"Dabble" in a positive sense

Dabbled in carries a not negative connotation, but a somewhat dismissive tone. As in, "I dabbled in witchcraft and it wasn't for me." Dabbling doesn't have a sense of permanency to it in terms of one's interest in a matter. That said, "I dabbled in novice physics books and am a bit wiser for the effort" would certainly bear a positivity about it.

Mostly, it just depends on how one extends or qualifies the impact of dabbling. Dabbling seems to have a certain antecedent>consequent structure to it that implies the positive/negative; i.e. with both example phrases above there is no +/- value until the "and..." statement created one.

In BE it is a positive sense - to dabble in something is gentlemanly.
Only a foreigner would need to exert themselves.

(The above may account for Britain's expected performance in a certain sporting event to be held in London in 2012)