Among all modern communication devices, mobile phones are the most powerful communication medium even richer than email or chat as it can act as a learning device despite its technical limitations. With such a learning device the learner controls the learning process and progress in his/her own space based on his/her cognitive state.
Learning through the computer or e-learning enables the learners to learn in a non-classroom environment when they are at home in front of their personal computers online or offline. However, learning through the mobile phone or m-learning provides the learners with the opportunity to learn when they are in the bus, outside or at work doing their part-time jobs. In fact, they can learn every time and everywhere they are.
Two main characteristics of mobile devices are portability and connectivity. As for connectivity, designing the mobile system must have capability of being connected and communicated with the learning website using the wireless network of the device to access learning material ubiquitously including short message service (SMS) and mobile e-mail. Portability enables learners to move mobile devices and bring learning materials .
Klopfer and his colleagues state the following properties of mobile devices: 1) portability: such devices can be taken to different places due to small size and weight; 2) social interactivity: exchanging data and collaboration with other learners is possible through mobile devices; 3) context sensitivity: the data on the mobile devices can be gathered and responded uniquely to the current location and time; 4) connectivity: mobile devices can be connected to other devices, data collection devices, or a common network by creating a shared network; 5) individuality: activities platform can be customized for individual learner .
The widespread influence of the market increased the popularity of the mobile phone, and this fulfills the need of teachers to provide tools and software for the learners in teaching contexts. Moreover, comparing with other wireless devices such as laptop computers, mobile phones are rather inexpensive having functions as Internet browsers available in most devices. With such inexpensive devices accessible to even the poorest areas and having the functionalities of e-mail or SMS, it is now possible to transfer information to and from mobile phones between instructors and learners without any difficulty.
Although learning service through mobile devices has some advantages, it has its own constraints as small screen, reading difficulty on such a screen, data storage and multimedia limitations, and the like. Many of the mobile phones are not designed for educational purposes. That is, it is difficult for the learners to use them for the task given by the teachers to be carried out. This is partly due to the initial design of such devices, and partly due to non-existence of such developed mobile phones. However, those devices which are appropriate for specific learning tasks are too expensive for most of the learners to buy. Thus, teachers should be aware of what kinds of tools learners have, and then set to chose or adapt resources compatible to such tools .
In an experiment, Stockwell demonstrated that the learners found the activities take too long to complete on the mobile devices, and consequently, some of them preferred to use their PCs to do their assigned tasks. In that experiment many learners indicated from the outset that they did not intend to use the mobile phones for doing their tasks because of the cost of Internet access, the screen size, and the keypad .