Let V 0 denote the manually labeled documents, if the document expresses positive sentiment (V 0 ) ii = 1, and (V 0 ) i2 = 1 for negative sentiment.
the semi-supervised learning with lexical knowledge can be written as: where Tr(•) denotes the trace of a matrix, α > 0 and β > 0 are the parameters which control the contribution of lexical prior knowledge and manually labeled documents.