Reading/Web/Desktop Improvements/Features/Limiting content width/zh

本项目的主要目标之一是使维基百科和其他维基媒体的维基更加欢迎新来者. 我们的其中一个目标是让阅读文章的体验更舒适.

什么是舒适（或不舒适）的阅读体验？根据研究，有几个促成因素，其中一个主要因素就是行长. IBM高级学习中心Peter Orton博士的研究“计算机文本行长影响阅读和学习”的结论是，行长越长，某人阅读并最终学习且保留文本信息就越困难. 在维基百科的文章行长中可以找到其他一些相关的研究，所有这些研究都建议每行40到75个字符.

虽然在维基媒体维基上实现推荐的行长并不是特别容易，但我们将使用最大宽度来限制内容的宽度，以使维基上的大部分文字更接近推荐值.

你可以了解更多关于这个功能背后的研究和考虑.

发布计划
我们于2020年5月开始向办公维基（Office Wiki）和测试维基部署第一次变更，并计划在接下来的几个月中继续在我们的早期采用者维基部署. 有关更多详细信息，请参见我们的主功能页面.

功能描述及要求
The main functionality of this feature is to limit the width of the article content. However in order to ensure that the other elements on the page (namely the sidebar and header) don't drift too far from the content we've added two additional containers. The second container ensures that the sidebar remains close to the content. Then to protect against the header drifting too far from both the content and the sidebar, there is a third container that constrains the maximum width of the header.

From a technical perspective: the content on most pages is placed inside a content container with a max-width of 960px. There are two additional containers that help manage the width of other parts of the interface such as the header and the sidebar: workspace container (max-width 1440px), and page container (1650px). Below are diagrams that illustrates how these containers work. There are certain pages whose content will not be constrained by the content container including History, Recent changes, and other similar log-type pages. To explore an interactive demo of this feature please see this prototype.

设计要求及准则
Here is a GIF that illustrates the difference between the current layout and the updated layout with the various width limitations described above:

限制
The main complication here is that certain log pages, such as History and Recent changes, become more difficult to read the more narrow the screen is due to line wrapping. Therefore we've decided to treat these pages in a special manner, constraining them only to the workspace container (1440px) rather than the content container (960px). Here is a GIF of a prototype that shows switching between an article page and the associated history page:

使用编辑器进行用户测试
We performed a feedback round with a prototype of the limited content width with editors across multiple wikis. Editors were invited to explore the prototype and provide their feedback using a central notice banner. There were mixed feelings about the feature: many editors appreciated the shorter line lengths and agreed that the feature created a more comfortable reading experience. Some editors disliked the whitespace around the content and felt that it was wasted space. We are balancing all of that feedback with the extensive existing research about line-lengths and reading comfort.

可读性
The primary reason is to improve readability of Wikimedia wiki pages. So perhaps the first question is: how can we know what the optimal width of the content area is? There are research-based recommendations regarding optimal line lengths for readability of text, so we should probably start there. But then again Wikimedia wiki articles are different from common articles or web pages in certain ways. They are unique both in how long they are and in the variability of layout from one article to the next. Both of these factors may lead to a larger than usual need for scanning and searching for content (rather than linear reading). Our design must take into account these distinctions. We need to therefore ask, are Wikimedia wiki pages unique enough to warrant a line-length different from what is generally recommended? Below we explain how we’ve arrived at our design recommendation for what the max-width should be.

Without studying readability of Wikimedia wiki pages directly we can’t know what is optimal, but in an attempt to make an educated guess we start with the research on optimal line length for readable text. The research and recommendations in this area seem to be well established. The Wikipedia page on Line Length provides a good overview, as does the essay Size Matters: Balancing Line Length And Font Size In Responsive Web Design by Professor Laura Franz. The research study Computer text line lengths affect reading and learning by By Peter Orton, Ph.D. IBM Center for Advanced Learning is a more rigorous, academic study. The popular recommendation is that there should be between 40 and 75 characters per line. The findings of multiple studies conclude that "short line lengths are easier to read", and furthermore regarding learning and information retention "Subjects reading the narrow paragraphs had better retention than those reading the wide paragraphs". One can find many popular sites that conform to these guidelines. Articles on the online science journal Nature have a max-width resulting in ~76 characters per line, New York Times articles are ~64 characters per line, Times of India articles are ~100 characters (Hindi), Oxford Academic journal articles are ~75, and articles on the World Health Organization’s website are ~96 (Latin alphabet), ~46 (Chinese alphabet), and ~85 (Cyrillic alphabet). It is also worth noting that when using reading mode in Safari or Firefox text is rendered at ~73 and ~77 characters per line respectively (Latin alphabet).

In comparison, a Wikimedia wiki page on a browser window at 1280px* has a character count of ~170 characters per line, and that’s at the small end of the screen size spectrum. (*The most common computer screen size, accounting for 22% of users, is 1366px wide according to StatCounter; imagining a browser window at nearly full width you end up with ~1280px). Then factor in that on Wikimedia wiki the character count per line grows as the screen width grows (whereas on the other sites mentioned the character count per line remains the same, the result of max-width constraints). So on the second most popular screen-size, 1920px (21% of users), the character count per line is ~262 (again assuming a browser window at nearly full-width), more than three times the recommended value. So as a starting point we know that for paragraphs of uninterrupted text we are well over the recommended limit.

The question then becomes: why not limit the width of Wikimedia content such that we achieve the recommended line length, as other online content sites seem to? The short answer is: because our pages are different, and therefore people read them differently. Wikimedia wiki pages are very long, contain a large amount of information, and they are not uniform from one page to the next. As a result, people have a greater need to skim and search within pages than they would when reading a typical online article or book (this is supported by our research around reading time on Wikipedia). So while the line length recommendations provide a good starting point, we also must consider that the more narrow we make the content, the longer the page gets, and perhaps the more difficult scanning becomes (involves more scrolling, etc.) (for more information regarding different types of online reading please see this 2006 study conducted by the Nielsen Norman Group). Additionally, because Wikimedia wiki pages contain many elements that are floated inline alongside text it is not straightforward to achieve a specific number of text characters per line.

建立共同的阅读体验
The second reason we think introducing a max-width could be beneficial to the reading experience is because it would work towards establishing a common experience, which hopefully would be helpful to editors when making decisions about page layouts (note: 1024px is mentioned as a minimum size to consider in the WP:Manual of Style/Layout page, though that’s not quite the same thing). Currently an editor might be editing a page at a width of 1500px, while a reader reads it at a width of 1200px. By implementing a max-width we don’t remove this discrepancy completely (because there would still be variation below the fixed-width, for people with narrower screens), however we would be greatly limiting the range of variation.

结论
After thinking all of that through we’ve come to two conclusions:


 * 1) It seems that a max-width in the range of 800–1000px is a sensible starting point. We will center the content on the page to ensure that it looks good with the sidebar both open and closed.
 * 2) It seems worthwhile to conduct a study focusing on the readability of Wikipedia articles specifically. We hope to be able to find the resources to do this.

Breaking templates / content / special pages / etc.
Part of what makes Wikipedia, and other Wikimedia wikis, a powerful tool for sharing knowledge is that there are very few constraints on how information is presented. The result of this is a wide variety of different elements on the pages: tables, image galleries, diagrams, panoramic images, graphs, forms, maps, category boxes, and more. Having dealt with the challenges of designing the mobile site, and getting the content to look good, we recognize that there are going to be some situations where page content doesn’t look great given the max-with. Our plan currently is:


 * Work with our test Wiki communities to identify issues and discuss solutions using template styles or other existing tools.
 * Not to implement the max-width on Special pages. Special pages are not necessarily intended for “reading”, they often function more as lists or dashboards, and until we have time to work through the intricacies of more responsive layouts for these pages we will be leaving them alone. Here is an initial prototype of how this would work — you can switch between "View history" and "Read" to get a sense for it.

先前的讨论
This topic has been discussed in the past. Please feel free to add additional links to past conversations here.
 * 2014 – discussion from the Typography Refresh project