Justin posted this to the Hexawise Twitter feed

You enter a dark cave for the 1st time with a flashlight and you have 5 minutes. How do you use your time?

It sparked some interesting and sometimes humorous discussion.

The parallels to software testing are easy to see. In order to learn useful information we need to understand what the purpose of the visit to the cave is (or what we are seeking to learn in software testing). Normally the most insight can be gained by adjusting what you seek to learn based on what you find. As George Box said

Always remember the process of discovery is iterative. The results of each stage of investigation generating new questions to answered during the next.

Some "software testing" amounts to software checking or confirming that a specific known result is as we expect. This is important for confirming that the software continues to work as expected as we make changes to the code (due to the complexity of software unintended consequences of changes could lead to problems if we didn't check). This can, as described in the tweet, take a form such as 0:00 Step 1- Turn on flashlight with pre-determined steps all the way to 4:59 Step N- Exit But checking is only a portion of what needs to be done. Exploratory testing relies on the brain, experience and insight of a software tester to learn about the state of the software; exploratory testing seeks to go beyond what pre-defined checking can illuminate. In order to explore you need to understand the aim of the mission (what is important to learn) and you need to be flexible as you learn to adjust based on your understanding of the mission and the details you learn as you take your journey through the cave or through the software. Exploratory software testing will begin with ideas of what areas you wish to gain an understanding of, but it will provide quite a bit of flexibility for the path that learning takes. The explorer will adjust based on what they learn and may well find themselves following paths they had not thought of prior to starting their exploration.

Related: Maximizing Software Tester Value by Letting Them Spend More Time Thinking - Rapid Software Testing Overview - Software Testers Are Test Pilots - What is Exploratory Testing? by James Bach