I'm writing a paper about an algorithm. The algorithm is qualitatively evaluated using empirical tests on sample data. I find it difficult to find a good word for multiple such data. It should be possible to put the word which describes this in plural form, describing multiple sets of multiple such data.
To be more precise:
My algorithm takes some input data (a "problem instance") and generates an output. Similar problem instances are grouped together, and for that I am looking for a word to describe this. And also, I need to be able to talk about multiple such groups: they have different properties, but within one such "group" the instances have similar properties.
For example (in which I call it "sets of instances"):
We generated the following "sets of instances". Primarily, we need different sizes of inputs, so one "set" contains small instances, the second one medium-sized instances, and the third one large instances.
Note: the input data is automatically generated randomly, and as such artificially created (i.e. not an extracted sample of real data).