## Sunday, August 31, 2014

### Sudoku and research

I got addicted to Sudoku... again. When I have a chance to rest, I enjoy the challenge of solving Sudoku puzzles (*cough* at the expert level) on my iPhone. I think this practice gives my mind sharpness and clarity (my wife would roll her eyes so hard if she heard me say this :-).

I was recently thinking of how the process of solving a Sudoku puzzle resembles doing research.

1) Sequencing is important. In Sudoku, you take things step by step. You fill out the obvious cells first. Having filled these, you now have more constraints/clues upon which you can fill in other blocks. You have to solve Sudoku step by step from most obvious to what is made obvious having finished that step.

This is also the case in research. You can't rush things; you should start with the simple steps. First you have to attack/complete what you can do currently, so that more things can become available for you to see. You have to climb the stair step by step to see more and do more.

2) Writing is important. You take notes on the Sudoku cells to give you clues, e.g., 4 can go into this cell or this cell. These clues eventually lead to constraints and to solutions. Without taking notes, you wouldn't be able to make any progress on hard Sudoku puzzles.

You are all computer scientists.
You know what FINITE AUTOMATA can do.
You know what TURING MACHINES can do.
For example, Finite Automata can add but not multiply.
Turing Machines can compute any computable function.
Turing machines are incredibly more powerful than Finite Automata.
Yet the only difference between a FA and a TM is that
the TM, unlike the FA, has paper and pencil.
It tells you something about the power of writing.
Without writing, you are reduced to a finite automaton.
With writing you have the extraordinary power of a Turing machine.

Similarly, writing is very important for research. It leads the way for you. You start writing as you start the research work, and before you do the work/experiments. I think I said this many times before, so I will leave this at that. (How I write, How to write your research paper, My advice to graduate students)

3) Perspective is important. In Sudoku, when you are stuck, you change your perspective and look for alternatives, because there is always another easier way to look at the situation and get unstuck.
A change in perspective is worth 80 IQ points.
Alan Kay.

CLAUDE SHANNON once told me that as a kid, he remembered being stuck on a jigsaw puzzle.
His brother, who was passing by, said to him:
"You know: I could tell you something."
That's all his brother said.
Yet that was enough hint to help Claude solve the puzzle.
I advise you, when you're stuck on a hard problem,
to imagine a little birdie or an older version of yourself whispering
"... I could tell you something..."
I once asked UMESH VAZIRANI how he was able,
to take 6 courses each and every semester.
He said that he knew he didn't have the time to work out his answers the hard way.
He had to find a shortcut.
You see, Umesh understood that problems often have short clever solutions.

In research, ... yup, you need to learn to change your perspective, and try different point of views.

4) Finally perseverance is important. In Sudoku, you learn patience and perseverance as you consider different things to make some progress. As you put in more time practicing Sudoku puzzles, you start noticing patterns, and you learn to solve those cases faster. You also develop intuition, which makes you get better at sequencing. In research, patience, perseverance, and practice are also essential.
Whatever you do, you got to like doing it....
You got to like it so much that you're willing to think about it, work on it, long after everyone else has moved on.