How Did It All Start?

The story behind World Tester's Day started when Grace Hopper, a computer scientist at Harvard University, was hard at work on the Mark II Calculator (designed by Howard Aiken). Hopper and her team discovered that the Mark II Calculator was delivering consistent errors. When they opened up the computer and looked into its hardware, they found an actual bug!

This bug, a moth, was stuck between the two solenoid contacts of the electromechanical relay and disrupted the electronics of the computer. Hopper and her team then detailed the incident in the work log, pasted the moth there as evidence of a 'bug,' and referred to the action of eliminating the error as 'debugging'.

From Turing to Hetzel – The Software Testing Evolution

Tests back then focused more on the hardware as its reliability was crucial to the proper functioning of the software. The focus on testing continued as computer science progressed.

Then in 1949, Alan Turing came up with the Turing Test. This test explained how software must adapt to the requirements of a project. It detailed that a machine's or a reference system's (logic) behavior must be indistinguishable. The focus on testing continued to improve software outcomes as this field marched on its path of progression. Then in 1957, Charles L Baker spoke of the importance of test development as more expensive and complex applications were developed. Baker spoke of the importance of designing tests that ensured that the software met pre-defined requirements. He also spoke of identifying ways to improve program functionality through debugging.

Later in 1979, Glenford J. Myers introduced a radical change in the procedure to detect faults in a program. Meyers said, "Software testing is the process of running a program with the intention of finding errors."

His concern was that to demonstrate that the program was flawless, testers could subconsciously select test data that had a low probability of causing program failures. To alleviate this, he focused on changing the goal. Instead of trying to prove that the program was perfect, he tried to demonstrate that the program was flawed. By trying to 'break the program' they would inevitably move towards greater software quality.

1983 saw testers integrate analysis, revision, and testing activities during the software life cycle to improve testing and, consequently, development outcomes. It was in 1988 that William Hetzel refined the concept of software testing and published the article "The Growth of Software Testing." Here, he redefined the concept, purpose, and methodology of testing.