Archive for the 'Iterative' Category

Interview on Time Management and Future Book Projects

Baris: Effectively managing your to-do list is a big part of the Pomodoro Technique. I really like the simplicity of having a super simple list with items grouped as “now”, “today”, “later”. Is the “now list” your invention? Please tell me the thought process behind it.

Staffan: I think it’s my invention, even though many other people most certainly have similar concepts. Even if you decide to focus on just one thing, your thoughts easily starts to wander now and then. Writing the title of your current activity on a slip of paper and putting it next to the keyboard reminds you with in a fraction of a second what it was.

I’m interviewed by Baris Sarer. The full text is here:

  • Part one:
  • Part two:
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    What constitutes a Timebox, anyway?

    What constitutes a Timebox, anyway?

    I use the term Timebox when the following applies:

    1. I determined beforehand a particular point in time when it starts.
    2. I determined beforehand a particular point in time when it ends.
    3. I determined beforehand a particular activity that I will focus on.

    A successful Timebox is when I start at the time that I had determined (1), end at the time that I had determined (2) and only focus on the task that I had determined (3). As Timebox considered, it is irrelevant what, how much and with what quality I produce.

    There are alternatives to limit the time.

    • We can restrict the scope: pick blueberries in the woods until the bucket is full.
    • We can limit the quality: search the greengrocery until you have found a really good tomato.
    • We can limit the cost: shop christmas gifts until your wallet is empty.

    All four approaches have pros and cons.

    Pomodoro Technique Illustrated -- New book from The Pragmatic Programmers, LLC

    Regex process: Copy-Paste-Generalize

    Regular Expressions is a flexible tool for matching strings of text. They can be really crisp and elegant, but how can you design them? Below is a design process.




    Go from an idea to a flexible and generalized regular expression.


    You have a text example and you know what you want to extract. But, of course, you want your regular expression to be generalized enough to match other candidates.


    The Copy-Paste-Generalize pattern is easy to get you started and then you can develop your regular expression in an iterative and structured way.


    1. Copy a text example
    2. Paste it as your initial regular expression
    3. Generelaize the expression step by step until it matches any possible candidate

    Other Names

    This process has many names. E.g. Mehran Habibi call something similar “The Pull Technique” in his book Java Regular Expressions.


    Pomodoro Technique Illustrated info page at

    Pomodoro Technique Illustrated info page at presents a sale rank of all books. The list is updated frequently and every book’s current rank can be found at the book’s info page. Suppose I want to match the current rank for my book Pomodoro Technique Illustrated. First I download an example text: the current page at Amazon:

    I use Lynx (btw: by far the greatest web browser the world has ever seen) in CLI mode. The result is a rain of lines from Pomodoro Technique Illustrated‘s info page at Amazon. I better grep something to make my example text smaller:

    The result is:

    • * Amazon Bestsellers Rank: #23,032 in Books ([89]See Top 100 in

    Great! This includes what I want to match. What I’ve done so far is the Copy part of this process. Next goes the Paste. I add an extremely simple Regular Expression and put it in a Ruby one-liner:

    As a matter of fact, the expression that resides between the dashes is just a Paste of what I got from the Lynx dump. And the result of this line is:

    • 23,032

    …and that’s because of the parenthesis.

    Copy done. Paste Done. Let’s start to generalize. Next time I run this, I might get another rank than 23,032. Digits can be captured with the meta sequence \d. This implies the next iteration:

    Instead of cascading the \d, I can use the limiting repetition operator:

    The text in between “Rank” and the number may change. It would be more robust to describe it as non-digits:

    This expression will only work when the rank is between 1,000 and 999,999. Just in case this book gets extremely popular, let’s generalize the number part:

    The expression has become pretty compact and robust. I stop here:

    • Bestsellers Rank[^\d]*([\d,]*)


    Even though it’s only a example above, you may know how to make the Regular Expression or the Ruby/Bash code even more crisp. If you do, feel free to append a comment below.

    Pomodoro Technique Illustrated -- New book from The Pragmatic Programmers, LLC

    Do you ALWAYS respect the timebox?

    Timbox and Flow

    Timbox and Flow

    Hi Staffan! Do you ALWAYS respect the 25 minute timebox when you’re in the zone? Can’t this break your flow?

    Yes, I always respect the timebox:

    • A short break won’t make me forget everything. I can go on from exactly the point where I left.
    • The break means that I can recharge my brain. Goal free play encourages background processing and right brain thinking. If I put enough effort in last iteration, it will even be guilt free play, which helps me avoid procrastination.
    • Humans love rhythm. From the day we were born to the day we die, our life is filled with rhythms. They make us feel safe and helps us to have sustainable pace.
    • Flow means totally focused on one task. It doesn’t necessarily mean that I’m doing the most important task. Sometimes flow means efficiency, without effectiveness. To recurrently take a short break and then asses if I’m doing the most important thing will help me navigate in task land.
    • When I’m in the flow, I’m so focused so I’m not really aware that I’m in the flow. When the timebox is finished, it’s impossible to immediately say if I should continue or not.
    • To take a break when arousal is high, makes me eager when it’s time to start the next timebox.

    Am I supposed to focus now?

    Do you have trouble remembering if you’re in a Pomodoro or not? If you use a mechanical kitchen timer, the ticking sound will remind you. But what if you work in a no-sounds-allowed office?

    This is actually a very common problem. Even if you can’t have the ticking sound and the mechanical timer, I do believe that gestures are important. They help your brain to make the transition from free time to focus time and back.

    You may put your cell phone on the desk every time you start a Pomodoro and remove it when you end. Or even simpler: take a business card and color it green on the backside with a felt-tip pen. Put the card on your desk. Every time you start a Pomodoro, turn the green side up. Every time you end a Pomodoro, turn the green side down.

    • You can see the card/phone while you’re in a Pomodoro. It reminds you that it’s focus time.
    • The gestures of turning the card will—after a while—be associated with starting and ending a Pomodoro.

    Pomodoro Technique Illustrated -- New book from The Pragmatic Programmers, LLC

    Bibliography from Pomodoro Technique Illustrated

    There are many references in Pomodoro Technique Illustrated. Below is a list of the books in the bibliography linked to Amazon. In a future post I will also put links to the referred articles and web sites.

    How many of these have you read? Do you have any recommended reading for me?

    Pomodoro Technique Illustrated -- New book from The Pragmatic Programmers, LLC

    The Now List

    (This is an excerpt from the book Pomodoro Technique Illustrated)

    In 1933 Hedwig von Restorff performed a set of memory experiments. Her conclusion was that an isolated item, in a list of otherwise similar items, would be better remembered. If I read a shopping list with one
    item highlighted in azure blue, it’s more likely that I remember the highlighted item than any of the others. This is now identified as The
    Von Restorff effect

    The Now List is not another artifact in Pomodoro Technique® (created by Francesco Cirillo). It’s my name for a concept: what I give my attention to right now. The cardinality of my Now List is binary. Either I focus on 1 activity or 0 activities. It can
    never be 2, 3, 4 or any other number of activities. Before I wind up the clock, I choose one single activity. My challenge during a 25 minute Pomodoro is to not give another activity attention for a minute or two.

    The Von Restorff effect tells me that I can provoke my memory to store things that I highlight. I may use a highlighter felt-tip pen to mark the current activity on the To Do Today sheet. Or I can explicitly write the
    activity title on a slip of paper and put it in front of me.

    The Now List

    The Now List

    Pomodoro Technique Illustrated -- New book from The Pragmatic Programmers, LLC