In any case, earlier calculations depended on an even greater amount of guesswork.

It's like all knowledge. It's conjectural, guesswork, tested by observation, not derived from it.

There is guesswork involved, but at least it s been done in a systematic way.

As a result, emergency relief evaluations often rely on little more than guesswork and assumptions.

And in this way, you can take the guesswork out of policy making by knowing what works, what doesn't work and why.

Bearing in mind the uncertain variables just mentioned, providing a current estimate as to the conclusion of the Tribunal's work still remains an exercise in guesswork.

In May 2005, the previous President reported to the Security Council that giving an estimate at that stage of when the Tribunal will finish its work was an exercise in guesswork.

Alleviating poverty is more guesswork than science, and lack of data on aid's impact raises questions about how to provide it. But Clark Medal winner Esther Duflo says it's possible to know which development efforts help and which hurt by testing solutions with randomized trials.

But any assessment of North Korea s intentions at this point is mere guesswork, and the release of one detainee does not make for convincing evidence. What is certain is that the absence of any sustained meaningful dialogue with North Korea is a source of serious concern.