New techniques used in the study, such as using ultrasound to measure artery plaque, are generally difficult, and not as well understood as cholesterol lowering, they say.

FORBES: Magazine Article

Picking tops or bottoms is generally quite difficult as one often does not have clear technical divergences that can give them enough conviction and discipline to take a position.

FORBES: Finding High-Probability Entry Levels

Democrats generally do not like and do not support cuts in entitlement programs, and yet this President put forward difficult reforms in entitlement programs because he believes that you have to have a balanced approach, you have to include entitlement reform in any effort to reduce our deficit and bring down our -- reduce our debt.

WHITEHOUSE: Press Briefing

Third, the industry does not generally offer value-for-money products, but rather an array of proliferating instruments that are difficult to compare and understand.

ECONOMIST: Saving