The many applications of wikis provide vast potential for use in myriad educational contexts, but limitations and challenges to their use do exist. As most of these are common to more than one (if not all) of the conceptual frames guiding this discussion, they shall be covered here on one inclusive page. The aspects of use affected by each limitation and the nature of the limitation itself will be discussed, and possible solutions and work-arounds suggested.

Accessibility and inclusion

A student with disabilities or social / cultural issues affecting their participation in on-campus studies may find that within the online environment, the nature of their challenges may become entirely different. Wikis and e-learning in general offer more opportunities than challenges for inclusive teaching practices, and it is possible to tailor material and course provision to adapt to a particular need.

• Written information may be supplemented by audio recordings, and many operating systems include text-to-speech capabilities for sight-impaired persons.
• For those with hearing impairments, working in a visual medium resolves issues of being unable to hear lectures on-campus, and voice-recognition software also exists. Video lectures or presentations may be captioned prior to embedding upon the wiki page, and transcription documents may be discretely attached via file sharing without filling the page with the transcribed information.
• Wikis provide a learning and collaborative environment that is created free of any cultural or social context, and wherein users may personalise their contributions and user profiles as much or as little as they like. The neutral environment allows users to participate on a level playing field, free of any extraneous factors such as appearance, background, or socioeconomic status that may adversely affect interpersonal interactions in person on-campus.
• All student interactions are visible to all members and to faculty staff, and may be moderated by both students and the lecturer. The nature and circumstances of any interpersonal issues or conflict are visible, aiding lecturers in addressing the issue and working with students if need be in mediation and resolution of the issue.

Extraneous cognitive load

Of all the web 2.0 tools wikis have potentially the greatest variety in appearance and utility due to their versatility and any integration of other tools. A wiki overloaded with various media and interactive tools can rapidly be overwhelming for any user to navigate and use, not only those naïve to online environs. Whether creating a wiki for students that will be mostly managed by faculty, or requiring wiki-based activities of students, the inclusion or otherwise of media such as images, videos, or sound files, and the style of formatting and overall presentation must be kept in check. Any dynamic website incurs added load due to the need to remain abreast of changes if they occur rapidly, and addition of distracting and unnecessary material or formatting will make the wiki unpleasant and unwieldy to use. Some tips to keep cognitive load in control:

• Avoid discontinuous formatting. Select a style of presentation to maintain throughout the website, and avoid gratuitous use of type colours and font choice. Wiki text editors upon every page provide formatting options such as various heading levels to assist in maintaining a presentation style, making it easy for readers to identify sections of text upon a page; this page uses level three headings for these discussion sections, and a level two heading at the footer for the 'next page' link. Recommendations may be provided for students to adhere to in their project wikis, similar to formatting requirements for papers.
• Keep it clean. Images are excellent to brighten up pages, illustrate a point, and to break up vast tracts of text, but unless relevant to the document more than a couple of images upon a page or within the visible region of a larger page can appear cluttered.
• Avoid embedding several types of media or interactive tools upon a page; a page for twitter feeds and another for video resources is cleaner and easier to navigate than pages that are a patchwork quilt of content. Where it is appropriate to combine media types upon a page, clear formatting and separation of areas can help avoid the jumble.
• The 'Pages & Files' index of a wiki is a list of material that is ordered only by page or document title, but there is no pagination upon the site, and unlike a blog there is no temporal order to content. Providing arbitrary page numbers and 'next page' links at the bottom of each page aids in providing directionality and guiding readers through a wiki that has any regions requiring order of reading. This wiki has pages that are both paginated by this system to 'tell the story' in order, as well as pages that are grouped according to title but which are standalone pages that may be read in any order.
• Judicious use of tags and keywords assists readers in locating all resources of a particular subject. This wiki has a tag cloud to the right of this page within the navigation panel, and upon the front page list widgets have been created which list every page within certain tags.

Issues of collaboration and teamwork

Designing collaborative tasks does not necessarily ensure that students will in fact collaborate effectively. Successful use of wikis for collaboration require equal input from all members, consistent quantity of work throughout the project timeframe, and a strong dialogue of commentary between members as work progresses. Common problems include: The presence of 'passenger' members, such as demonstrated by data from one wiki in which the most productive 10% of members contributed a disproportionate 40% of the work; a rush of work as the deadline approaches, rather than consistent contribution upon which others may have time to contribute and comment; and a lack of utilisation of the commentary function on wiki pages, contributed to at least in part by the aforementioned problems. These issues represent a failure of wikis or the task at hand to fully capture members, as well as failure on the members' part to make best use of the wiki platform. (Judd, Kennedy, & Cropper, 2010; Witney & Smallbone, 2011).

Possible remediation includes:

• Judicious determination of group size - large groups increase the likelihood of passenger members, whilst smaller groups (such as this wiki's authorship of just two) may not have the 'critical mass' to work properly, as communication may be more convenient by email.
• Strongly expressed guidelines to participants of the high standards of both quality and quantity of contribution required. This may be expressed as a ratio of contribution, a minimum word limit expectation for each member, and the requirement for the group to demonstrate a consistent level of interaction through commentary discussions.
• 'Rules of Engagement' to assist students new to collaboration and online group work to adjust. This may include the appointment by the group of specific tasks for each member, such as an 'overseer' type role to ensure all remain engaged.
• Supportive presence upon the wiki by lecturer commentary now and then, for example in response to progress, to 'name check' and informally recognise each individual student's participation at some point, and to keep the discussion moving.
• Commencement of the wiki project within the classroom, such as during on-campus tutorials or online Elluminate sessions. Teams may be assigned and group member introductions made at this point, enabling groups to break the ice and get the ball rolling. Many students have never collaborated at all on university assignments before, much less within an online environment, and may need support to become comfortable within these new virtual classrooms.
• Reserving more ambitious wiki projects for higher level undergraduate or postgraduate courses, as more experienced and potentially elder students may be more likely to assume greater responsibility for equal and consistent contribution, and more reliable application to task. (Elgort, Smith, & Toland, 2008).

Student unfamiliarity with digital tools and online environments

Becoming wholly au fait with just one web 2.0 tool can be hard work, especially taking into account the need to stay abreast of its evolution and status in the'survival of the fittest' environment of social media. For those who grew up in a world in which telephones were hardwired to walls, and tweets were emitted only by a passing sparrow, adaptation to this semi-virtual world may present a daunting challenge, one that is made no easier by the constant shifting of the goal posts as social networking technologies constantly morph and shapeshift. This less technologically savvy group may include not only the expected mature age students, but also younger people, those of different cultures where social media may not be as prevalent, and almost certainly a good percentage of the educators (as discussed below)!

• Create video 'tours' of the wiki by desktop sharing, and also link to other resources which may help, such as third-party YouTube demonstration videos, or host website Help pages. For example, this wiki is hosted upon the Wikispaces system, which provides searchable support system with contact facilities for personalised assistance here.
• Making careful choices about the technologies used, such as utilising the wiki service which seems clearest and most intuitive to use, and which can achieve all goals in one place.
• Avoiding overload by using a limited amount of web 2.0 tools in course facilitation, and if possible introducing these at different stages in the course. The matter of avoiding cognitive load by not over-integrating other tools within the wiki is applicable here too.

Educator unfamiliarity with digital tools and online environments

Many educators undertook their own studies in a very different environment to that which todays students experience, and familiarisation and confidence with web 2.0 and other technologies is imperative not only to be able to relate to the university students experience, but to simply be able to perform well in course facilitation. Lecturers need to use technology throughout course facilitation, as when managing the learning management system, presenting on- and off-campus lectures and tutorials, participating in or hosting video conferences or Elluminate sessions, and when providing support to the students who themselves are likely new to these applications. This growing use of social and collaborative technologies in higher education has caused a kind of Darwikinian evolution of teaching practice, creating pressure upon teachers to adapt or become extinct. The best response is a proactive one:

• Proactively seek training in applications to become confident and skilled in their use. Many informal and formal training courses and tutorials exist, and institutional teaching support services will be able to recommend in-house or other avenues for training.
• Join or establish a network of educators in which to seek support, tips, and mentoring such as discussed upon the previous page.
• View others' course facilitation methods, and if possible observe as these are established and set up. Whether a particular tool is currently needed for course facilitation or not, have a play and create a mock wiki for a course, or replicate another lecturer's use of these tools.

Educator participation within wikis and online environments established for teacher education and support may encounter issues as well; possible causes may include discordance between institutional philosophies and politics, and those of a particular wiki; lack of a cogent point of focus of the wiki, with the lack of direction resulting in a lack of guidance in starting a discussion; discomfort in adding to or altering others' ideas and contributions, or the presence of too many variances in teaching contexts for relevant advice to be available; and a simple lack of familiarity and with this new form of teacher education. By considering each of these potential pitfalls before creating or joining an educational wiki they may be accounted for and avoided. (Brass & Mecoli, 2011).

Next: Web 2.0 Glossary.

Brass, J., & Mecoli, S. (2011). The (failed) case of the Winston Society wikispace: The challenges and opportunities of web 2.0 and teacher education.Contemporary Issues in Technology and Teacher Education, 11(2), 149-166.

Choy, SO. & Ng, KC. (2007). Implementing wiki software for supplementing online learning. Australasian Journal of Educational Technology, 23(2). Retrieved from http://www.ascilite.org.au/ajet/ajet23/choy.html

Elgort, A., Smith, A., & Toland, J. (2008). Is wiki an effective platform for group course work? Australasian Journal of Educational Technology, 24(2), 195-210.

Judd, T., Kennedy, G., & Cropper, S. (2010). Using wikis for collaborative learning: Assessing collaboration through contribution. Australasian Journal of Educational Technology, 26(3), 341-354.

Witney, D., & Smallbone, T. (2011). Wiki work: Can using wikis enhance student collaboration for group assignment tasks? Innovations in Education and Teaching International, 48(1), 101-110.