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Case-study: Is letter frequency analysis a guide to authorship?

Taking and analysing a sample text from two different authors can the derived frequencies be used as a guide to authorship of a third text?

The samples are Author A, Author B, and Test Text. For an additional comparison a third text, by Author NS, is included. The Author A text has 668,187 alpha-characters, the Author B text 332,226, the Test Text 753,531, and the NS text 698,782.

This graph shows the difference between 'expected' letter frequencies in English (E) and each of the sample texts (A, B, and NS).

Chart freqa author e01.gif


This graph shows the difference between the test text (T) and the sample texts (A, B, and NS). The correlation T-A is 0.998822, T-B is 0.993758, and T-NS is 0.992641 (T-E is 0.99769).

Chart freqa author t01.gif

The texts are:

The Empty Battlefield is a term used to describe the impact of technology on modern conflict.

The prime agent of change was gunpowder, although the rate of change was uneven. From the great change in Europe in the late 16th into the 17th century, when almost every standing (European) army adopted firearms. The tactical move from the Swiss pike square to the Piedmont Band to the tercio to the formations of Maurice of Nassau and Gustavus Adolphus, were each marked by an increasing number of hand-guns and artillery. The introduction of the socket bayonet (1680s), replacing the plug bayonet (1630s), ended the need for any pikemen.

The technological changes in firearms were also marked by a reduction in individual skill. The requirement of years of experience to wield a weapon effectively slowly vanished. Each developed (matchlock to flintlock; breech-loading to bolt-action) reduced the drill to load and fire a weapon, while other changes improved accuracy. An army could be thus assembled from quickly-trained conscripts not professionals, allowing much larger forces to be fielded and also reducing the individual value of soldiers - the loss of life in a major battle could now be quickly replaced so commanders were more eager to engage the enemy.

Guns spread the battlefield both in width and, especially, depth. The lethal range of a cannon's shot defined the limits of the battle rather than the spear or arrow of early conflicts. As the field spread vision was diminished, both by terrain and the smoke and dust raised. The 'fog of war' on a smaller scale.

In order to survive infantry formations, tactics and equipment had to change. There was considerable resistance to this for a number of reasons.

Until the 20th century most gunpowder armies retained variations on ancient formations. They marched in column and deployed in ranks and lines. The mass formations reinforced the mechanical actions of loading and volley fire. The serried ranks also created 'solidarity' in the formation, a soldier stood with his comrades - gaining their support or suffering their approbation with his actions. Massed formations were also important to commanders. Large, visible groups could be given orders, and 'seen' to respond. It was also easier to maintain discipline. Colourful uniforms gave an imposing spectacle and imporved esprit de corps. There was a widespread contempt from commanders for their soldiers, if they were deployed in dispersed formation, it was claimed they would not advance, would not fight, and would be easy targets for cavalry.

That close-order formations suffered appalling casualties was obvious. Infantry exchanged fire at very close range, and the damage from artillery fire on these static formations was immense. But the mentality of (European) commanders demanded a rapid advance to close-quarters combat, without halting. Offensive spirit and morale were seen as the key determinants of a battle. Even the grim demonstrations of the American Civil War and the Franco-Prussian War were ignored. The success of the Japanese at Port Arthur was seen as a victory for high-morale infantry, rather than an example of the damage heavy artillery could do to fixed fortifications.

The defensive power of modern machine-guns, artillery and rifles was not hammered home until WW I.

The initial clashes were in an almost Napoleonic form - the belief was that a swift victory would go to the most aggressive force, that continued the attack regardless of casualties. The French army suffered 40% of its total wartime casualties in 1914.

This belief changed quite quickly, and many observers date 'modern war' to beginning in 1915 or 1916. Forced to dig to survive the rapidly spreading trench systems forced the war into an attritional conflict that was almost as costly as the blundering of 1914. "Firepower replaced manpower as the instrument of victory."

German system - defense in depth. Machine-guns. Individual initiative. Flexibility. Speed and suprise in attack -stormtroopers, Hutier. Momentum - infantry speed vs armour speed.

Allies - technological / mass production solution - "a demand for more"

The spade

A failure to embrace technological change was always, eventually, lethal.


After - return of professionals - complexity, technology