“Testing is the process of evaluating a product by learning about it through exploration and experimentation, which includes: questioning, study, modeling, observation and inference, output checking, etc.”
Where does scripted testing fit, then? By “script” we are speaking of any control system or factor that influences your testing and lies outside of your realm of choice (even temporarily). This does not refer only to specific instructions you are given and that you must follow. Your biases script you. Your ignorance scripts you. Your organization’s culture scripts you. The choices you make and never revisit script you.
By defining testing to be exploratory, scripting becomes a guest in the house of our craft; a potentially useful but foreign element to testing, one that is interesting to talk about and apply as a tactic in specific situations. An excellent tester should not be complacent or dismissive about scripting, any more than a lumberjack can be complacent or dismissive about heavy equipment. This stuff can help you or ruin you, but no serious professional can ignore it.
Are you doing testing? Then you are already doing exploratory testing. Are you doing scripted testing? If you’re doing it responsibly, you are doing exploratory testing with scripting (and perhaps with checking). If you’re only doing “scripted testing,” then you are just doing unmotivated checking, and we would say that you are not really testing. You are trying to behave like a machine, not a responsible tester.
ET 3.0, in a sentence, is the demotion of scripting to a technique, and the promotion of exploratory testing to, simply, testing.