Houston ISD APPRAISAL SYSTEMS ANNUAL UPDATEPDASMPDAS2009 -2010. NORMS. . . Silence PDAsListen activelyParticipate fullyAsk questionsMaintain safe learning environmentTake care of your needs. Objectives. . . To refresh our understanding and application of the Texas appraisal system as we apply it in Houston ISD To fulfill state requirements of providing an annual PDAS/MPDAS update To be aware of the 2009-2010 Board approved local calendar and policies..