Washington-based correspondent covering campaigns and Congress. Previously posted in Rio de Janeiro, Sao Paulo and Santiago, Chile, and has reported extensively throughout Latin America.

Control theory is a branch of mathematics and engineering, which defines the conditions needed for a system to maintain a controlled output in the face of input variation. Classically developed ...

But glosses wipe off easily, lipsticks get crusty, etc. So naturally, I was intrigued by the idea of a magical lip stain with seemingly eternal staying power in lieu of carrying around four lip ...

Should you paint or stain your kitchen cabinets? What about that dresser or set of bar stools you picked up at the thrift shop that's in dire need of renovation? Technically, either one will work, ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Louisiana students ...

Once people could trust that free and fair elections would be held regularly, the theory went, other forms of politics would come to seem too costly and violent to consider. The past decade has ...

Widely regarded as one of the most influential management experts in the early days of classical management theory, Mary Parker Follett used psychology and human relations within industrial management ...

In this article, you’ll gain a complete understanding of basic Piagetian theory and the strong body of experimental evidence supporting its application. Before you continue, we thought you might like ...

Management theory conceptualizes tools, frameworks and guidelines to motivate employees and accomplish goals. Frederick Taylor, an American mechanical engineer in the late 1890s and early 1900s, ...

The theory of human capital is relatively new in finance and economics. It states that companies have an incentive to seek productive human capital and to add to the human capital of their ...