- Ground-motion model is:
where v = 0 for horizontal and 1 for vertical.

- Response spectral parameter is pseudo-velocity for 5% damping.
- Use records from stiff soil/rock sites.
- Focal depths between 15 and 122km.
- Use square-root-of-sum-of-squares (SRSS) to combine horizontal components to reduce strong azimuthal dependence of ground motions. Note that dividing predicted spectra by 1.41 gives spectrum for each component separately.
- Do not derive equations for T > 1s because of baseline problems and noise in accelerograms at longer periods.
- Try more complex functional forms but not enough data to constrain all parameters to physically-realistic values.
- Smooth coefficients using unspecified technique.
- Report residual spectra for different probability levels not σ.