Fig 2. Ideological classification of the US Congress based on truth values.

(a) Ideological network of the 112th US Congress. The plot shows a subset of the WKG constituted by paths between Democratic or Republican members of the 112th US Congress and various ideologies. Red and blue nodes correspond to members of Congress, gray nodes to ideologies, and white nodes to vertices of any other type. The position of the nodes is computed using a force-directed layout [33], which minimizes the distance between nodes connected by an edge weighted by a higher truth value. For clarity only the most significant paths, whose values rank in the top 1% of truth values, are shown. (b) Ideological classification of members of the 112th US Congress. The plot shows on the x axis the party label probability given by a Random Forest classification model trained on the truth values computed on the WKG, and on the y axis the reference score provided by dw-nominate. Red triangles are members of Congress affiliated to the Republican party and blue circles to the Democratic party. Histograms and density estimates of the two marginal distributions, color-coded by actual affiliation, are shown on the top and right axes.