The capabilities of nanoindentation to characterize low-k organo silicate glass (OSG) thin films is explored as a relatively rapid and inexpensive metric of mechanical properties, adhesion strength, and fracture toughness. One method of decreasing the static dielectric constant of OSG interlayer dielectrics requires the introduction of porosity in the material which has a dramatic impact on its mechanical and toughness properties. Percolation theory is used to formulate a correlation between porosity and elastic modulus. Using cube corner diamond indentation and scratch testing fracture toughness calculations are also discussed.