Premise:
"He notes that contributions might jump if campaigns used innovative approaches--the PBS donor model, for example, in which campaigns offer donors incentives, such as a T-shirt or a mouse pad featuring the candidate's likeness or slogan."
Hypothesis: The PBS donor model is one of the most successful models to date.

it is not possible to tell

Premise:
"His fat serpentine strokes and lacquer-smooth planes twisted around each other, arriving at exuberant new combinations that sometimes echoed his old friend Arshile Gorky as well as Henri Matisse and Piet Mondrian, painters whose final work was similarly buoyant."
Hypothesis: He was a painter whose work was exuberant and buoyant.

yes

Premise:
"The Sai Routha stood as well, his head dipped."
Hypothesis: He was ashamed.
it is not possible to tell