History

The separation of debugging from testing was initially introduced by Glenford J. Myers in 1979. Although his attention was on breakage testing it illustrated the desire of the software engineering community to separate fundamental development activities, such as debugging, from that of verification. Drs. Dave Gelperin and William C. Hetzel classified in 1988 the phases and goals in software testing as follows:

until 1956 it was the debugging oriented period, where testing was often associated to debugging: there was no clear difference between testing and debugging. From 1957-1978 there was the demonstration oriented period where debugging and testing was distinguished now - in this period it was shown, that software satisfies the requirements. The time between 1979-1982 is announced as the destruction oriented period, where the goal was to find errors. 1983-1987 is classified as the evaluation oriented period: intention here is that during the software lifecycle a product evaluation is provided and measuring quality. From 1988 on it was seen as prevention oriented period where tests were to demonstrate that software satisfies its specification, to detect faults and to prevent faults.

Dr. Gelperin chaired the IEEE 829-1989 (Test Documentation Standard) with Dr. Hetzel writing the book The Complete Guide to Software Testing. Both works were pivotal in to today's testing culture and remain a consistent source of reference. Dr. Gelperin and Jerry E. Durant also went on to develop High Impact Inspection Technology that builds upon traditional Inspections but utilizes a test driven additive.

White-box, black-box, and gray-box testing

White box and black box testing are terms used to describe the point of view a test engineer takes when designing test cases. Black box testing assumes an external view of the test object; one inputs data and one sees only outputs from the test object. White box testing provides an internal view of the test object and its processes.

In recent years the term gray box testing has come into common usage. The typical gray box tester is permitted to set up or manipulate the testing environment, such as by seeding a database, and can view the state of the product after his actions, such as performing a SQL query on the database to be certain of the values of columns.

Gray box testing is used almost exclusively by client-server testers or others who use a database as a repository of information, but can also apply to a tester who has to manipulate input or configuration files directly, or perform testing like SQL injection. It can also be used by testers who know the internal workings or algorithm of the software under test and can write tests specifically for the anticipated results. For example, testing a data warehouse implementation involves loading the target database with information, and verifying the correctness of data population and loading of data into the correct tables.