Abstract
Distribution testing can be described as follows: q samples are being drawn from some unknown distribution P over a known domain [n]. After the sampling process, a decision must be made about whether P holds some property, or is far from it. The most studied problem in the field is arguably uniformity testing, where one needs to distinguish the case that P is uniform over [n] from the case that P is εfar from being uniform (in 𝓁₁). It is known that for this task Θ(√n/ε²) samples are necessary and sufficient. This problem was recently considered in various restricted models that pose, for example, communication or memory constraints. In more than one occasion, the known optimal solution boils down to counting collisions among the drawn samples (each two samples that have the same value add one to the count). This idea dates back to the first uniformity tester, and was coined the name "collisionbased tester".
In this paper, we introduce the notion of comparison graphs and use it to formally define a generalized collisionbased tester. Roughly speaking, the edges of the graph indicate the tester which pairs of samples should be compared (that is, the original tester is induced by a clique, where all pairs are being compared). We prove a structural theorem that gives a sufficient condition for a comparison graph to induce a good uniformity tester. As an application, we develop a generic method to test uniformity, and devise nearlyoptimal uniformity testers under various computational constraints. We improve and simplify a few known results, and introduce a new constrained model in which the method also produces an efficient tester.
The idea behind our method is to translate computational constraints of a certain model to ones on the comparison graph, which paves the way to finding a good graph: a set of comparisons allowed by the model that suffice to test for uniformity. We believe that in future consideration of uniformity testing in new models, our method can be used to obtain efficient testers with minimal effort.
BibTeX  Entry
@InProceedings{meir:LIPIcs.ITCS.2021.17,
author = {Uri Meir},
title = {{Comparison Graphs: A Unified Method for Uniformity Testing}},
booktitle = {12th Innovations in Theoretical Computer Science Conference (ITCS 2021)},
pages = {17:117:20},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {9783959771771},
ISSN = {18688969},
year = {2021},
volume = {185},
editor = {James R. Lee},
publisher = {Schloss DagstuhlLeibnizZentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/opus/volltexte/2021/13556},
URN = {urn:nbn:de:0030drops135560},
doi = {10.4230/LIPIcs.ITCS.2021.17},
annote = {Keywords: Distribution Testing, Uniformity Testing, Distributed Algorithms, Streaming Algorithms, Comparison Graphs}
}
Keywords: 

Distribution Testing, Uniformity Testing, Distributed Algorithms, Streaming Algorithms, Comparison Graphs 
Collection: 

12th Innovations in Theoretical Computer Science Conference (ITCS 2021) 
Issue Date: 

2021 
Date of publication: 

04.02.2021 