If you happen to work in the field of mining software repositories, this is a must-go. Interaction with other researchers in the field, and interesting discussions are guaranteed. Proceedings are probably the best collection to know about the state of the art in the field. Acceptance rates are relatively low.

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MSR is one of the fasted growing communities in software engineering. This year conference (MSR 2015 http://2015.msrconf.org) marks the 12th edition of MSR. MSR has grown from a workshop in 2004 to a conference since 2008. It has consistently been co-located with ICSE (A* ranked) since its inception. This year MSR received 136 submissions with an acceptance rate of 30%. Its current h5-index on Google Scholar is 25, higher than a number of A-ranked and B-ranked SE conferences such as ESEM (A, h5-index: 24), ISSRE (A, h5-index: 18), APSEC (B, h5-index: 15), and FASE (B, h5-index: 20). I personally think that MSR deserves a better rank than C.

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Echoing the previous comment, this year (2016) MSR received 133 submissions (103 full and 30 short research and practice paper submissions); out of the 103 full paper submissions, 36 papers were accepted, and out of the 30 short paper submissions, 6 papers were accepted. These are acceptance rates of 27% for full papers and 20% for short papers.

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People who work in mining software repositories would be surprised and shocked to see MSR is ranked 'C' !!! This should be an A ranked conference.

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MSR is the best conference in the area of "big data" approaches to questions/problems in software engineering, which is becoming a dominant part of the field. I find it indispensable to attend and/or read the papers. If you look at the google scholar rankings https://scholar.google.com/citations?view_op=top_venues&hl=en&vq=eng_softwaresystems it's clear that this is one of the top conferences in software engineering.

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This is the premier conference for utilizing mined data for software engineering research. It's a welcoming & vibrant community that is open to sharing & supporting new ideas. It should be rated as such -- the community & impact has grown significantly since it was originally rated.

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MSR has grown rapidly from a workshop to a conference. The ideas being presented are typically fresh and interesting, even though MSR is selective in what is published (acceptance rate < 30%). The community is very active, in that not only full papers are discussed, but also visions are. An important aspect of MSR is the mining challenge, in which people use their tools to study a common artefact. The impact of some of MSR's contributions is very important, also for the software engineering research community at large. I am surprised to see that its CORE ranking is C, as I would see MSR above some of the higher-ranked conferences in terms of both quality and importance in the larger community.

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MSR is THE conference for data-driven approaches to software engineering. The work published there is high quality, thoroughly evaluated and impactful. The MSR community has helped spearhead many technical innovations while it still remains a welcoming place for new students. It is surprising that the CORE ranking for MSR is only C. Other sources, such as the Google Scholar rankings, classify MSR among the top 5 conferences in the area of software engineering, programming languages and software systems.

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According to Google Scholar (https://scholar.google.ca/citations?view_op=top_venues&hl=en&vq=eng_softwaresystems), MSR has the 8th highest h5 index of all conferences and journals on software systems, outpacing giants like OOPSLA, the EMSE journal, ASE (!) and ICSME. In only 14 (!) editions, MSR techniques and technology have become a staple of any software engineering researcher's toolbox, which is not only due to the rigorous (but fair!) reviewing process of the MSR conference, but also (and especially) by the richness and openness of the MSR community. In fact, MSR has not only impacted researchers, but has helped large companies such as Google and Microsoft, and a variety of open source projects such as Eclipse, Mozilla or Debian, to noticeably improve their development and quality assurance processes. As such, the C score awarded by CORE clearly is an understatement.

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As others have mentioned, MSR is a very competitive and highly ranked conference in the field of Software Engineering. In a decade, MSR techniques have grown to be an essential component of Software Engineering research and is used in a large proportion of SE papers nowadays. MSR is the leading venue to discuss these approaches, as is ISSTA to software testing, or ICSME to software evolution. As the leading conference of an entire sub-field of Software Engineering, it should be ranked A, as these conferences are.

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