Comprehensiveness is the extent to which a source provides a complete and balanced view of a subject. Like timeliness, the importance of comprehensiveness varies according to the demands of your writing situation. If you are working on a narrowly focused project, such as the role played by shifts in Pacific Ocean currents on snowfall patterns in Colorado last winter, comprehensiveness in a source might not be important — or even possible. However, if you are considering a broader issue, such as the potential effects of global climate change on agricultural production in North America, or if you are still learning as much as you can about your subject, give preference to sources that provide full treatment.