Infographic: npm badges

Mar 18, 2018. | By: Bogdan


More details about the research here.

[Read More]

Papers accepted at ICSE, MSR, ICGSE, and ICPC 2018

Mar 18, 2018. | By: Bogdan

Gothenburg, here we come! We have a strong presence at ICSE 2018 and colocated events this year:

  • Asher and Shurui have a paper on badges in npm at ICSE:

Adding Sparkle to Social Coding: An Empirical Study of Repository Badges in the npm Ecosystem

More details about the research here.

  • Alan and Jeremy have a paper on decompilation at ICPC:

Meaningful Variable Names for Decompiled Code: A Machine Translation Approach

  • Asher has a paper on code understandability at MSR:

“Automatically Assessing Code Understandability” Reanalyzed: Combined Metrics Matter

  • David has a paper on CI abandonment at MSR:

I’m Leaving You, Travis: A Continuous Integration Breakup Story

  • Pengcheng, Bowen, and Edgar (Graham’s students) have a paper on mining aligned pairs of code and natural language from Stack Overflow at MSR, and a poster at ICSE:

Learning to Mine Aligned Code and Natural Language Pairs from Stack Overflow

  • Fabio has a paper on mining personality traits for Apache contributors at ICGSE:

On Developers’ Personality in Large-scale Distributed Projects: The Case of the Apache Ecosystem

  • Miguel and Weslley (TU Eindhoven) have a paper on the role of localized Q&A sites, looking at Stack Overflow in Portuguese:

Is Stack Overflow in Portuguese attractive for Brazilian Users?

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Life @ CMU

Mar 18, 2018. | By: Sophie

Since I came to the Open House in March 2017, I found that CMU is a nerdy but cool space. I’m writing down things I find interesting here. Hope this blog can tell you more about CMU.

Mar 19, 2018.

In case of fire, do you use elevator.

Mar 18, 2018.

His heart is at work.

While most people were away last week because of the spring break, this guy sat at the teaching common the entire week. Apparantly, his heart is at work. A typical CMU student.

Mar 14, 2018.

Physicist Stephen Hawking died at the age of 76 on Pie Day

When the east coast was entering pie day, I heard that we lost Professor Stephen Hawking. Pie day is special not only because it is 3.14. It is also Einstein’s birthday. This year, it has also become Hawking’s death date. I still remember, when Professor Hawking’s books were translated into Chinese, TV programs were repeating over and over again that Profssor Hawking was born on the day on which Galileo Galilei died. Maybe great minds are always connected.

Speaking of Professor Hawking’s science, I thought of a comic sticked outside the office of Professor Thomas Ferguson, who helped construct Large Hadron Collider (LHC), in Wean Hall.

Mar 2, 2018.

Harry Potter Shabbat

I was surprised by how often I could spot a Harry Potter related thing on CMU campus. I was even more surprised when I found out that there would be a Harry Potter themed shabbat at Hillel Jewish University Center.

When I arrived at the front desk, there was a “sorting hat” from which you can draw an image of a house’s badge. This “sorting ceremony” decides which table you will sit at. I was “sorted” into Ravenclaw, although I was wearing Gryffindor gears. All three other houses’ tables are quickly filled, except for ours. By the time dinner started, we only had 3 people. The organizer said, “Maybe Ravenclaws are still studying.” That sounds like what CMU students are doing all the time. No wonder most students in our Harry Potter course identify them with Ravenclaw.

I can never forget how delicious their bread was!

And here’s a trivia:

Name a jewish student at Hogwarts.

Feb 14, 2018.

Valentine’s Day @ CMU

My office mate told us if you brought your laptop to the bookstore, they would clean it for free.

People celebrate Valentine’s Day with their valentines. Same here at CMU. However, CMU might have defined valentine slightly differently. It expanded the concept beyond human beings. Apart from your collaborators, people usually interact the most with their valentines. If we count objects as well, one’s laptop is definitely the number 1 valentine of most CMU students.

Feb 9, 2018.

Why are there rice noodles on the roof of Newell Simon Hall

You konw spring is coming when the snow on Newell Simon Hall’s rooftop becomes rice noodle (image on the right).

Image source of the second photos

Sep 28, 2017

Computer Science at CMU is not just for boys

You can find interesting things in restrooms! Here’s what I found in girls’ restroom on 5th floor in Gates:

Although it sounds great, I think they should have put it in boys’ restroom or on a public wall. I believe the intention was to encourage women to pursue computer science if that’s what they have been wanted to do. But the point I wanted to make is that women, maybe especially female graduate students, here at CMU are already brave enough to make it this far. We should not only focus on encouraging women, but also educate our male colleagues and build a friendly environment where woment don’t have to be encouraged to pursue their favourite subject. If CMU CS is gender inclusive, women can feel it. We don’t need to be reminded by a sign in a single restroom. If gender inclusiveness is something that CMU CS is proud of, then I wish to see this sign in a public space.

Sep 21, 2017

How to pull an all-nighter in 5 minutes?

Hey, have you pulled an all-nighter? NO?? You were too busy sleeping and forgot to stay awake all night pretending to work hard? Well, when you walk into the classroom, everyone will look like a panda except for you. You will look like an outsider!

Don’t worry. We’ve got you covered. If you go to the girls’ restroom on the 4th floor in Gates, you will see everything you need. Free of charge.

Sep 19, 2017

Happy smiley’s 35’s birthday!

Do you know who invented :-)? Where was :-) first used?

On 19 Sep, 1982, way before the emoji era, Scott Fahlman at CMU decided that people should use :-) for happy feeling and :-( for sad feeling. When they could only communicate through plain text, this was the cleverest idea. Now we have emoji, but I’d say text emoticons are still very useful and efficient. Here’s a list of text emoticons. (^o^)/ (◕‿◕✿)

BTW, do you know why CMU’s computer science ranks 1st? Because we invented bug swatter that can help our students quickly identify bugs so as to accelerate our research progress!

Sep 14, 2017

CMU is hiring!

Job description: clear the steep, overgrown hillside between the Gates Center and Purnell Center for the Arts.

Job compensation: tons of fress leaves!

Do you know who got the job? A group of goats!

For some unknown reasons, there was also a donkey.

Aug 16, 2017

First day in my new office! May the source code be with you!

[Read More]

STRUDEL Reading Group Updates

Feb 21, 2018. | By: Sophie

Wednesday, Feburary 21, 2018

Jeremy Lacomis presented the paper How to Design a Program Repair Bot? Insights from the Repairnator Project (Urli et al. ICSE 2018).

It is interesting to learn about online program repair bugs. When I was talking with a CMU undergrad at one of KGB’s activity, he was excited to learn that people are working on how to fix bugs automatically since he has some very unpleasant experience with debugging - so do many of us. It would be great if we could have a bug repairing bot with high accuracy in the future. However, as Marat pointed out, when the debugging process can be largely substituted by a robot, that means this language is dying. One example is Assembly. Here’s a quote from Paul Graham about the evolution of programming languages:

“What programmers in a hundred years will be looking for, most of all, is a language where you can throw together an unbelievably inefficient version 1 of a program with the least possible effort. At least, that’s how we’d describe it in present-day terms. What they’ll say is that they want a language that’s easy to program in.

Inefficient software isn’t gross. What’s gross is a language that makes programmers do needless work. Wasting programmer time is the true inefficiency, not wasting machine time. This will become ever more clear as computers get faster.” (source:

Wednesday, Feburary 14, 2018

Jason Yanwen Lin presented the paper Predicting Member Productivity and Withdrawal from Pre-Joining Attachments in Online Production Groups (Yu et al. CSCW 17).

This paper analysed withdrawl from Wikipedia groups using the attachment theories from social psychology. There results show that pre-joining connections are important to online production groups. Speaking from my personal experience, I totally agree with the authors. Especially in online community, when you often interact with people who you don’t konw much personal information, it can be hard to form attachment.

Wednesday, Feburary 7, 2018

Shurui Zhou presented the paper Almost There: A Study on Quasi-Contributors in Open-Source Software Projects (Steinmarcher et al., ICSE 2018).

It was interesting to learn that many people stopped making further contribution on GitHub after their first pull request was rejected. We also felt that there would be many future work worth pursuing. Thanks Shurui’s presentation as well as her snacks.

Since it was Alex’s meeting before he became a professor in Estonia, he also brought some pastries from Gates. We appreciated his intention of getting us fat. We will miss you.

By the way, I think Gates’ blueberry muffin is very nice, as well as banana & nuts in Scott. Nevertheless, no muffin compares to thos in Brown’s Blue Room or banana muffin at Corner Bakery Cafe.

Wednesday, Janurary 14, 2018

David Widder presented the paper Open Source barriers to entry, revisited: A tools perspective (Mendez et al. ICSE 2018).

Professor Margaret Burnett’s team has been studying GitHub’s gender inclusive issues. Since men and women are biologically different statistically, tools should be designed to cater their different ways of thinking and engaging with software. I do not think software developing is an inheritly male dominated task. I believe that getting more women into software developing is a key to gender equality. Yes, I am a feminist.

Davis is very good at baking, but I think he should have given out his delicious brownies at the beginning of his presentation rather than at the end.

Thusday, December 5, 2017

Sophie Qiu presented the paper The influence of visual feedback and gender dynamics on performance, perception and communication strategies in CSCW (Koulouri et al. International Journal of Human-Computer Studies 2017).

This paper shows that while men are statistically better at navigation with help from visual signals, women can use verbal communication to compensate such weakness and achieve the same level of excellency in navitation tasks. GenderMag, which David Widder will present later, is in the same mindset that although men and women are statistically biologically different, well-designed tools can help both of them succeed.

Sophie did not know that green been pie could contain cream so she bought a lot of them. Luckily, she could bring them to Strudel meetings so that everyone can eat them and be merry.

Tuesday, November 28, 2017

Bogdan Vasilescu presented the paper Code Coverage and Postrelease Defects: A Large-Scale Study on Open Source Projects (Kochhar et al. 2017).

This paper shows that code coverage in testing has insignificant correlation with the number of bugs at the project level of a software. Then my question was: how much test would be sufficient if a large software project could never be bug-free?

I do not remember what snack we had during that meeting.

Tuesday, November 21, 2017

Shurui Zhou presented the paper Some from here, some from there: cross-project code reuse in GitHub (Gharehyazie et al., MSR 2017).

This paper reminds me of two most popular ways of coding: Google-oriented coding and stackoverflow-oriented coding. It is expensive to write code from scratch, so understanding how code pieces are cloned across projects is useful.

I do not quite remember the snack but it might be Shurui’s Choco Pie.

Tuesday, November 14, 2017

Alexander Nolte presented the paper Flash Organizations: Crowdsourcing Complex Work by Structuring Crowds As Organizations.

It is a nice paper on how to more effectively form an software developing group. It was good to read some paper on HCI, which I was fascinated in but knew very little about.

Thanks for your cookies, Alex. I guess they came from La Prima Espresso in WEAN.

Tuesday, November 7, 2017

Alan Jaffe presented the paper Automatically Generating Commit Messages from Diffs Using Neural Machine Translation (Jiang et al., ASE 2017).

It is an interesting application of the naturalness of code. I learned a lot about the idea of naturalness of code, as well as the fact that Alan is very good at baking pumpkin pies.

Tuesday, October 31, 2017

No meeting this week. STRUDEL was away attending ASE in Urbana-Champaign, IL and visiting Fiona at the Cincinnati Zoo. #teamfiona

Tuesday, October 24, 2017

STRUDEL was proud to host Alexander Serebrenik from TU Eindhoven, who talked about his recent work on mining emotions from software engineering artifacts. We were all enjoying his talk as well as Sophie’s hazelnut wafel.

Tuesday, October 17, 2017

Sophie presented the paper Simultaneously Uncovering the Patterns of Brain Regions Involved in Different Story Reading Subprocesses (Wehbe et al., PLoS ONE 2014).

The researchers scanned participants brains while they were reading the ninth chapter of Harry Potter and the Sorcerer’s Stone. They then trained a classifier that can distinguish which short passage the participants were reading based on the neural activity. The choice of this paper was to present group members another machine learning classifier that can process fMRI results. It was very nice and sweet that David made apple raisin strudels.

Tuesday, October 10, 2017

Marat presented the paper Romantic partnerships and the dispersion of social ties: a network analysis of relationship status on facebook (Backstrom et al, CSCW 2014).

This paper proposed to use dispersion, which measures “the extent to which two people’s mutual friends are not themselves well-connected,” in addition to embeddedness, which measures the number of mutural friends, to predict if two Facebook users are in a romantic relationship. The accuracy of prediction increased significantly when using the dispersion metric. Somehow, my impression of the paper smells like homemade banana bread.

Tuesday, October 3, 2017

David presented the paper Automatically Diagnosing and Repairing Error Handling Bugs in C (Tian and Ray, ESEC/FSE 2017).

This paper presents how to identify different types of bugs and how to correct them in C/C++ code. Happy Mid-autumn festival and thanks Sophie for her mooncake!

Tuesday, September 26, 2017

Jeremy presented the paper Decoding the representation of code in the brain: An fMRI study of code review and expertise (Floyd et al, ICSE 2017).

The researchers scanned participants’ brain while they were reviewing code or prose. The findings suggest that reading code differs from reading natural language, but less so for experts than for novices.

Tuesday, September 19, 2017

We had our first reading group meeting today! To celebrate, Bogdan brought apple-cinnamon strudels for us. Nevertheless, these strudles were not as good as our discussion on the paper Fairness Testing: Testing Software for Discrimination (Galhotra et al, ESEC/FSE 2017) that Bogdan presented at the meeting.

[Read More]

Paper presented at ASE 2017

Oct 31, 2017. | By: Bogdan

We were at ASE 2017 presenting the paper:

The Impact of Continuous Integration on Other Software Development Practices: A Large-Scale Empirical Study, with Yangyang Zhao, Alexander Serebrenik, Yuming Zhou, and Vladimir Filkov.

More details about the research here. PDF here. Slides here.

[Read More]

Third place for Alan in the SRC!

Sep 8, 2017. | By: Bogdan

Congratulations to Alan who placed third in the ACM Student Research Competition at ESEC/FSE 2017 this year!

Check out his work on suggesting meaningful variable names for decompiled code.

More details about the research here.

[Read More]

Paper accepted at SWAN 2017

Jul 4, 2017. | By: Bogdan

We just had a paper accepted at SWAN 2017!

Timezone and Time-of-Day Variance in GitHub Teams: An Empirical Method and Study, with Prem Devanbu, Pallavi Kudigrama, and Cindy Rubio-González from UC Davis.

One of the coolest parts of the paper is the novel use of circular statistics. Did you know that traditional summary statistics (like the mean) are invalid for circular variables like the clock and angles? Here’s an example of circular histograms showing when people made commits in two GitHub projects. Check out the preprint for more details.


Open source projects based in ecosystems like GitHub seamlessly allow distributed software development. Contributors to some GitHub projects may originate from many different timezones; in others they may all reside in just one timezone. How might this timezone dispersion (or concentration) affect the diurnal distribution of work activity in these projects? In commercial projects, there has been a desire to use top-down management and work allocation to exploit timezone dispersion of project teams, to engender a more round-the-clock work cycle. We focus on GitHub, and explore the relationship between timezone dispersion and work activity dispersion. We find that while time-of-day work activity dispersion is indeed associated strongly with timezone dispersion, it is equally (if not more strongly) affected by project team size.

[Read More]

Paper accepted at ESEC/FSE 2017

Jun 2, 2017. | By: Bogdan

We just had a paper accepted at ESEC/FSE 2017!

Recovering Clear, Natural Identifiers from Obfuscated JavaScript Names, with Casey Casalnuovo and Prem Devanbu from UC Davis.

More details about the research here.

Try out our tool online.

[Read More]

STRUDEL is hosting 3 REU students

May 29, 2017. | By: Bogdan

We are thrilled to announce the arrival of 3 students participating in the Carnegie Mellon 2017 Research Experiences for Undergraduates in Software Engineering:

  • Anita Brown, from Bryn Mawr College
  • Asher Trockman, from University of Evansville
  • Jacob Hoffman, from Carnegie Mellon

Looking forward to a productive summer!

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Our new logo is here

May 19, 2017. | By: Bogdan

Thanks to Josh Quicksall’s amazing talents, the STRUDEL lab has a new logo! Can you spot where Josh got his inspiration from?

STRUDEL (Image from:

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Our Pastry Shop

Wean Hall 5115, Institute for Software Research
School of Computer Science, Carnegie Mellon University
5000 Forbes Ave
Pittsburgh, PA, 15213 USA