Wikipedia:Merge Test

When deciding whether to merge an article or not, answer the following questions:
 * 1. Will a merge result in an article that violates article size guidelines?
 * 2. Will a merge require the removal of encyclopedic content?

If you answered no to both questions, then a merge is acceptable.

If you answered yes to question 1 and/or 2, then a merge is not desirable.

Justification
Articles are frequently nominated for merging, and this test is designed to determine whether such a merge is desirable. According to Wikipedia's size guidelines, articles above 60,000 bytes should probably be divided into smaller articles. Obviously, a merge that exceeds this limit is generally undesirable.

During many merges, some content is not carried over to avoid the creation of overly large articles. The non-carried over content is in effect deleted. Often, the lost content is cruft- content that is so trivial that it is only of interest to a very small niche audience. Deleting cruft during a merge does not violate question number 2 as cruft is inherently non-encyclopedic. However, many pages contain information that is encyclopedic and is of actual use to a general audience. Carrying over all of this information during a merge will result in an article so large that it is unreadable. In this case, the article should be kept as is to preserve the encyclopedic content.

Even if deleting the encyclopedic content is permissible by policy, it is still a disservice to anyone who would have found the content useful. Merges that violate question 2 lower the quality of Wikipedia as a result.