Guidelines: ConsistencyConsistency can be defined as maintaining the same style or pattern throughout a work or among works. It can also be looked at as the absence of unnecessary complexity and is thus closely related to simplicity. Consistency has long been an important characteristic of hard copy (i.e., printed on paper) books. For example, most printed books maintain an internal consistency with regard to margins, fonts, page length, indentation, headings, writing style and colors (e.g., for text and backgrounds). This importance of consistency in printed books is a result of the major role that it plays in usability, perceived quality and credibility. Consistency can make information easier to find and understand; it has also been said that there is a natural human craving for consistency (just as there is for rhythm and rhyming in poetry and rhythm and melody in music). Usability refers to the efficiency, comfort, safety and satisfaction with which a wide range of people and under a variety of conditions can perform their tasks with a product. Considerable effort (e.g., years of research and writing) and expense is usually required to create and publish a high quality hard copy book. Thus it is clearly in the best interests of the author and publisher to devote some extra effort to ensuring a high degree of consistency in order to maximize its perceived quality and credibility and thus maximize its chances for market success. In addition to deliberate efforts, consistency in hard copy books is also a consequence of the nature of the book production process. For example, the process results in uniformity of pages and page color unless special efforts are made to do otherwise. Traditional typesetting processes have also dictated uniformity of margins and ink colors for the text (although more modern, electronic production processes have made it easy to change these). Consistency for content-rich web sites is no less important than that for hard copy books. Yet, it has been a major problem for the web, and there are countless examples of sites which are lacking in it, either at the more obvious levels (e.g., different background colors or designs for different pages for no apparent purpose) or at the more subtle levels (e.g., variations in writing style or in navigation without good reason). The frequent lack of consistency in web sites occurs because the factors that enforce consistency for hard copy books are absent (i.e., the book printing and binding technology) or greatly diminished (i.e., the economics of book production). That is, there is no cost, at least in terms of site production, of creating inconsistency; rather, there can be a large cost, in terms of time and effort, in trying to make a site consistent. The fact that there is no massive cost of production and distribution for a publisher (at least as compared with a printed book), with the consequent risk of massive losses should a site fail to attract a lot of users, means that there is much less incentive for a publisher, if there is one, to go to all the effort to try to make a site consistent. Moreover, there are added facets of web sites, which do not exist for hard copy books, for which it is necessary to make a conscious effort in order to achieve consistency. They include navigation, URLs, page names, page width and encoding in HTML (hypertext markup language). Consistency is fundamental to the LINMO concept because of its goal of making content as useful to as many people as possible. The LINMO guideline for consistency is very simple: it is that it should be applied consistently to every aspect of a site, including (1) the organization of information, (2) content (e.g., lack of conflicting statements), (3) writing style (e.g., language and dialect, level of formality, definitions), (4) page design (e.g., margins, columns, colors, fonts, headers and footers), (5) navigation (including links), (6) URLs, (7) naming of pages, (8) definitions and (9) page encoding. The only exceptions should be those situations in which their is some clear benefit to being inconsistent. The most obvious of these situations is with regard to page length, as variable lengths are a key part of the LINMO model and make possible substantial advantages for the web as compared with the fixed lengths of pages in hard copy books. Another, very obvious, example of a well justified exception is the variability of chapter lengths in hard copy books. Both hard copy books and LINMO-compatible sites, however, maintain consistency with regard to page width1. The former is, of course, due to the physical nature of paper pages and the book production process. Regarding the latter, the width is consistent in the sense that it is designed to automatically be identical to the width of any display screen, rather than a fixed number of pixels (i.e., the small dots of which screen images are composed) as in encountered on some web sites. The use of HTML code to make page width automatically adjust to the screen width adds greatly to the usability of sites for users who access the sites with computers or other devices having small screens. Consistency is not at all incompatible with creativity. In fact, it can be argued that consistency actually facilitates creativity by allowing authors and users to focus on what is really novel and unique rather than being distracted by random and meaningless (and often unattractive) variations. Although the guideline for consistency itself is very simple, attaining it can be difficult, particularly on subtle levels. It can require considerable experience, and it is probably as much of an art as it is a science, especially in situations in which it appears that some difficult compromise might be required.
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Created May 8, 2006. |