Thoughts on PhD


This post serves as a record of thoughts regarding PhD. This post is from the person who is about to embark on the journey of getting a PhD. The thoughts from this post may look stupid or naive for someone who has already gone through the phase. However, based upon my past experience, if you don’t have some baseline for something that you decide to begin fighting for, you can barely have a measure on how much you have progressed when you actually start to fight, and highly likely, you may fall into the same trap over and over again for future similar situations.

Let’s dive into …

I have been considering getting a PhD since my sophomore year at University. This page summarizes some commonly-seen motivation for people getting a PhD. I think mine can be partly described as “Dr. Hu — sounds cool!” and “Eternal quest for knowledge (yeah right!)”. Another part, I guess, probably be the childhood dream of becoming a scientist. However, now, after two years working in industry, I realize that the most important motivation for me to get a PhD is that I want to have the ability to solve the problem that nobody explores before. This is different from quick learner because quick learner means grasping the material that has already studied before quickly. But, that doesn’t mean he can handle the unexplored area very well. I like to ask “why” when I face a problem but gradually I realize that I don’t have enough knowledge and more importantly, the confidence to solve some of crazy ideas in my mind. So, getting a PhD means I build some good knowledge foundation in some specific area and process the ability to solve any open question, even it is from the area that I haven’t explored before.

However, getting a PhD is a non-trivial task and itself demands lots of commitment. I personally view PhD and marriage are two the most serious commitment a person can ever give in his entire life. I try to play “rational” card here by doing some evaluation beforehand because I’m type of do-something-that-can-be-successful person and several years of study in economics make me become more and more like a “risk-averse” kind of person. So, I do various RA jobs in various departments (i.e. Math, Psychology, Biostatistics) to get a sense of what PhD life might look like.  The result is not good for me because I find out that working on some topics that you have the least interest in can be a lot like being in jail. However, those undergraduate research experience also has its positive side.  Imagine if I jump into the graduate school directly and choose some direction that I have no interest in (i.e. medical imaging),  I am sure that I cannot survive till the end. Sometimes I feel that the process of making decision is a two-way street: one way to do is to pick something that fits you from the pool; the other way is that you get rid of the choices that definitely do not work for you and then see what is left inside the pool. Apparently, for me, the latter strategy works slightly better.

So, I choose to work in industry for two years to find the things that I have passion about.
There isn’t much left in my choice pool by that time: I either pick from AI or from system.  For AI,  my focus is majorly on the application of ML techniques, such as CV, NLP. For system, my choice is distributed system (i.e. distributed database, distributed file system).  So, I need to carefully think about the pro and cons for which track I decide to pursue. Like I said in my offer choice post, there can hardly be a perfect choice that meets your need by any measure. Preference ranking in economics may be too ideal.  There is always trade-off. After spending two years working in database, I realize that I’m not really a hardcore system guy.  The most attractive feature from system is that I can do lots of coding. The coding here is naturally different from coding in, say, ML. In system, most of coding is done involves implementing data structures, data process models, and so on. However, for ML, coding is more like a direct translation of some mathematical formulas. However, the problem I find out about system research is that it is hard to propose problems that can directly link to the industry level production. This problem becomes clear to me after I attend DTCC 2017 last week.  The key success element for building a system is the production painpoints or user scenario. Alibaba and Tencent build system just to cater their specific business scenarios. In my view, the system has value once it can solve some specific problems that are not formed from someone’s imaginary. This can be very hard for newcomers who just join inside academic circle. In this case, advisor may work like a offer manager who regular visits companies to see what kind of problems they try to solve and bring those practical problems back to the research group and hopefully these issues can be resolved by his students. Research is all about solving problems and great research comes from the problems that have or potentially have great impact in the industry or people’s daily life.

In addition, if I recall the fun course experience from my undergraduate, I realize that I have much more fun with manipulating formulas and work out the problem that has strong connection with people’s daily life. The biggest trend right now is on big data. However, to be honest, for database system developer like me, I can barely get in touch with actual big data in my daily work. So, whether the system I build is robust enough to handle the actual big data, I don’t know. The only thing I can say is that I implement the design correctly. So, I feel like it is really hard to work out some good system by spending most of the time in school. This idea is partially confirmed by the trend that people jump out of academia and head to the industry like this.  However, even I have spent almost all the space so far talking about the “problems” I have observed about system research. I do enjoy the “traditional” programming scheme that system research possess. Rather than taking some data and train a somewhat blackbox network to achieve outcome, traditional if-else programming feels more rewarding for a hardcore programmer.

For AI, things can be radically different from system. Specifically for ML, one thing I learned is that ML is used to solve for the task that can hardly solvable by traditional programming, like autonomous driving, pattern recognition. Those stuff has strong connection to people’s daily life, which means can make a lot more impact. This is some historical pattern that can be easily observed: serving individual people is lot more profitable than serving big companies. Doing research on system is a lot like serving big companies if we consider the problem: who needs to build infrastructure from scratch? However, working on AI is a lot like serving people by making iPhones. If we observe the trend of companies like IBM and Apple, this analogy can easily work. So, even programming in ML is less satisfying in my sense, we just need to embrace the future to better maximize our utility.  Of course, mathematics are quite bit involved in the field of AI, and tweaking parameters of learning models can feel quite subjective. However, I guess that’s some obstacles I need to face. The rationale is same as before: there is no perfect choice and we just need to try even if we have only 10% confidence about success.

Last word …

The motivation for considering this issue right now is that I need to start planning my course schedule for the upcoming semester. The course schedule can be balanced between system and AI. But, it can also be AI focused. So, I really need to evaluate myself to see which direction I want to go.  There is a famous quote in China: “Choice matters!”

4 thoughts on “Thoughts on PhD

  1. 我发现我自己在做选择的时候也有点像你的思路:遍历所有options试图找到最优解。 所以我常常struggle,后来发现是自己常忽略的两个变量一个是我自己另一个是时间,因为不仅自己会变,很多事也会变。我后来觉得其实在life choice上很难找到最优解,it’s hard to predict all the ramifications of each choice. 你选择在读master期间多explore挺好的,希望一切顺利。 Anyways, 喜欢看你写的blog,很多可以relate。

    • 谢谢你的comment。选择过程中所消耗的时间确实是一个非常大的成本,而且确实往往被人所忽略。我发现很多时候之所以会很多时间和精力来试图找到“最优解”,其根本原因还是在于贪婪的天性和对自己不够了解。比如说我在选择方向上,AI和system这两个方向都有吸引我的地方,也有他们天生之于我的“不足”。我总是站在一个十字路口,往一条道路上走了几步,但又发现另一个地方风景的美好,又退了回来,迟迟无法抛弃另一条道路对我的诱惑。很多时候对options的穷尽对我而言从本质上就是希望能对自己有更深刻的了解。但是有的时候会发现选择一个差不多的往下走就好了,因为很快又会有一个选择的机会来帮助修正之前的“错误”。谢谢你的鼓励 🙂

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