Image tagging
For organizations that first digitize their assets, the initial problem of categorizing and identifying them becomes apparent. This is a time-consuming task requiring expertise and consistency. A digital object that has been incorrectly identified can be lost in the system. For organizations with hundreds of thousands of digital objects, the classification can become an expensive and difficult task to achieve.
The notion of image tagging has been around for some time. This involves a person adding a metatag and using it to identify the digital object (in this case, a tag is just shorthand for metatag). The tag is usually just one characteristic of the digital object and usually not a complete identification of the image (which would include author, security, copyright, and licensing). A tag might be an attribute, which lists all the items in a digital photo, or a set of words, that best describe the digital object.
Adding a tag in this case becomes useful when searching to find the digital object. One or two curators having to view, identify, and classify tens of thousands of digital objects are likely to make mistakes, as well as possibly introducing a bias into the tagging, resulting in the digital object becoming hidden.
To help overcome this issue, some businesses have opened themselves up to the general public and empowered authorized users to do the tagging for them. In such a case, all the curators need to do is to vet the results and verify that the descriptions provided are valid. It's much easier to validate a tag against a digital object than it is to do the tagging.
The challenge is to get people with sufficient skills to tag the images, while at the same time, ensure the digital objects are not vandalized or corrupted. Additionally, if users with insufficient skills badly tag images, this might result in more damage being done than if a curator tagged the image themselves. The idea of opening up the site to the general public and allowing them to add intelligence to the digital objects via tagging is a form of crowdsourcing.
Crowdsourcing
Crowdsourcing(18) is a distributed problem-solving and production model. In the classic use of the term, problems are broadcast to an unknown group of solvers in the form of an open call for solutions. With crowdsourcing, there is a balancing act between ensuring good quality data, ease of use, and recognizing correctly tagged values.
A well-structured computer system that manages the tagging and vetting can automatically track how well a user is doing with their tagging effort. Vetting is done under the assumption that it is easier to review a digital image and confirm that the tags are correct, versus the effort involved in determining what the tags should actually be. The vetting process involves a workflow for accepting a tag:
- The user attaches one or more tags to the digital object
- The digital object is the unmarked to be vetted
- A manager then reviews the tags against the digital object to verify that there is a match
- The digital object is marked as being vetted
- The new tags are made available for searching and reviewing
- The user is then informed of the result of the vetting
Crowdsourcing can be a useful technique for the translation of tags. An organization can request that a set of tags are translated into one or more languages. This technique is likely to produce better, more accurate results than attempting to use automatic translation through a Babel translation tool(19).
Gaming techniques
By adopting the competitive nature of some individuals and putting it into a constructive environment, a form of game can be formulated that not only encourages correct identification of an object but makes it fun for the person doing the tagging. This can result in a higher, more accurate throughput of the digital objects being tagged.
There is a cost involved in producing and maintaining the game versus doing the tagging manually. This cost has to be factored in to determine whether it is worthwhile doing it. Adding a game might also restrict the target audience, who will be willing to be involved in it. It might also give the appearance of cheapening the site. If the target group are teenagers to those in their twenties, the gaming aspect might make it more interesting to participate in, especially if there is a monitory prize involved.
To make the gaming site more attractive and competitive, leader boards can be set up, with even monetary or equivalent prizes given to the most successful taggers.
It's possible to adapt popular games to the tagging process. The space invaders game, which is well-known by most people, when adapted would have the aliens coming down equating to digital objects being tagged. If a user tags a digital object, the alien is destroyed. As it's a time-based game, the user is encouraged to not linger and tag as many images as possible. Like the word association game(20), the fast, spontaneous reaction to assigning tags could result in creative tag associations being formed.