Do researchers reuse benchmark results for existing algorithm when comparing with their algorithm? Unfortunately I do not have any prior research experience, therefore I had a few questions while I was studying papers on cluster analysis.

Can a researcher legally and with permission use the benchmark values of the pre-existing algorithm to compare with theirs? This question came to me after I noticed identical results reported in multiple papers for some population based cluster analysis algorithms. The different papers propose a new algorithm and then compare the performance of it with some other algorithms over some common dataset. I have noticed that, for some algorithms the values reported are an exact match. The nature of these algorithm is stochastic, and also the different authors claim to have run the algorithms different number of iterations and then use the mean. Therefore no two sets of run will result with the same mean, min, max and standard deviation.

My suspicion is either it is permissible to reuse the benchmark results with permission. Or a common benchmarking framework exists (still, how can two papers reporting using different number of iterations land into the same identical result?)

I have reproduced the work of the papers using Octave and benchmark is similar to what is reported in the papers, but is definitely not identical.

Also, how generally these are done? If a researcher has to implement 5 algorithms to compare, then do they implement their own and then verify and compare or request the version the author has used and then benchmark with respect to that specific piece of code to maintain unbiased experimentation?

[EDIT]

Quoting the results from another paper (with citation) is all right, but using it in the benchmark comparison table is something which is practiced in research?
Quoting the results from another paper (with citation) is all right, but using it in the benchmark comparison table is something which is practiced in research?


I would wager it is not done enough. It is certainly ok, even required, to compare your results to earlier work, and the more fair and unbiased you can do this, the better. It is perfectly acceptable to say "on the right-hand side of Table XY, we report the results for this problem previously achieved in [1]" (and then list them exactly as reported).

The one thing to make sure, though, is that when you want to say that you are better than a previous work, the comparison is actually fair. For instance, one sometimes sees papers where the authors use a long-running deterministic algorithm (which you need a map/reduce cluster to execute on) and claim that their work is better than an earlier heuristic approach, which was built for speed and on-line execution. Don't do that.