# Is “iterative cycle” a tautology?

If something is iterative, it means it repeats.
A cycle is also something that is repeated.

So is "iterative cycle" tautological — a redundant way of saying "iteration"?

For example:

We performed three iterations of the experiment.

vs

The experiment had three iterative cycles.

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A cycle implies that it comes back round to the starting point, and iteration does not. I don't believe the second statement to be redundant. – cornbread ninja 麵包忍者 Mar 29 '12 at 21:19
Think of a helix where iteration is progress along the main axis and cycles are revolutions about it. – Jon Purdy Jun 16 '12 at 22:23

From a developmental standpoint, iteratively implies that some progress is being made in each iteration. According to one dictionary, an iteration is a procedure in which repetition of a sequence of operations yields results successively closer to a desired result. A cycle, on the other hand, is a single complete execution of a periodically repeated phenomenon or event.

I might make a lasagne iteratively, by putting down a layer of noodles, and a layer of filling, with each iteration.

If each layer of lasagna has the same filling, put down in the same order (e.g., sauce-meat-cheese), then a 5-layer lasagne could be built in five iterative cycles.

However, if it was a 3-layer lasagne, and the middle layer was different from the other two, then the lasagne would be built iteratively, in three steps, but not cyclically.

Lastly, if it was a 9-layer lasagne, comprised of three "triple layers" as described above, then the lasagne could be completed in three cycles of three iterations each, for a total of 9 iterations.

These two words have secondary meanings, and need not be used strictly in the sense I've defined them above; however, the way I've used them illustrates that iterative cycle isn't necessarily redundant.

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Thanks for this; nice example. In terms of research work (or in my case, software development), I feel that "iterative cycles" is generally not what is meant — we are getting closer to a desired result with each iteration, but usually not by doing the same thing over and over again (cyclically); we improve our processes with each new iteration. But I see that "iterative cycle" can make sense. – Christopher Mar 29 '12 at 21:59
+1 for the Italian plural of lasagna, since they are made from more than one noodle. – Xantix Dec 30 '12 at 5:05

I would parse those two statements differently.

In the first, there was one experiment which was repeated three times.

In the second, there was one experiment, which had three parts, and each part was capable of being repeated an unknown number of times.

So, the way I read it, an 'iteration cycle' is basically a unit which can be iterated.

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I understand a cycle as a process composed of more than one part (e.g. spring->summer->autumn->winter... then back to spring). If there's only one kind of process being repeated (e.g. putting one layer after the other) this wouldn't be a cycle, except if there were different kinds of layers (e.g. lA->lB->lC->lA->lB>lC, and so on), maybe this last example could be considered a iterative cycle. The first example (seasons) is not iterative because one season substitutes the other, there's no build up from the repetition.

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Probably, you should replace "back to summer" with "back to spring". – user19148 Jun 16 '12 at 21:49
thanks, i corrected it now – Tames Jun 16 '12 at 22:07