## The Special Fish Report## Albert W. Small (December 1944)## Page 82 |
Tony Sale's Codes and Ciphers |

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odds that the unknown is also a dot are:

which equals 2 if b is 2/3, and thus 10Log10 = 3. Similarly if there are

three and four dots, given no crosses.

- In the example shown, the score values are given for crosses

in practice where it is not known whether or not the dots are really

dots, and the crosses crosses, there being a possibility that the signs

are reversed, but actually it is not correct. A complete and correct table

for scoring, assuming b = 2/3, follows:

- SCORES IN DECIBANS FAVORING HYPOTHESIS THAT

THE UNKNOWN IMPULSE IS A DOT (Relatively a dot)

Probability that

signs are the

right way round

.0 | .1 | .2 | .3 | .4 | .5 | .6 | .7 | .8 | .9 | 1.0 | |||

GIVEN: | SCORES: | ||||||||||||

.... | 3 | 4 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 12 | 16 | ||

... | 3 | 3 | 4 | 5 | 5 | 6 | 7 | 8 | 10 | 10 | 11 | ||

.. | 3 | 3 | 4 | 4 | 4 | 5 | 5 | 6 | 6 | 6 | 7 | ||

. | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | ||

xxxx | -16 | -12 | -10 | -9 | -8 | -7 | -6 | -5 | -4 | -4 | -3 | ||

xxx | -11 | -10 | -10 | -8 | -7 | -6 | -5 | -5 | -4 | -3 | -3 | ||

xx | -7 | -6 | -6 | -6 | -5 | -5 | -4 | -4 | -4 | -3 | -3 | ||

x | -3 | -3 | -3 | -3 | -3 | -3 | -3 | -3 | -3 | -3 | -3 | ||

any mixture | |||||||||||||

of dots and | |||||||||||||

crosses | 3 | 2 | 2 | 1 | 1 | 0 | -1 | -1 | -2 | -2 | -3 |

In the sample given, the ???? ".5" should have been employed if ignorance

was assumed.

- The above table is derived from the following formula:

probability of another dot given "n" dots in a ??? of Delta-PSI'

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