Effect of combining data on network topology. Average value of k1 as a function of k0 displayed on a log.-log. scale for the network composed of essential yeast genes. In each case, where the dataset includes information derived from protein complex analysis pair-wise interactions are determined using the spoke model. Green: network resulting from the incorporation of all protein interactions not classified as being obtained in "small-scale" studies. Brown: network resulting from the protein complex study performed by Ho and co-workers . Purple: network resulting from Y2H interactions identified by Ito and co-workers . Note that the relatively strong negative correlation present within the two networks generated using data from individual high-throughput studies (brown and purple on the graph) is significantly reduced when all available high throughput data are combined (green).