Limitations on service technologies

However, as with many other recent technologies, SOA and web services are neither perfect nor robust. Technical challenges indentified in this chapter have suggested that service technologies have the following weaknesses when used to implement our framework.

As we have mentioned before in Chapter 2, educational resources are not only limited to educational software such as the plagiarism detection tools, but also including storage space for learning contents such as MERLOT, or learning environments that runs these contents such as Moodle. Current service development platforms mainly

support the development of web services from existing software applications, and there are not too many guidelines available to support the development of other educational services such as data storage space or learning delivery platforms.

Services technologies allow large amount of structured and unstructured educational data to be shared or accessed externally over the network. However, managing these data is not straightforward. Problems at step 2 and step 4 suggest that, depending on the nature of different educational software, not all of them has been designed or set up properly to support data sharing, some of them do not have their own database, and indentifying and structuring the data to be accessed externally is still not straightforward. There are also challenges in managing data that are passed around within the services community. Abadi (2009) has pointed out that data loss or unavailability could happen at runtime. Additionally, some large resources providers have data centers throughout the world, this might raise challenges such as data format inconsistency at different data centers, data storage at remote and perhaps unreliable locations, data transfer between untrusted hosts (see problem at Step 6) and so on. There is not too much discussion available to cope with these data management concerns in web services.

Currently, web services support only the request-response style of interaction between the clients and resources, with only four message exchanging patterns: Input-Output, Input-Only, Output-Input, and Output-Only. This is reasonable in the web based world. However, nowadays, the user interfaces are not only limited to the web browsers, two dimensional displays. Touchscreens, popup windows, color highlighting are increasingly attractive to common users and new start ups. The change of clients’ interaction needs has increased the difficulties ‘to design in details every mode of interaction for every application and platform imaginable’ (Cerf, 2012; Richards et al., 2012).

Finally, there are also shortages in resources management. Although some services experts have suggested potential approaches to address this (Georgakopoulos and Papazoglous, 2009), there is still not a commonly agreed data standard that has been mentioned to record and monitor the performance and usage of each educational resource. As we have discussed in Step 4 and 5 in Section 6.2, information could be considered to include how often each resource has been used, by whom, how well the resources have performed over time, and whether they are still available, up to date, accessible, trustable and so on. In terms of supporting technologies, some of current service bus products, such as the Oracle ESB (see Section 4.5.3), support the visual representation of service relationships, management and monitoring of services operations, however, they are commercial and designed for only general or business purposes.

6.5

Summary

To summarise, our proposed educational services framework is valid to support the resources description, discovery and monitoring. However, having considered web services and SOA in our educational services framework is the initial stage for improving the sharing and reuse of current educational resources. Our service development experience and literature reviews have suggested that a number of challenges still remain to implement our services framework, especially for resource development, data management and web accessibility among indentified educational resources:

 To share more complicated types of educational resources such as e-learning environments or platforms, and e-learning data storage spaces;

 To better structure and manage data are shared and accessible within the services community;

within the community, as well as considering more interaction styles between varied users and resource providers;

 To better report and monitor the performance and usage of connected resources as a group and as individuals, in order to create more research and commercial values via sharing educational resources.

We suggest that to improve the sharing of educational resources further should not only consider web services technology. According to literature surveys we have conducted throughout this research, until the end of 2009, there were few extra features or potentials which had been added to current web services technology, in particular none addressed the challenges we have discovered above. Alternatively, cloud computing and its cloud services, have become more of interest in academia and industry since then. Some experts even argue that cloud computing has potential to develop data storage services and platform based services, as well as to improve data availability and durability within the community (Abadi, 2009; Rafique et al., 2011; Sitaram et al., 2012). However, this technology has not fully matured yet (Ma and Zhang, 2012), it is hard to predict now how far cloud services can go, how many challenges and how well this technology can actually cope with, and whether or not other novel technologies will replace it and when (Rittinghouse and Ransome, 2010; Moyer, 2011). The study of cloud technology is out of scope of this PhD research.