Rules (however arbitrary) tend to make things more interesting. We recently discussed why Ninja Post limits threads to 500 posts. In short, the goal with this design decision is to limit “content sprawl” and keep threads in a format that is easy for users (both old and new) to digest.

In addition to limiting the size of a thread, we have found that automatically archiving older content ensures that things stay fresh and interesting. This approach fits with our broader goal to keep Ninja Post fast, easy to use, and fun for users. While resurrecting an old thread can makes sense in some instances, bumping antiquated threads is generally frowned upon by users within a community. It is usually more effective to create a new thread.

The concept of setting limits to enhance usability is a popular technique used in countless scenarios. Would basketball or football or soccer be as intriguing if their respective fields had no boundaries? Most certainly not. Although Ninja Post permits significantly more leeway than Twitter’s 140-character limit or the three lines and 17 syllables of a haiku, we believe that providing some structure and some limitations ultimately has a positive impact on usability because it ensures content stays relevant and fresh.

As a follow up to last week’s post “5 Reasons Why Pagination Makes Sense For Forum Threads” it bears mention that there are instances where infinite scrolling does indeed make sense for forum software. The key distinction between when infinite scrolling is appropriate and when it is not depends on whether or not the user is actively and closely engaged with the content or if the user is simply browsing the content, looking for something interesting.

When deciding if infinite scrolling is appropriate, here is a general rule of thumb: if the user can lean back in his or her chair and scan content until something catches his or her eye, infinite scrolling is appropriate. By contrast, if the user needs to lean forward to engage with the content and pay close attention, then traditional pagination is a better choice.

Reading large amounts of text on a computer screen usually requires this “lean forward” posture, and forum threads typically contain a large amount of text. The need for sustained and enhanced focus to read a thread is simpatico with the benefits that pagination provides for dealing with a large volume of content that often unfolds in a narrative form. However, there are instances where infinite scrolling is appropriate for forum software:

1. When the user is scanning the list of threads for something interesting.
2. When the user is scanning the community’s photo gallery.
3. When the user is scanning lists of users (e.g., popularity rankings)

With Ninja Post, we prefer to use ‘Show More…’ buttons to load in new content in situations where infinite scrolling could be appropriate. This approach allows us to quickly add fresh content to the page when the user commands it but mitigates some of the drawbacks of infinite scrolling.