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Ways Data Projects Fail

martingoodson.com

51–60 of 79 posts

Re: Ways Data Projects Fail

#51
A big fallacy seems to be that it is meaningful to just use existing data in whatever cruddy non-normalized form it comes in, and let the 'algorithms' sort it out.

There needs to be strong mgmt support for getting outcomes, because the production team are going to have to change to support it, and they usually like doing things their own way. Typically, without analytics, sensible logging formats or a clue as to why the outside world behaves the way it does.

Re: Ways Data Projects Fail

#52
This is related to point 7, solution in search of a problem. I myself have been guilty of this when I wanted to use deep learning models just because I could. My much more experienced boss gently dissuaded me and I ended up with a 'boring old' logistic regression, which was completely adequate for the job.

Another time I was working with an engineer who built a neural net to predict something. Turned out it was a really poor choice as interpretability was important for the problem and the neural net's predictive power was actually worse than more traditional models.

Re: Ways Data Projects Fail

#53

Good to see that data cleaning was #1 on that list. Whenever I do work on a side project, it takes way way more time to get and structure the data than it does running the algorithms. Granted, that's because I have to go out and get the data in the first place, and then make sure it's useable and in the correct format. Like the recent project I'm doing trying to classify country music songs based on their topic on th…

I don't get why companies would hire data scientists to do ETL jobs. These are properly left to engineers with expertise in data warehousing. From what I see though, this is a pretty common occurrence in Silicon Valley.

Re: Ways Data Projects Fail

#54

>Your Data Scientists are about to quit. This is me. I work for a non-profit that is stuck in the stone age--not for lack of money, mind you, but because the IT Director is an incompetent megalomaniac who views "security" as a reasonable justification to refuse any and all requests, and treats everyone like an enemy. I haven't been allowed to use Python or R. In fact, the only programming language I have access to is…

I am with you on everything but the complaint about

> my computer is a Core 2 Duo from 2007 or so with 4 gb of ram

That's a super freaking powerful machine, you have to be efficient in your programs and good on your algorithms. My machine was a Pentium III 800MB RAM for the longest time. There is a lot you can do on that. Use algorithms that need to load data in chunks, exploit memory mapping and generate native code if you can. They go a long way, likely much further than some may think.

Re: Ways Data Projects Fail

#55
post #38
post #31

Earlier quoted context omitted.

And it's much less useful cousin hiding in the shadows "The variables are actually predictive of X, but you don't have enough data that it shows". (The chance for which isn't that big when done "properly".)

At least in online contexts, this often means 'there might be an effect, but it is smaller than our experiment could have predicted. Let's keep adding samples.'

'... until we get the answer we're expecting'.

Just expecting an effect is a bias towards outliers.

http://doingbayesiandataanalysis.blogspot.com.au/2013/11/opt...

Re: Ways Data Projects Fail

#56

Good to see that data cleaning was #1 on that list. Whenever I do work on a side project, it takes way way more time to get and structure the data than it does running the algorithms. Granted, that's because I have to go out and get the data in the first place, and then make sure it's useable and in the correct format. Like the recent project I'm doing trying to classify country music songs based on their topic on th…

Agreed! However, data cleaning is a pretty hard problem. My previous company stored merchant credit card transactions, and these transactions were large unwieldy beasts whose data model had changed many times over the course of the company. Old data was completely invalid, and yet we couldn't remove it because the dollars and cents had to add up. The cleaning significantly hindered new development. Validations when storing new data definitely help, but changes to the data model are tough to reconcile with old data.

Re: Ways Data Projects Fail

#57
This is great advice. I'd add that the culture around data engineering projects tend to be very different.

I've seen companies that treat data projects as if they were this great unknown projects where the developers could get away with using bad or no patterns and not follow patterns that other applications in the company use.

Technologies like Spark have made more common and easier to develop big data applications and implement design patterns that regular engineers can understand and follow.

Couple a great data engineer that with great data scientist using tools like Spark, R, H2O, Alluxio, Parquet, etc. and companies can truly exploit their large sets of data effectively.

The problem is DevOps and bridging the gap between a scientist's environment and a production environment and keeping both as flexible and testable as possible.

We started a company to bootstrap companies into this culture by providing DevOps services and UIs which simplify the deployment of Kubernets, Spark, Druid, H2O, etc. clusters. We also provide tools and services for simplifying and automating ETL pipelines with which models can be trained.

If you are interested in finding out more about these services contact us at: miguel@zero-x.co.

Re: Ways Data Projects Fail

#58

Good to see that data cleaning was #1 on that list. Whenever I do work on a side project, it takes way way more time to get and structure the data than it does running the algorithms. Granted, that's because I have to go out and get the data in the first place, and then make sure it's useable and in the correct format. Like the recent project I'm doing trying to classify country music songs based on their topic on th…

Any specific resources you'd recommend on data cleaning, verification, etcetera? I've just started reading this: https://www.amazon.com/Accuracy-Economic-Observations-Oskar-... . I've seen a few other books on the subject which I'm planning to get into, but I'd be interested if anyone has specific recommendations.

Apache NiFi is pretty decent. Eg http://www.slideshare.net/BryanBende/building-data-pipelines...

Re: Ways Data Projects Fail

#59

Good to see that data cleaning was #1 on that list. Whenever I do work on a side project, it takes way way more time to get and structure the data than it does running the algorithms. Granted, that's because I have to go out and get the data in the first place, and then make sure it's useable and in the correct format. Like the recent project I'm doing trying to classify country music songs based on their topic on th…

Hundred times this. You see Qlik/Cognos Analytics/PowerBI/Alteryx/whatever sales guys making demos that make executives drool over the seeming easiness and wow-factor these tools are capable of producing. When the time comes to plug those over your production operative systems, CRM, whatelse, there comes "the now wait a minute" moment especially if your systems and their data models happen to be even slightly on the more complex side.

Edit: The basis of succesful implementation of these tools is to have the data in digestible format and I feel that transforming the data to that business usable format is where the big job is.

In my opinion well done ETL and DW are not going anywhere, even though in some circles they are said to be things of yesterday. Then there's a huge difference between an OK ETL/DW and a Brilliant ETL/DW. Designing a good ETL process is as large parts business and context knowledge as it is a application of data engineering skills. For example, it requires business knowledge AND data engineering knowledge to determine what kind of granular level advanced metrics could or should be calculated during ETL. Service level metrics and service level categorization for different kind of customers/claims/orders/... would be a perfect simple to understand example problem - there could be attributes and value ranges behind multiple relations that probably need to be taken into account and understood.

Edit 2: I've been involved in both sales and execution of so called data discovery sprints, which are a 4-6 week periods where we bring a data engineer, a subject matter expert and client key personnel working together and let them go "fishing". The key thing is that this provides an low cost way for the clients to possibly gain insight on the potential their data could provide. On the other hand, many prospective clients just have so messy data that this data discovery job can't be recommended, which leads to other possible opportunities (MDM, ETL, DW).

Re: Ways Data Projects Fail

#60
What I have seen in my limited practice with machine learning and big data projects is that it is easy to fool yourself that your methods work. And the problem is that the people who are good at this get promoted, and those who find the mistakes are shunned.
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