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How to learn data science

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Re: How to learn data science

#51
post #3

Good article for beginners. A couple thoughts, just to build on what the author said: First off, data science == fancy name for data mining/analysis. Wanted to clear that up due to buzzwordy nature of "data science." Learn SQL - this is the big one. You must be proficient with SQL to be effective at data science. Whether it's running on an RDBMS or translating to map/reduce (Hive) or DAG (Spark), SQL is invaluable. I…

But how do you become a good data scientist, instead of a technical person, that knows how to apply an algorithm in Python/R.

What I am trying to ask is how do you become good at setting your start point(formulate your hypotheses), communicating your insights and selecting which tools apply where, because if your are good at coding and have experience in things related to computer science you have the abilities to handle a dataset(SQL Knowledge) and the data tools(Python, Pandas, etc), but that doesn't earn you the title of data scientist.

Re: How to learn data science

#52
post #26

Earlier quoted context omitted.

Roughly 80% of data scientists I know have PhD in something very math heavy. Rest have masters degrees. There are programmers who can assist them doing the grunt work but it's just basic programming to assist analysts to crunch data. If you want to do data science for real: 1. Get Masters of PhD from statistics, computer science, economics, physics or some other heavy field and specialize data analysis in that field.…

No. A phd in statistics or economics means almost nothing at this point. Even if it did, truly, signal mastery of the content, which it doesn't anymore, it would signal to most people who do this kind of work that you're way overqualified while simultaneously being totally ignorant of the day-to-day work of actual data scientists. If you want to be a useful data scientist, do a lot of work with data. If you have stro…

I've had complete opposite experience. Do the people who hire for this kind of work often bet on non-PhD candidates? Do they trust themselves to separate the wheat from the chaff?

Don't you want a colleague who is able to mention seminal papers for specific problems? Who is able to read and understand these papers and can distill useful features and optimizations from them?

People with PhD who go into business, usually end up in the better positions. They hire other PhD's for the good positions to keep the signal (mastery of the content) stronger.

As someone who did a lot of work with data I have little problem with my usefulness, but a lot of problems opening doors to the really interesting data companies (lacking a proper academic network). I wish I had gotten that PhD, because right now applying to Google, Microsoft, Facebook, Yahoo or eBay for data science positions makes me look like a fool.

Re: How to learn data science

#53
post #26

Earlier quoted context omitted.

Roughly 80% of data scientists I know have PhD in something very math heavy. Rest have masters degrees. There are programmers who can assist them doing the grunt work but it's just basic programming to assist analysts to crunch data. If you want to do data science for real: 1. Get Masters of PhD from statistics, computer science, economics, physics or some other heavy field and specialize data analysis in that field.…

No. A phd in statistics or economics means almost nothing at this point. Even if it did, truly, signal mastery of the content, which it doesn't anymore, it would signal to most people who do this kind of work that you're way overqualified while simultaneously being totally ignorant of the day-to-day work of actual data scientists. If you want to be a useful data scientist, do a lot of work with data. If you have stro…

>Spending the better part of your young adulthood getting a phd in statistics, unless you want to go into academia, just makes you look like a fool.

This is why you are a DataWorker, and not a dataScientist.

Anyone can push bits around. It takes a trained mind to corral them using careful experimentation and observation.

Re: How to learn data science

#54
post #31

Moving data around is just grunt work. Real science requires a creative and critical mind, which takes years to mold.

Sounds like you've also spent years molding professional disdain for everyone who's not a Real Scientist.

No I've just seen too many people spin their wheels on "analysis" that is not hypothesis driven.

You got to start with questions to get answers, and the hard part of science isn't crunching data, it is asking the right question!

Re: How to learn data science

#55

Anyone interested in data science should first study cognitive psychology. The CIA has a manual on the psychology of intelligence analysis that is a must read for anyone pursuing any analytical job. If you dont understand how your mind sees, processes, retains and recalls data...how can you possibly analyze it accurately?

You have a link to where to obtain said manual?

Re: How to learn data science

#56
post #26

Earlier quoted context omitted.

Roughly 80% of data scientists I know have PhD in something very math heavy. Rest have masters degrees. There are programmers who can assist them doing the grunt work but it's just basic programming to assist analysts to crunch data. If you want to do data science for real: 1. Get Masters of PhD from statistics, computer science, economics, physics or some other heavy field and specialize data analysis in that field.…

No. A phd in statistics or economics means almost nothing at this point. Even if it did, truly, signal mastery of the content, which it doesn't anymore, it would signal to most people who do this kind of work that you're way overqualified while simultaneously being totally ignorant of the day-to-day work of actual data scientists. If you want to be a useful data scientist, do a lot of work with data. If you have stro…

You've said "No", but you haven't countered the posters claims. Are in fact most data scientists PhD/Masters people? I hear the same information at a mid-sized tech company. I also hear similar things about Intel.

Re: How to learn data science

#57
post #51
post #3

Good article for beginners. A couple thoughts, just to build on what the author said: First off, data science == fancy name for data mining/analysis. Wanted to clear that up due to buzzwordy nature of "data science." Learn SQL - this is the big one. You must be proficient with SQL to be effective at data science. Whether it's running on an RDBMS or translating to map/reduce (Hive) or DAG (Spark), SQL is invaluable. I…

But how do you become a good data scientist, instead of a technical person, that knows how to apply an algorithm in Python/R. What I am trying to ask is how do you become good at setting your start point(formulate your hypotheses), communicating your insights and selecting which tools apply where, because if your are good at coding and have experience in things related to computer science you have the abilities to ha…

Practice. And education, but mostly practice. This is the kind of thing that is typically taught in formal educational settings (at least in engineering, which is my experience). As an example, I learned more about probability & statistics in 1) AP biology in high school, and 2) a "simulation systems" class in my industrial engineering master's curriculum. We spent much of the former class learning basic statistical analysis techniques (ANOVA, chi-square, etc) to apply to our lab data, and the latter class was all about statistical analysis of process flows (aimed at the real life problem of factory production planning & scheduling and manufacturing process optimization).

So, do I consider myself a data scientist? Absolutely not. But do I understand basic statistical concepts and know how to apply them to several categories of real life data analysis problems.

I'm a terrible coder, btw.

Re: How to learn data science

#58
post #52

Earlier quoted context omitted.

No. A phd in statistics or economics means almost nothing at this point. Even if it did, truly, signal mastery of the content, which it doesn't anymore, it would signal to most people who do this kind of work that you're way overqualified while simultaneously being totally ignorant of the day-to-day work of actual data scientists. If you want to be a useful data scientist, do a lot of work with data. If you have stro…

I've had complete opposite experience. Do the people who hire for this kind of work often bet on non-PhD candidates? Do they trust themselves to separate the wheat from the chaff? Don't you want a colleague who is able to mention seminal papers for specific problems? Who is able to read and understand these papers and can distill useful features and optimizations from them? People with PhD who go into business, usual…

I've met a lot of fools who've quoted all the right works, in both Computer Science and Data Science. Computer Science fools usually get fired. Data Science fools seem to get promoted to Yes-man status. It's a lot harder to lie about your code than it is with statistics; As the old adage goes, it right behind Lies and Damned Lies.

Re: How to learn data science

#59
Here are some topics. Are they considered relevant to data science?

Matrix row rank and column rank are equal.

In matrix theory, the polar decomposition.

Each Hermitian matrix has an orthogonal basis of eigenvectors.

Weak law of large numbers.

Strong law of large numbers.

The Radon-Nikodym theorem and conditional expectation.

Sample mean and variance are sufficient statistics for independent, identically distributed samples from a univariate Gaussian distribution.

The Neyman-Pearson lemma.

The Cramer-Rao lower bound.

The margingale convergence theorem.

Convergence results of Markov chains.

Markov processes in continuous time.

The law of the iterated logarithm.

The Lindeberg-Feller version of the central limit theorem.

The normal equations of linear regression analysis.

Non-parametric statistical hypothesis tests.

Power spectral estimation of second order, stationary stochastic processes.

Resampling plans.

Unbiased estimation.

Minimum variance estimation.

Maximum likelihood estimation.

Uniform minimum variance unbiased estimation.

Wiener filtering.

Kalman filtering.

Autoregressive moving average (ARMA) processes.

Rank statistics are always sufficient.

Farkas lemma.

Minimum spanning trees on directed graphs.

The simplex algorithm of linear programming.

Column generation in linear programming (Gilmore-Gomory).

The simplex algorithm for min cost capacitated network flows.

conjugate gradients.

The Kuhn-Tucker conditions.

Constraint qualifications for the Kuhn-Tucker conditions.

Fourier series.

The Fourier transform.

Hilbert space.

Banach space.

Quasi-Newton iteration and updates, e.g., Broyden-Fletcher-Goldfarb-Shanno.

Orthogonal polynomials for numerically stable polynomial curve fitting.

Lagrange multipliers.

The Pontryagin maximum principle.

Quadratic programming.

Convex programming.

Multi-objective programming.

Integer linear programming.

Deterministic dynamic programming.

Stochastic dynamic programming.

The linear-quadratic-Gaussian case of dynamic programming.

Re: How to learn data science

#60
post #37
post #3

Good article for beginners. A couple thoughts, just to build on what the author said: First off, data science == fancy name for data mining/analysis. Wanted to clear that up due to buzzwordy nature of "data science." Learn SQL - this is the big one. You must be proficient with SQL to be effective at data science. Whether it's running on an RDBMS or translating to map/reduce (Hive) or DAG (Spark), SQL is invaluable. I…

I would shift priorities to Python (from SQL). Unless one has "data scientist" title so to make "database engineer" look more fancy, then data comes in various shapes and forms. And most questions cannot be answered with a simple aggregation. For example, data I work on (I am a data scientist freelancer) is flat csv files, xls files, JSON files, some text files I need to parse, various SQL, MongoDB, things I am getti…

I would disagree with that advice. If you work as a data scientist in a company, you will likely have the logs of something stored in an SQL table (be it pure SQL database or something like hadoop hive) and you will have to answer (and ask) to questions like: "Do people convert more when they come from X or Y?", so you will have to do a couple of queries to get the conversion rates from people coming from X and Y.

This is my experience when I worked as Data Scientist about a year ago. Now, YMMV, especially if you're a freelancer, I guess your clients are more comfortable with giving you raw dumps of data as files instead of giving you access to their database servers.

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