This is not surprising since a small number of randomly chosen seeds provide much less information (corpus statistics) than high frequency seeds.
spectral's perfor- Medium Low All (spectral) 100 seeds 61.3 47.8 30.6 48.1 300 seeds 64.5 57.6 37.9 53.9 500 seeds 64.9 57.0 37.9 54.3 Figure 4: F-measure results (%) in relation to the choice of input vectors for spectral analysis.