Tag Archives: data science

Data Story: Mohammad Shahangian on Pinterest Data Science

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At Gnip, we believe the value of social data is unlimited. Data Stories is how we bring this belief to life by showcasing how social data is used. This week we’re interviewing data scientist Mohammad Shahangian of Pinterest about how the data science team works at Pinterest, surprising uses of Pinterest and data science as a career path. You can follow him on Pinterest at pinterest.com/mshahang. 

Data Scientist at Pinterest

1. What do you see is your role as the data scientist for Pinterest?

The company’s focus is on helping millions of people discover things they love and get inspiration to go do those things in their life. For me, that means analyzing the rich data that is created by the millions of people interacting with billions of pins from across the web each day. I evaluate this data and provide insights that make data actionable. My team also prototypes and validates ideas, performs deep analysis and builds tools that allow us to answer our most frequent questions in seconds. We work with every team to answer Pinterest’s biggest questions and ensure that each decision positively impacts Pinners over the long term.

For example, we take a business question like “How should our web, tablet and phone experiences differ?” and present the results as insights like, “Many users use the mobile apps in the morning and again at night, but prefer the website during the day” and “Users prefer to use mobile apps to casually discover new content, whereas they use the web to curate and organize content.” We then work with the design and product teams to build features around these insights and measure their impact.

2. What are some of your favorite ways that people use Pinterest that people wouldn’t expect?

What makes Pinterest unique is that it’s a tool and the users really define its use cases. For me, Pinterest was really helpful when I was planning my wedding and it made perfect sense to use as collaborative office shopping list. I would have never thought to use it as a tool for:

A collection of Stop signs from around the world
Daily Grommet gets their community to collaborate on a board to see things they want to sell
Vintage Driving - a collaborative board where users pin their favorite vintage cars:
GE Badass machines featuring GE tech
Madewell’s Rainbow board
Michelle Obama’s MyPlate Recipes encourages health eating
Stunning virtual collections of minerals and shipwrecks
The “365 Days of Pinterest” challenge. She made a Pinterest project every day for a year!
Sammy Sosa awesomeness
Sony shows off their technology with food pictures shot with a Sony Camera
Pantone announces the color of the year
The National Pork Board

3. What category do you see as the most viral on Pinterest?

DIY and recipes pins generally go viral year round. Around the holidays, holiday-themed content across all categories tends to get the most traction.

4. How has data science added value to Pinterest?

We have this internal value we refer to as “knit.” It means that we have an open, curious culture where everyone in different disciplines—from engineering and design to marketing to community—works together. Data science is at the core of that. The search, recommendations and spam teams apply data science to improve the quality of content we put in front of Pinners. This is only a subset of how we apply data though; most of the decisions we make at Pinterest are actually backed by data.

Data is a universal language that teams across the company use to collaborate and make decisions. Each team has a set of performance metrics, and we hold a weekly meeting to understand the impact that each area is having on company-wide metrics. As data scientists we do more than just analyze data, we create rich data sources that we make available to other teams so they can do their own analysis. More than half of Pinterest employees run MapReduce jobs via Hive.  Our metrics dashboards are accessible to everyone and our core metrics are emailed daily to the entire team.  We also share our data studies and insights with the whole team.

We also use data just for fun. During our weekly happy hour, we share a weekly Data Fun Fact with the team. We present the fact in the form of a multiple choice question and have the team vote on the answer. For example, we asked, “How many days before Valentine’s day does the query ‘Valentine’s day ideas’ increase the most: 1, 3, 5 or 7 days?” (Hint for the curious reader: two*three/two).

5. What do you think someone should know before becoming a data scientist at a major web company like Pinterest?

I would say go for it! If you are hungry to extract value from real world data, you’re really going to enjoy it. I know that for a lot of really talented people in academia the only thing standing between them and the opportunity to solve a really interesting problem is the lack of rich data. My experience at Pinterest has been the exact opposite. Our team can’t grow fast enough to tap into a world of valuable insights that are sitting dormant within billions of records somewhere in the cloud.

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Data Stories: Dmitrii Vlasov on Kaggle Contests

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At Gnip, we’re big fans of what the team at Kaggle is doing and have a fun time keeping tabs on their contests. One contest that I loved was held by WordPress and GigaOm to see what posts were most likely to generate likes, and we interviewed Dmitrii Vlasov who came in second in the Splunk Innovation Prospect and sixth overall. For me, it was interesting to speak to an up and coming data scientist who isn’t well known yet. Follow him at @yablokoff.

Dmitrii Vlasov of the GigaOm WordPress contest

1. You were recognized for your work in the first Kaggle contest you ever entered. What attracted you to Kaggle, and specifically the WordPress competition?

I came to Kaggle accidentally as it always happens. I read some blog post about the Million Song Dataset Challenge provided by Last.fm and bunch of other organizations. The task was to predict which songs will be liked by users based on their existing listening history. This immediately made me feel excited because I’m an active Last.fm user and was reflecting about what connections between people can be established based on their music preferences. But the contest was coming to end and so I switched to WordPress GigaOm contest and got 6th place there. Well, it is always interesting to predict something you already use.

2. What is your background in data science?

Now I’m a senior CS student in Togliatty, Russia. Can’t say that I have a special background in Data Science – I had more than a year-long course of probability theory and math statistics in university, some self-learned skills about semantic analysis and have big love to Python as a tool for implementing ideas. Also, I’ve entered the Machine Learning course on Coursera.

3. You found that blog posts with 30 to 50 pictures were more likely to be popular. You also found that longer blog posts also attract more likes (80,000-90,000 characters). This struck my marketing team as really high and was contrary to your hypothesis that longer content might be less viral. Why do you think this is?

Well, my numbers show relative correlation between amount of photos, characters and videos and the amount of likes received. Big relative “folks love” on several prominent amount of photos means that there were not so many posts with such amount of photos but most of them were qualitative. Quick empirical analysis shows that these are special type of posts – “big photo posts”. They usually are photo report, photo collection or scrapbook. For such types of posts 10-15 photos are not enough but at the same time 10-15 photos seem too overloaded for normal post. The same can be said about big amount of text in post. Of course, the most “likeable” posts contain 1,000-3,000 characters, but posts with 80-90 thousands are winners in “heavyweight category”. These are big researches, novels, political contemplation. Analyse is quite simple but it shows that if you want to create media-rich or text-rich content it should be really media-text-rich. Or you may fall in a hollow of not suitableness.

4. What else would like to predict with social data if you got the chance?

Now I work on romantic and friend relationships that could be established based on people’s music preferences (it’s a privately held startup in alpha). This is a really interesting and deep area! Also, I’d like to work with some political data e.g. to predict reaction on one or another politician’s statement based on a user’s Twitter feed. Or to extract all “real” thesis of politician based on all of his public speeches.

Data Stories: Dino Citraro of Periscopic on Data Visualization

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The Periscopic team has a long-standing reputation for their excellent work in data visualizations, so we asked on of the founders, Dino Citraro, to participate in a Data Story about data visualizations. You can follow Dino on Twitter at @dinocitraro and check out their work at Periscopic.com. 

Dino Citraro of Periscopic

1) Periscopic’s tagline is “Do good with data”. What are some of the projects that Periscopic that embody that tagline?

We formed Periscopic with the hope that we could do good with data. To us that means helping people that share the ideals of progressive social change, sustainability, human rights, equality, environmentalism, and transparency to name a few. Most of our work enables insights and discussions in those areas. Some recent and/or notable projects are:

“VoteEasy”

VoteEasy.org is a voter education tool that was designed to allow the general public to quickly and easily see how closely political candidates align with their views on key issues. It’s like Match.com for political candidates. It utilizes thousands of hours of research and a vast collection of data assembled by the nonpartisan group, Project Vote Smart. It is the most up-to-date resource for candidate political information, including voting records, interest groups ratings, campaign finances, and personal biography.

http://www.periscopic.com/#/work/voteeasy

“The State of the Polar Bear”

The State of the Polar Bear is the authoritative source for the health and status of the world’s polar bears. This multipart datavisualization was developed through an international partnership with the Polar Bear Specialist Group, a scientific collaboration of the five polar bear nations: Canada, Denmark, Norway, the USA, and Russia. It covers data related to pollution levels, tribal hunting, and population dynamics of the bears.

http://www.periscopic.com/#/work/pbsg

“Who’s Talking About Breast Cancer”

Developed for GE’s Healthymagination data visualization forum, this tool takes a realtime look at the discussions happening on Twitter around the topic of breast cancer. Tweets from all over the world are aggregated in a single location, allowing visitors to quickly understand the current topics, trends, and stories.

http://www.periscopic.com/#/work/ge-breast-cancer

2) With infographics now being an over-hyped tool for marketing, what challenges does that create for a company actually trying to tell stories with data?

If they are done well, infographics can be a very effective story-telling device. Unfortunately, many of them seem to either lack an engaging metaphor, or don’t do a good job of letting the data be the story.  Since most of our work is interactive, we have an advantage over traditional infographics because we can reveal information in a user-directed way. The challenges we face are how to slowly introduce these stories in a way that is engaging for visitors, and not overwhelming.

3) What are the greatest opportunities right now for data visualization?

The greatest opportunities for data visualization probably relate to public data and personal data. Public data, because it has that greatest potential for good and efficiency. Personal data, because it is the thing that most people seem to find interesting. The Quantified Self movement has exploded, and along with it the desire to understand our social media behaviors, and the rise of the Quantified Social Self.

4) How do you separate the wheat from the chaff when it comes to good data? 

There is no such thing as “good data”, there is only good context. You can create a compelling data visualization out of any data source, as long as you use the right context.  For instance, one of our pieces uses the gaps in the data – the lack of data – as part of the story. Our client wanted to highlight the fact that they needed to increase the data collection efforts, and wanted public support for this effort. You could have a massive data set that is impeccably organized, but without the right context, it can go unnoticed.

5) How does good visualization help create data literacy?

To us, the issue is literacy in general. Like good design, data visualizations should be transparent and unnoticed. The epiphanies one gets from interacting with data are the things that should be retained, not the fact that an interface was unique, or the interactivity was sophisticated.

Having said that, the very process of interacting with data through a visualization tool brings an understanding of what is possible, and with that, the desire increases for more, and better experiences.

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In The Future, The Data Scientist Will be Replaced by Tools

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Some of you are celebrating. Some of you are muttering about how you could never be replaced by a machine.

What is the case for? What is the case against? How should we think about the investments in infrastructure, talent, education and tools that we hope will provide the competitive insights from “big data” everyone seems to be buzzing about?

First, you might ask why try to replace the data scientist with tools?  At least one reason is in the news: The looming talent gap.

WireUK reports,

Demand is already outstripping supply. A recent global survey from EMC found that 65 percent of data science professionals believe demand for data science talent will outpace supply over the next five years, while a report from last year by McKinsey identified the need in the US alone for at least 190,000 deep analytical data scientists in the coming years.”

Maybe we should turn to tools to replace some or all of what the data scientist does. Can you replace a data scientist with tools?  An emerging group of startups would like you to think this is already possible. For example, Metamarkets headlines their product page with “Data science as a service.” They go on to explain:

 Analyzing and understanding these data streams can increase revenue and improve user engagement, but only if you have the highly skilled data scientists necessary to turn data into useful information.

Metamarkets’ mission is to democratize data science by delivering powerful analytics that are easy and intuitive for everyone.

SriSatish Ambati of the early startup 0xdata (pronounced hex-data) goes a step further with the idea that “the scale of the underlying data and the complexity of running advanced analysis are details that need to be hidden.“ (GigaOm article)

On the other side of the coin, Cathy O’Neil at Mathbabe set out the case in her blog a few weeks ago that not only can you not replace the data scientist with tools, you shouldn’t even allow the non-data-scientist near the data scientist’s tools:

 As I see it, there are three problems with the democratization of algorithms:

 1. As described already, it lets people who can load data and press a button describe themselves as data scientists.

 2. It tempts companies to never hire anyone who actually knows how these things work, because they don’t see the point. This is a mistake, and could have dire consequences, both for the company and for the world, depending on how widely their crappy models get used.

 3. Businesses might think they have awesome data scientists when they don’t. [...] posers can be fantastically successful exactly because non-data scientists who hire data scientists in business, i.e. business people, don’t know how to test for real understanding.

If this is a topic that interests you, we’ve submitted a panel on this topic for SXSW this spring in Austin to discuss issues surrounding data science and tools. We will talk about what tools are available today, how they make us more effective as well as some of the pitfalls of tool use. And we will look into the future of tools to see where and if data scientists can be replaced by tools. Would love a vote!

Panelists:

  • John Myles White (@johnmyleswhite) – Coauthor of Machine learning for hackers and Ph.D. student in the Princeton Psychology Department, where he studies human decision-making.
  • Yael Garten (@yaelgarten) – Senior Data Scientist at LinkedIn.
  • James Dixon (@jamespentaho) – CTO at Pentaho, open source tools for business intelligence.

Update: One of our panelists, John Myles White, has provided some thoughtful analysis of companies that rely on automating or assisting data science tasks. See his blog post at http://www.johnmyleswhite.com/notebook/2012/08/28/will-data-scientists-be-replaced-by-tools

Twitter Shouts: Huntsman's Out!

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At Gnip, one of the most fascinating aspects of social media is ‘speed’ – specifically in regards to news stories. We continue to see a trend towards the ‘breaking’ of news stories on platforms like Twitter. Both the speed at which a story is broken as well as the speed at which that story catches on show the incredible power of this medium for information exchange. And as we’ve pointed out before, different social media streams offer different analytical value – Twitter versus a news feed for example.

Last night proved a great example of this as word of  Jon Huntsman’s withdrawal from the GOP presidential race crept out. Interestingly, the news was broken by Peter Hamby, a CNN Political Reporter–on Twitter. While CNN followed up on this news a few minutes later, it seems the reporter (or the network) realized the inherent ‘newswire’ value of breaking this news as fast as possible…and used Twitter as part of their strategy to do so!

This Tweet was followed with what we’ve begun to see as the normal ‘Twitter’ spike for breaking news – the chart below, built by our Data Scientist Scott, shows how quickly Huntsman withdrawl was retweeted and passed along. When looked at in comparison to an aggregate news feed (in this case, NewsGator’s Datawire Firehose, which is a content aggregator derived from crowdsourced rss feeds and contains many articles from traditional media providers), some interesting comparisons are brought to light.
Comparing the pulse of Twitter and NewsGator articles breaking Huntsman's withdrawal from the GOP primary race.
Comparing tweets of “huntsman” and news articles breaking Jon Huntsman’s withdrawal from GOP primary race. The blue curves show the “Social Activity Pulse” that characterizes the growth and decay of media activity around this topic. By fitting the rate of articles or tweets to a function we can compare standard measure such as time-to-peak, store half-life etc. (More on this in a future post.) The peak in Twitter is reached about the same time as the first story arrives from NewsGator, over 10 minutes after the story broke on Twitter.

Both streams show a similar curve in story adoption, peak and tail. What’s different is the timeframe of the content. Twitter’s data spikes about 10 minutes earlier than NewsGator’s. NewsGator’s content is more in-depth, as it contains news stories and blog posts, but as we’ve seen in other cases, Twitter is the place where news breaks these days.

 

Are Facebook Users More Optimistic than Twitter Users?

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New Year’s Eve gives us a sense of closure on the past and an opportunity to make new dreams. With the emergence of social media, we can now see these reflections and resolutions transpire in realtime. As we observed the posts, comments, and tweets related to the New Year, we saw the typical expressions on Facebook and Twitter of best wishes for the coming year and pithy observations about the past year. What we didn’t expect was that users of the two popular social media sites would have different outlooks on the world.

As we enter 2012, Facebook users are more optimistic than Twitter users.

You’re probably wondering how we can say that. Well, we looked at all of the public posts on Facebook and Tweets on Twitter that contained “Happy New Year.” For all of those posts and Tweets, we compared the use of positive words such as “better” and “good” to the use of negative words such as “worse” and “bad.” We found that Tweets with positive words appeared 8 times more frequently than Tweets with negative words. You might be thinking a ratio of 8 to 1 is pretty optimistic…

It may be, but posts on Facebook had a ratio of 40 to 1–such a huge difference lead us to speculate that Facebook is a more optimistic place than Twitter.

Interesting stuff. Could be a variety of reasons for the difference, from the mix of users on each service to the fact that Facebook is used to communicate with friends, while Twitter is user to broadcast to followers. We’ll leave the speculation up to you.

Gnip Cagefight #2: Pumpkin Pie vs. Pecan Pie

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Thanksgiving is a time for family gatherings, turkey with all the delicious fixings, football, and let’s not forget, pie! If your family is anything like mine, multiple pie flavors are required to satisfy the differing palates and strong opinions. So we wondered, which pies are people discussing for the holiday? What better way to celebrate and answer that question than with a Gnip Cagefight.

Welcome to the Battle of the Pies!

For those of you that have been in a pie eating contest or had a pie in the face, you know this one will be a fight all the way down to the very last crumb. In one corner (well actually it is the Gnip Octagon so can you really have corners, oh well) we have The Traditionalist, pumpkin pie and in the opposite corner, The New Comer, pecan pie. Without further ado, Ladies and Gentleman, Let’s Get Ready to Rumble, wait wrong sport. Let’s Fight!

Six Social Media Sources, Two Words, One Winner . . . And the Winner Is . . .

 

 Source  Pumpkin Pie  Pecan Pie  Winning Ratio
Pumpkin Pie to Pecan Pie
Twitter X 4:1
Facebook X 5:1
Google+ X 6:1
Newsgator X 3:1
WordPress X 5:1
WordPress Comments X 2:1
Overall +6 Winner! +0 :(

 

We looked at one week’s worth of data across six of the top social media sources and determined that pumpkin pie “takes the cake” (so to speak) across every source.

In this case, it is interesting to point out that in sources like Twitter, Facebook, Google+ and WordPress we see higher winning ratios, while sources that tend to have higher latency such as Newsgator and WordPress Comments were a little more even. Is this because, on further consideration, pecan pie sounds pretty good? Or is it that everyone will have to have two pies and, with pecan as the traditional second, it is highly discussed?

Top Pie Recipes

Even though pumpkin pie was our clear winner, we thought it would be fun to share a few of the most popular holiday pie recipes by social media source:

  1. Twitter – Cook du Jour Gluten-Free Pumpkin Pie and Pecan Pie Video Recipe from joyofcooking.com
  2. Facebook – Ben Starr’s Pumpkin Bourbon Pecan Pie Recipe
  3. Newsgator – BlogHer’s Pumpkin Pecan Roulade with Orange Mascarpone Cream Pie Recipe
  4. WordPress and WordPress Comments – Chocolate Bourbon Pecan Pie from allrecipes.com

Non-Traditional Thanksgiving Pies

Another interesting fact that came out of this Cagefight was the counts of non-traditional Thanksgiving pies that were mentioned across the social media sources we surveyed. Though we rarely find these useful for communicating numerical values effectively, you can’t not have a pie chart in this post.

Happy Thanksgiving!

Gnip Cagefight #1: Beer vs. Wine

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Welcome to the very first edition of the Gnip Cagefight! Over the next couple of weeks we’ll select a common word pair to enter the Gnip Octagon to fight to the finish in a no holds barred battle of Tweets. Two words will enter. Only one will leave.

In addition to crowning the victor, we’ll also call out some of the fun, interesting, strange, and bizarre trends that we glean from the data. Leave us a comment with any contenders you’d like to see in the future.

Now without further delay, let’s dive into our first Gnip Cagefight… Put your hands together for Wine vs. Beer!

And the Winner is . . .

We looked at one week of Tweets that contained the words “beer” or “wine,” and beer was the more commonly used term, appearing in 53.1% of those tweets vs. 48.1% for wine. Now you might be saying, “Hey, that’s more than 100%!” You are correct! That’s because beer and wine appear together about 13,801 times–along with an uncomfortable hangover, we presume. (Is this an opportunity to sell aspirin?)

With beer as our victor, we wanted to answer the age old question . . .

What time is Beer Thirty?

To answer this question, we analyzed the volume of Tweets containing the term “beer” throughout each day and averaged that across the week’s worth of data we collected. Each Tweet’s time was moved into the time zone of the Tweeter and normalized against the daily cycle of Tweet volume. Based on the graph below, true beer thirty is 5pm local time. This gives great meaning to the saying “It’s 5 o’clock somewhere.”

Beer Drinkers have a Wider Vocabulary than Wine Drinkers

Another fascinating tidbit that came out of the data was that beer drinkers have a wider vocabulary than wine drinkers. Normalizing for the number of words used, we find that beer drinkers use 14% more distinct words than wine drinkers. Wine drinkers tend to use the same idioms, for example, “glass of wine” or “red wine,” more than beer drinkers use their most common phrases. Does this mean that beer drinkers are 14% smarter than wine drinkers? Or that they use very creative spelling? We won’t wade any further into that question, but you can be the judge.

That’s all for our inaugural Gnip Cagefight. Hope you enjoyed it and be sure to let us know what what words you’d like to see in the octagon in the future.

The VMAs, Lady Gaga and Data Science

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Hi everyone. I’m the new Data Scientist here at Gnip. I’ll be analyzing the fascinating data that we have coming from all of our varied social data streams to pull out the stories, both impactful and trivial, that are flowing through social media conversations. I’m still getting up-to-speed but wanted to share one of the first social events that I’ve dug into, the 2011 MTV Video Music Awards.

Check out the info below and let me know in the comments what you think and what you’d like to see more of.  And now, on with the show…

3.6M Tweets Mention “VMA”

The volume of tweets containing “VMA” rose steadily from a few hours before the VMA pre-show was broadcast, up to the starting of the pre-show at 8:00 PM ET (00:00 GMT) and remained fairly strong during the event. It trailed to low volume within the hour after the VMA broadcast ended at 11:15 PM ET (03:15 GMT). Tweets mentioning “VMA” totaled 3.6M during the 7 hours surrounding and including the VMA broadcast.

 

Lady Gaga Steals the “Tweet” Show

The largest volume of tweets for an individual artist are the mentions of “gaga.” Lady Gaga performed early in the show and the surge of tweets during her performance surpassed 35k tweets per minute for about 8 minutes. Again in the second half, Lady Gaga tweet volume briefly jumped above 50k per minute. Tweets mentioning “gaga” totaled 1.8M during the 7 hours surrounding and including the VMA broadcast.

As you can see in the chart below, other artists that garnered significant tweet volumes included Beyonce’, Justin Beiber, Chris Brown, Katy Perry and Kanye West. Perry, West and Brown got a lot of attention during their appearances, while Justin Bieber and Lady Gaga lead the counts in volume by maintaining a fairly steady stream of tweets during the broadcast.

Term Representation of Tweets Sampled
VMA 44 %
Lady Gaga 21 %
Beyonce 16 %
Justin Bieber 10 %
MTV 9.2 %
Chris Brown 8.0 %
Katy Perry 5.6 %
Kanye West 4.8 %
Jonas 3.5 %
Taylor Swift 2.1 %
Rihanna 1.1 %
Eminem 0.55 %
Michael Jackson 0.18 %
Ke$ha 0.17 %
Cher 0.14 %
Paramore 0.12 %

 

 

 

Contrasting, it is interesting to note that Beyonce’ and Chris Brown gained most of their tweet attention around their performances with very larger surges in tweet volume. Beyonce’s volume–another Beyonce’ bump–continues after her performance as twitter users absorb the news of her pregnancy.

 

 

One surprise that emerges from looking for other artists connected to the VMAs was Michael Jackson’s tweet volume. While Jackson gleaned many Retweets after winning the King of the VMA poll, he also received a large number of natural tweets lamenting his passing and celebrating his past successes.

Methodology

The free-form text and limited length of twitter messages creates a number of challenges for monitoring an event via twitter comments. People refer to the event differently and focus on different parts of the event. There will be spelling variations and differences in idioms and nicknames used to describe people and performances. Do we search for “Bieber”,”Beiber” and “Justin”?  Will tweeters use “Beyonce” or Beyonce’”? Knowledge of what we are monitoring is required; preparing tools to adapt things we learn during the events is also essential to getting good results.

One effective strategy is to use one or two tokens to identify tweets related to the event. The objective is to choose terms that we know are related to the event, that won’t be widely used outside the event, and that will give a representative sample–diverse and with sufficient volume. Once we have started to collect the event-focused twitter sample, we can look for relevant terms correlated with the filter term to find out what else people are tweeting about during the event.

Hope you enjoyed this first post. Look for more to come.