After more than five months of hard work, Robinson Crusoe realized that he could not launch his first canoe because it was too heavy and too far away from the stream. He wrote, "This griev'd me heartily, and now I saw, tho' too late, the Folly of beginning a Work before we count the Cost; and before we judge rightly of our own Strength to go through with it."
R package sem (version 0.9-21) by Dr. John Fox was applied. See "Structural Equation Modeling With the sem Package in R" for overview. A modified boot.sem is available to generate Reliability (R-square) and standardized coefficients.