The Brattle Group has significant experience in the sampling and analysis of large and complex loan datasets. We have evaluated the characteristics of loans underlying the mortgage pools to understand the extent to which loan pools have been concentrated in certain geographic areas, among certain types of borrowers, and with specific types of loans. These loan attributes include: the geographic distribution of collateral; seniority (e.g., first or second lien); LTVs or CLTVs; amortization schedule (e.g., fixed rate, ARM, Option ARM); and borrower creditworthiness.