How many crowdsourced workers should a requester hire?

How many great earthquakes should we expect?

G reat earthquakes of magnitude 8.5 or larger occur infrequently. For a nearly 40-y period after the February of 1965 M 8.7 Rat Islands, Alaska earthquake, the world did not experience a single great earthquake; however, in the 7 y since late December of 2004, there have been a barrage of five great earthquakes. These earthquakes include the 2004 M 9.1 Sumatra, Indonesia earthquake; the 2005 M ...

How many scientific papers should be retracted?

In European research today, mobility has become firmly entrenched as a pre requisite for a successful scientific career; however, the reasons behind this emphasis on scientific nomadism are far from obvious. It is all too common for science policy-makers and funding bodies to extol the seemingly endless virtues of mobility, but it nearly amounts to heresy to ponder the possibility that a move a...

How many doctors should Sri Lanka have?

How Many Streamlines Should I Use?

Introduction In probabilistic streamline tractography, the choice of the number of streamlines to use is the source of much confusion. It is known that in order to sufficiently sample the voxelwise fibre orientation distributions so that a reasonable picture of the network of connections can be delineated, some minimal number of streamlines must be used [1]. But without a handle on the effects ...

How Many Bins Should Be Put in a Regular Histogram

Given an n-sample from some unknown density f on [0, 1], it is easy to construct an histogram of the data based on some given partition of [0, 1], but not so much is known about an optimal choice of the partition, especially when the set of data is not large, even if one restricts to partitions into intervals of equal length. Existing methods are either rules of thumbs or based on asymptotic co...