While I absolutely agree with Val that using short sentences is important to create clear content--whether or not it will be translated, that's only one stepping stone on a path to creating clear, usable, and reusable content. At least equally important are the words in those sentences.
We're all aware that it is important to choose our words so that they accurately convey the intended meaning. Anyone with more than a cursory understanding of technical communication also understands that those words must be appropriate for the audience. Further, most technical communicators are aware that specialized audiences use and understand certain domain-specific vocabularies. However, it is possible to do a great job of choosing wording that conveys meaning, suits the audience, and uses the audience's specialized technical "language" to write effective text that is not particularly efficient.
Efficient Writing
There are many ways to increase efficiency in the writing process, such as writing structured, topic-based articles for reuse, using a content management system, and writing to standards. Perhaps the most important factor for efficiency in the writing product for global content is to use a controlled vocabulary.
Controlled vocabulary is not a new concept. Biologists, librarians, and programmers have long used limited vocabularies to refer to particular items, concepts, or structures in order to make them understandable across broad audiences. The classification system used for biological taxonomy is an example of a controlled vocabulary. There are many ways by which a dog may be described. The taxonomic system provides a common structure and a common vocabulary for such description. A dog breeder or a vet may use "Staffordshire Bull Terrier" to describe a breed. To a lay audience, "Pit Bull" may be a better descriptor. Indeed, using audience- or domain-specific technical terminology is an aspect of using a controlled vocabulary. To improve efficiency of text, this concept can apply to the the non-technical terminology as well.
Consider these sentences:
Define the hostname.
Identify the hostname.
Enter the hostname.
Now, enter the hostname.
Each of these sentences means the same thing. We could argue that "identify" and "enter" imply that the name already has been "defined," but will that level of precision be lost on your audience? Will your authors understand it and apply it consistently? The slight differences in wording in these four sentences would require four translations and, worse, could result in differences in meaning in the translated sentences. These inconsistencies in terminology would likely result in additional translation costs and other issues, as Val points out. Even without translation, a reader may waste time trying to determine the differences among these sentences or may interpret them differently. Efficiency requires consistency.
Controlled vocabulary is important not only for technical terminology but also for all terminology within your organization's technical content. Using a controlled vocabulary improves consistency, creates efficiency in the written product, and leads to more effective content.