, teachers, students and administrative workers to listen to them and seek solutions together regarding this problem and the use of TIC. As a result different force diagrams were obtained, one from Ishikawa, as well as different analyzes through Pareto histograms, the methodology proposed by ^{Gento (1998)} was followed. The results highlight that TIC are not being properly included in postgraduate courses, lack of training courses on technology, pedagogy and didactics, as well as poor motivation of teachers to use the technologies.

To solve this, we searched for options that were innovative and selected learning objects (OA). One of the important reasons is because it has not been experimented with and there are no publications on the subject in the CP. Later, further research on this topic was undertaken. Some definitions that have evolved over time are highlighted: ^{Wayne (2002)} considers OA as an educational material in small units, capable of connecting with each other, to develop easily interoperable learning pieces. ^{Wiley (2002)} explains that OAs are any digital resource that can be reused to support learning.

^{IEEE (2002)} describes them as a digital or non-digital entity that can be used, reused or referenced during technology-based learning. ^{Varas (2003)} states that OA are self-contained and reusable individual pieces that serve instructional purposes, must be housed and organized in metadata, so that the user can identify, locate and use them for educational purposes in web-based environments, with components such as: instructional goal, content, learning strategy activity, evaluation.

^{Miller (2004)} explains that OAs are units, generally small in scope, that aim to develop one or several components of a competition and that can present a variety of formats and include a variety of resources (text, figure, video, news, practical exercise, simulation, serious game, case, poem, musical theme, unit object, SMS, forums, etc). ^{Chiapee (2009)} considers OA as a digital, self-contained and reusable entity with a clear educational purpose, made up of at least three editable internal components: contents, learning activities and contextual elements.

As a complement, learning objects must have an (external) structure of information that facilitates their identification, storage and retrieval: metadata.

^{Aguilar et al. (2004)}, ^{Osondon and Castillo (2006)}, ^{Plan Ceibal (2009)}, Cabrera (2014) list the elements that a learning object must contain. In the Table 1 shows a comparison between these.

Table 1 Elements proposed to be part of the learning object.  

For the part of the metadata the ^{IEEE (2002)} explains that there are international standards. ^{Menéndez et al. (2010)} make a list of these standards: alliance of remote instructional authoring and distribution networks for Europe (ARIATNE); dublin core meta data initiative (DCMI); Institute for electrical and electronic engineers learning technology standards committee (IEEE) and the learning object metadata (LOM) and sharable content object reference model (SCORM).

Of the IEEE LOM V1.0 features nine elements (^{IEEE, 2002}): a) general. Information describing learning objects as a whole; b) lifecycle. Characteristics related to the history and current state of OA and all of those that were affected during its evolution; c) metadata. Metadata information itself; e) technique. OA requirements and characteristics: format, size, location and requirements. Comments for installation, other platform requirements and duration: i) educational. Educational and pedagogical characteristics of OA; ii) rights. Contains the intellectual property and conditions for the use of OA; iii) relationship. Characteristics that define the relationship between OA and other related; iv) annotation. Provides comments on the educational use of OAs and information on when and through whom comments were made.

Classification of categories. They describe OA according to a particular classification system. From the above, we can see that the definition of OA is heterogeneous, some of them are focused on TIC and some more on didactic and educational materials. For this reason, the following definition was proposed for the development of this project: “an object of learning (OA) is an interactive, self-contained, reusable digital archive with an educational purpose, made up of at least four parts: content, learning activities, evaluation and with one or more identifiers (metadata) that will be used for later search and use, able to be assembled in different teaching-learning situations and can be used within an instructional model of any educational institution for the elaboration of materials of any course”.

Later, research was sought on systems that handle OA in other mexican universities with agricultural specialties. We distinguished repositories of bibliographic objects with links to pdf documents, thesis works but not one specific for the teaching of agricultural subjects that meet all OA specifications according to international norms.

After all of the above, the following question arises: can learning objects be designed to support training courses and a repository of these that serve to train human resources in agricultural sciences at the Postgraduate College (CP)? In order to solve the question, a research work was proposed that aimed to design a prototype of a system of learning objects for agricultural sciences (SIGEOACA) and a repository to support training courses in the CP. The assumption to check was “in the CP can be proposed learning objects based on an international standard and a repository to be used for training human resources and training in agricultural sciences”.

The SIGEOACA, will allow the design of courses and with this to fulfill a suggestion of the mission of the CP, which is to endorse the commitment to educate and train creative people, share the results of research generating knowledge and improve the quality of life of the society.

The SIGEOAA will have a defined structure and tools specifically developed to work on learning objects, which, given their nature, provide units or information elements independent of a specific context, allowing reuse in various areas, for the purpose of developing, using and Share information and content with other users of the CP.

Materials and methods

The prototype of the system was based on models used to construct software applied to education and also on concepts and good practices of software engineering such as Lawrence (2010); ^{Peña (2006)}; ^{Alonso et al. (2005)}. Figure 1 shows the proposal for SIGEOACA.

Figure 1 Prototype for SIGEOACA  

Phase 1. Analysis: a literature review was made for the identification of learning objects, their pedagogical, technological and international standards used in metadata.

A study was done to know the opinions of teachers, students, managers and administrative workers on the supported courses of TIC and to distinguish the current problematic. The educational quality techniques were used (^{Gento, 1998}) with force diagrams, Ishikawa and Pareto histograms. The need was identified for the CP to have a web-based computer system to build learning objects and a repository of these as support for training courses in agricultural sciences.

Requirements: interface that allows users to elaborate learning objects based on an international standard and that is via the web. Database containing information for learning objects. Interfaces that communicate to the users with the database of the repository via web.

Phase 2 Design. The SIGEOACA offers: a computer tool for the development of OA, under international development standards (IEEE); a repository with public access to the AO created by teachers and researchers in the agricultural area; a web system that fosters collaborative work for the exchange of knowledge worldwide; the general structure SIGEOACA is shown in a conceptual map (Figure 2) and its architecture (Figure 3).

Figure 2 Conceptual map of SIGEOACA.  

Figure 3 SIGEOACA architecture.  

End user: are the users contemplated to make use of SIGEOACA: administrator, producer of objects and consultant of objects. The user interface is the visual medium through which OA consultants, OA creators, and system administrators can interact with SIGEOACA.

Server: a program that manages any application on the server side by making bidirectional and unidirectional and synchronous or asynchronous connections with the client generating a response in any language or application on the client side. Interpreter: program that translates each written instruction with a ‛human’ semantics to machine code, is responsible for reading the text instructions of the program one by one as they need to be executed and decomposed into system instructions, make the connection with the base data for dynamic web applications.

For the prototype, the database was selected on the LINUX platform, PHP and on an Apache server based on the IEEE LOM standard metadata used by most learning objects. In order to finish it was planned the interface that could take the system using the tools of PHP. Also, different quality attributes for the SIGEOACA prototype have been considered as scalable, secure (password access control system), and friendly (have user interfaces with respective menus and help). In addition, portability of learning objects is contemplated so they can be viewed via internet browsers.

Phase 3. Implementation: the steps followed for the construction of SIGEOACA; a) design of learning objects; b) installing the software on the computer to work under Linux and Windows; c) installing the Apache server under Linux and Windows; d) building databases and relationships between tables with MySQL.

Programming each of the interface parts: elaboration, editing, elimination and queries, with HTML, CSS, JavaScript, JQuery and JQueryU CakePHP Framework based on authors such as ^{Minera (2011)}; ^{López-Quijado (2012)}; Cabrera (2014); ^{Golding (2008)}, for learning objects and their access to the repository of OA and to databases (export the data to the server http://sgoacp.oacacolpos.es to have access via web).

Phase 4. Testing. In this phase the results of SIGEOACA are shown. Structure of the learning object. It was based on what Cabrera (2014) proposed and was modified enriching the objects with competences, learning styles and use of didactic materials. The metadata was based on IEEE-LOM V1.0 and only seven of these nine categories were used. The Figure 4 shows the final structure of the programmed learning object.

Figure 4 Structure of the learning object.  

Structure of the BD. The BD of learning objects. The database for SIGEOACA consists of distributed tables as follows: 29 main tables in a relational schema, 1 diagram, 1 schema, 29 indices and 29 main keys; as shown in Figure 5.

Figure 5 Structure of the relational database.  

Navigation map. The navigation map of the SIGEOACA interface is shown in Figure 6. On the map, you can distinguish the different options available in SIGEOACA. In the part of users, the system can be acceded like: administrator or producer of objects through user name and a key. You can also check the objects. For example: the user producing objects can access the registry and then the development, editing, deletion, queries, search, display and downloads of learning objects.

Figure 6 SIGEOACA navigation map.  

Interfaces. Figure 7 shows some windows of the interfaces. First the home screen, then an explanation of the system developers in who we are? Contact and registration forms, input to the user producer and creation-editing of objects.

Figure 7 Some interfaces.  

Results and discussion

Resulting objects. The Figure 8 shows two sections of the portable objects and a ZIP file with four elements that can be unzipped on a hard disk and viewed in browsers such as I Explorer, Chrome, Mozilla Firefox, etc.

Figure 8 Two sections of portable objects and ZIP compressed files.  

Phase 5. Maintenance: it will be based on the IEEE 1219 standard and consists of modifying the system after it has been delivered to users in order to correct defects, improve performance or other attributes, or adapt it to a change in the environment, this is according to the scalability of the system to follow its development will be necessary to follow up and solve to the cases that appear of correction. The corrections of processing, performance, programming and documentation due to inconsistency between the functionality of a program and the user manual.

Conclusions

The assumption in the CP can be proposed learning objects (OA), based on an international standard and in a repository to be used for the training of human resources and training in agricultural sciences is not rejected. A database has been created for the OA repository, where the instructional model formats, learning objects and material author records designed using PHP language will be stored.

The design of the learning object management system (SIGEOAA) and is being tested its operation in the course introduction to statistics and the educational platforms in the College of Postgraduates. The web system, with interfaces that allow interaction with creators and users in general. A manual has been contemplated for teachers to develop OA with this proposal. The developed web system is scalable and portable considering the needs in the CP, as well as some changes in the structure of learning objects.