Proven vs. Proved

[Prezbucky]

"The method has proven successful."

"The method has proved successful."

Is there an unequivocal rule dictating which of these is correct?
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Billie Jean is not my lover. Hee.

[Pond969]

There is no unequivocal rule as such. The former construction suggests a method that has consistently and repeatedly been successful over time, while the latter would suggest only that a recent test, or limited number of recent tests, of the method was successful.

'Proven' suggests something conclusive and final, whereas 'proved' would typically convey the notion that the method has so far been successful but that perhaps there could still be room for more testing.

[Prezbucky]

danke

...so they're both used, but in different circumstances.
_________________
Billie Jean is not my lover. Hee.