Different Outcomes Require Different Explanations

Why Measure Performance? Different Purposes Require Different Measures

measures are worthless. To use a performance measure—to extract information from it—a manager needs a specific, comparative gauge, plus an understanding of the relevant context. A truck has been driven 6.0 million. Six miUion what? Six million miles? That's impressive. Six million feet? That's only 1,136 miles. Six million inches? That's not even 95 miles. Big deal—unless those 95 miles were dr...

Why different projects require different development methodologies . December 2002

Neural networks: different problems require different learning rate adaptive methods

In a previous study, a new adaptive method (AM) was developed to adjust the learning rate in artificial neural networks: the generalized no-decrease adaptive method (GNDAM). The GNDAM is fundamentally different from other traditional AMs. Instead of using the derivative sign of a given weight to adjust its learning rate, this AM is based on a trial and error heuristic where global learning rate...

Comparing Different Explanations of the Volatility Trend

We analyze the puzzling behavior of the volatility of individual stock returns over the past few decades. The literature has provided many different explanations to the trend in volatility and this paper tests the viability of the different explanations. Virtually all current theoretical arguments that are provided for the trend in the average level of volatility over time lend themselves to ex...

Different Placebos, Different Mechanisms, Different Outcomes: Lessons for Clinical Trials

Clinical trials use placebos with the assumption that they are inert, thus all placebos are considered to be equal. Here we show that this assumption is wrong and that different placebo procedures are associated to different therapeutic rituals which, in turn, trigger different mechanisms and produce different therapeutic outcomes. We studied high altitude, or hypobaric hypoxia, headache, in wh...