We investigate some effects that the `light' trimming of a sum
Sn = X1 +
X2 + · · · +
Xn of independent and identically
distributed random variables has on behaviour of iterated
logarithm type. Light trimming is defined as removing a constant
number of summands from Sn. We consider
two versions: (r)Sn,
which is obtained by deleting the r largest
Xi from Sn, and
(r) S̃ n, which
is obtained by deleting the r variables
Xi which are largest in absolute value
from Sn. We summarise some relevant
results from Rogozin (1968), Heyde (1969), and later writers
concerning the untrimmed sum, and add some new results concerning
trimmed sums. Among other things we show that a general form of
the law of the iterated logarithm holds for (r)
S̃ n but not (completely) for
(r)Sn.
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