You can always leave, during or after the probation period, given that you fulfill some contractual requirements (like telling them some weeks in advance, see your contract). Employment is no prison. For more information, see http://en.wikipedia.org/wiki/Probation_%28workplace%29
Screening is conducted to identify or predict students who may be at risk for poor learning outcomes. Universal screening assessments are typically brief, conducted with all students at a grade level, and followed by additional testing or short-term progress monitoring to corroborate studentsâ risk status.
A screening by definition has to be relatively quick, easy to implement and have to have relative good sensitivity and specificity to try to identify those individuals who are potentially at risk for the problem. And the diagnostic evaluation has multiple components.