Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Valuable information - insightful essays

Not your everyday book on Outsider Art. While most art books on this subject just showcase collectors' investments, Testimony includes critical studies on the ways collections have been organized and new historical information about the relationship between African American vernacular art and the Outsider movement. All of the essays address hard questions and give you something to think about. In a field noted for its ugly politics, collectors Ronald and June Shelp have been brave and responsible in supporting this kind of writing.