Direct Manipulation Interface - Essay Example

Direct manipulation interface Direct manipulation is a mode of interaction between a user and a computer that allows the user to continuously give commands and receive feedback in the form of objects made to represent specific actions and reactions (metaphors) in the real world. This interaction allows for direct execution of actions by the user with the notion of not having an intermediary such as a menu or command assisting them thereby creating an environment of virtual reality. Direct manipulation interface is an advancement of the earlier version of interface called the command line or text interface that requires the user to literally key in commands in navigating the computer’s actions. The direct manipulation interface is a more efficient mode of interaction where the user points at metaphors on the computer and the commands given on their behalf, unlike the line command that requires them to key in the commands by themselves. Direct manipulation, being easier and faster at executing commands, is a preference of majority computer users today, especially designers and gamers as it supports the creation of virtual environments. A virtual environment is a simulation by means of a computer that creates a false or aped environment in which a computer user can perceive themselves in, and interact with objects in it (Montfort, Nick, & Noah 485). The direct manipulation interface has three main principles that make it a preference for a larger cross-section of computer users today. The first principle is the ability to virtually represent the objects of interest continuously in graphic forms and in almost real appearances. The other principle is the support of fast, reversible actions that are immediate and the last principle is the ability to directly manipulate a command on an object after using a pointing device to locate it. These principles are universal in that they are almost similar from system to system, therefore allowing frequent users to familiarize with, and use them anywhere. Application of direct manipulation interface in games Direct manipulation supports graphical representation of objects, an application extended and put to use in games, as they require simulation to create virtual environments that enable the user to perceive of them being in them. 3D renderings of virtual environments of action excite the user, further engaging them and letting them take roles and control avatars in games. The user interacts with virtual characters who act as drivers, players, dragons and so on in virtual environments with highways, hills, water, and fire. In order for the user to interact with the virtual characters and environments, they require game controls to direct their subjects. Direct manipulation enables the user to use buttons or other game controls and not type lengthy syntax commands. This makes the user enjoy the game without much cramming of commands. The game controls in the games give instructions or commands to the virtual objects or characters that result in rapid responses that prompt the user to correct their moves or perform moves that are more complex thus actively engaging in the virtual gaming (Montfort, Nick, & Noah 499). Types of game interfaces There are two types of game interfaces: three-dimensional and two-dimensional. 3-D game interface is the representation of geometric data in a form that has length, width, and height (has x, y and z-axes) such that it is visible from all perspectives and has the perception to hold mass. 2-D interface is a representation that displays graphics on a screen by use of pixel arrays. It has an X and Y-axis only (Cellary, Wojciech & Krzysztof 279). These two interfaces apply in gaming and computer aided design but are largely inapplicable in real life applications for several reasons. An example is in word processing or spreadsheet applications where using a 3-D interface will make it impossible or very hard to write and annotate. Another reason is that that due to the additional axis in 3-D models, it is difficult to pick and relocate the graphical representations and this will hamper the user who regularly moves them. Finally, when using 3-D applications, there is usage of more spatial memory than when using real life applications, translating to strain of the spatial memory available. Advantages of direct manipulation over line command interfaces The direct user interface is advantageous to the user in that it is easy to master, and once the users learns to use it, they gain confidence because they are the ones in control of the commands therefore can predict the outcomes. Line command interfaces demands that a user knows all the commands in integers that are a very complex procedure. Secondly, in the advantages of direct manipulation, users do not require the user to cram hundreds of syntax integers, rather, it represents them with metaphors and when the user points onto them, and the execution is automatic therefore resulting in less error messages. In the case of line commands, mistaking a simple syntax results in errors, malfunction, or loss of function. The biggest advantage of direct manipulation over line command interface is the ability to visually present task concepts. This has several advantages, for instance, the user gets motivation to explore the system more by following the set metaphors. In addition to his, the interface enables the user to execute complex applications like games and computer aided design. These are not possible with the line command interface that show text interfaces only and require lengthy codes to perform certain tasks, disabling tasks like design or games that require graphics (David 7). Direct manipulation interface: evaluation This interface is the most preferred one in the computer world today owing to its user-friendliness because it is easy to learn. Secondly, it has wide application support in that it can hold 3-D and 2-D programs. It also has most of its commands represented by metaphors relating to the tasks assigned meaning one encounters less errors. Direct pointing and commanding allows rapid irreversible actions so the user works faster and can correct any errors made. Multi-tasking support means the ability of the interface to hold several task windows at a go. In conclusion to its advantages, this interface has universal graphical task representation abilities meaning once the user learns to use one interface, the same knowledge is applicable elsewhere. However, it has its own disadvantages. For one, since it is a visual interface, blind users are not able to use it, as one needs to locate the metaphors to execute commands. Secondly, the design and inclusion of metaphors consume considerable space on the screen that could otherwise hold a task window. Third, it is impossible to use it if one does not have the knowledge of the meaning of the visual representations. Lastly, it may cost an inexperienced user more time in typing when they have to get their hands off the keyboard to control the mouse. Works cited Cellary, Wojciech, and Krzysztof Walczak. Interactive 3d Multimedia Content: Models for Creation, Management, Search and Presentation. London: Springer, 2012. Internet resource. David Frohlich.(1996) Direct Manipulation and Other Lessons. Retrieved on October 22, 2013 from http://www.hpl.hp.com/techreports/96/HPL-96-152.pdf Montfort, Nick, and Noah Wardrip-Fruin. The New Media Reader. Cambridge, Mass. [u.a.: MIT Press, 2003. Print. Read More