Before revision:  As one of the main results , we prove that dissimilarity allows for fixed-parameter tractability for the parameter solution size, thereby contrasting our W[1]-hardness proof of the corresponding similarity case  .
After revision:  As one of the main results , we prove that dissimilarity allows for fixed-parameter tractability for the parameter solution size, thereby contrasting our W[1]-hardness proof of the corresponding similarity case . We also provide partially positive results concerning efficient and effective data reduction (kernelization) .