The Art of Software Testing, Second Edition

3.6. Desk Checking

A third human error-detection process is the older practice of desk checking. A desk check can be viewed as a one-person inspection or walkthrough: A person reads a program, checks it with respect to an error list, and/or walks test data through it.

For most people, desk checking is relatively unproductive. One reason is that it is a completely undisciplined process. A second, and more important, reason is that it runs counter to a testing principle of Chapter 2—the principal that people are generally ineffective in testing their own programs. For this reason, you could deduce that desk checking is best performed by a person other than the author of the program (e.g., two programmers might swap programs rather than desk check their own programs), but even this is less effective than the walkthrough or inspection process. The reason is the synergistic effect of the walkthrough or inspection team. The team session fosters a healthy environment of competition; people like to show off by finding errors. In a desk-checking process, since there is no one to whom you can show off, this apparently valuable effect is missing. In short, desk checking may be more valuable than doing nothing at all, but it is much less effective than the inspection or walkthrough.