This article gives a fair and unbiased explanation on the validity of handwriting analysis. If you would like to know exhaustively about graphology, then refer to the resources mentioned at the end of this article.
What precisely can our handwriting reveal about us? So much more than you might think. Jacob J. Cammarata explains the process well in his book Handwriting Analysis: Laws/Principles - and More.
It is a proven fact that handwriting analysis is an important diagnostic tool to evaluate an applicant's personality traits. The data submitted by a graphologist is very useful in choosing the right candidate for specific job roles.