An Informal Learner Using Repetition Spacing Software

Brisbane Programmer and SuperMemo User Chris Khoo

Brisbane Programmer and SuperMemo User Chris Khoo

On May 6, I posted on the Wired piece on

Piotr Wozniak, the polymath inventor of SuperMemo, a software system which promises to help remember forever the things that you’ve learned. Then July 20, Chris Khoo, a 26-year-old enterprise software developer in Brisbane challenged the post in the comments saying in effect, isn’t it better to remember than have to keep relearning stuff. Chris has been using SuperMemo for several months now and I asked him to comment on his experience.

Here then is an online interview with SuperMemo user Chris Khoo. 

  1. Tell me about yourself. Where do you live? What you do you do? What’s your age? Where did you go to college (if indeed you did) and what did you study? The usual. 

Based in Brisbane, Australia.  26.  Studying university part time doing Business & IT & working full time doing enterprise software development at a big company.


  1. What were the circumstances when you first started using repetition spacing software? 

Supermemo was mentioned on a forum, and I started reading more about it on  After being fairly convinced that the methodology was sound, I gave it a go and after awhile, really got to enjoy using it daily.


  1. Which product do you use? 



  1. How did you choose it over the other options? 

Hmmm… I chose it mainly because I found Piotr’s website to be very open and informative (especially his articles on sleep & learning – I could relate it to my experiences on polyphasic sleep).  I did some quick evaluations of the paid & open source alternatives, and other blogs tend to mention that they chose other products because they feel they didn’t need the bells & whistles of Supermemo.


Although I didn’t initially understand the need for some of the features in Supermemo, I found Piotr’s writings to be very sound and fluff-free.  I tried the free Supermemo 98 for a few weeks, and then went and bought a license for 2006.  I then persisted with it and over time have grown to understand and appreciate some of the features like incremental reading.  So I’m very happy I made the decision to go with Supermemo.


  1. How long have you been using it? 

2-3 months now.


  1. The reputation of Piotr Wozniak’s SuperMemo is that the software is difficult to master. What’s been your experience with the repetition spacing software that you use? 

It definitely takes lots of time initially.  I’ve found that I needed to frequently change how questions are phrased over the first few weeks – just to learn how to ask the right questions which give some context without giving the answer away.


I also found personally that auditory questions that triggered visual memories increased my recall dramatically – I’ve come to realise this is more natural since when people ask you questions verbally, this should trigger some sort of visual in your head.


I probably spend on average 1-2hrs a day at the moment.  I expect this to remain fairly constant for awhile as I’m studying @ university.


I have spent up to 4 hours one day on the weekends, but that was doing alot of reorganising & rephrasing of questions.


It’s like any new hobby/skill – you spend a truckload of time on it initially to get to a decent standard, and then slowly taper off to a maintenance level. 


  1. How does the repetition spacing software actually work, in your experience? 

Not difficult really.  It ask questions you’ve added, you think of the answer, click a button to show the answer, and then rate how well you think you went.  Based on your rating, the system will determine when to ask you the question again.


  1. In your comment you said that not having to relearn stuff you already ostensibly know allows you to devote more time to creative endeavors. What creative endeavors do you now give fuller expression to than before? 

As a software developer, I can sit and code without having to look up documentation as much as before.  This gives my mind alot of room to think through things and essentially manipulate code in my mind without writing it down on paper.  I used to always have to write things down on paper, and now I rarely do it.  I can’t definitively say it’s a causative relationship – i.e. not having to relearn stuff made me more creative, but I’m alot quicker than before at my work.


  1. What kind of demands on your time does the repetition spacing software place? 

At the moment, 1-2hrs a day.  I expect this to slowly come down to 1hr as I become settled on how to write good questions and as the existing questions space themselves out more as I recall them better.


  1. Do you recall memorized stuff at 90 percent recall as advertised? If not, what would you say your recall is? How do you test your recall? 

There’s a statistics option which says my retention is 88%.  I haven’t measured it rigorously but anecdotally, I know my memory’s improved.


  1. What other kind of advantages does remembering well confer? I got to believe there’s some bar games you’re really good at.  

I definitely have more confidence now.  I can rattle off memorised material at work meetings and people have noticed the improvement.


  1. Have you ever tried going on a game show? If so, what happened? 

No – never intend to.  I enjoy programming too much to devote my mind to other pursuits at this stage.


  1. What’s the breadth of the memory? That is, are you good at remembering number sequences, or faces, or the periodical chart, or how to conjugate verbs in Latin? 

Haha, I guess the software is an aid really.  I’m not sure of your programming knowledge, but there’s a fairly cryptic language called “regular expressions”, which is almost like shorthand for validating bits of text.


To give you an example of how weird it can look, something really simple like /^\d{7}$/ means that you can only enter a 7 digit number (maybe a phone number).  I rattled off some expressions during a work meeting because I could remember the characters in my head.  Most people would usually use some sort of helper software to help them write up up their regular expressions.


Right now, I’m also slowly developing a mnemonic system based on associating 3 digit numbers with images.  And I’m using those images to remember friends’ and family mobile numbers.  Although you can rely on your phone’s phonebook to store them, I find it’s a neat way to learn the images so I can eventually build a system where I can memorise and recall numbers easily.  Repetition spacing software definitely makes the process more meaningful & efficient.


  1. Are there strange holes in your recall? For instance, do you have trouble remembering what kind of dog food your dog likes, or your mother’s birthday? That kind of stuff. 

Funny you mention that.  I found that both short term & long term memory have improved.


I used to remember that every time I go to bed, I would start to worry about 5 minutes in thinking whether I switched on my alarm or not.  That doesn’t happen anymore.  It seems like I can remember things I did earlier in the day alot better than before.


And for the long term, if I want to remember something, I just put it into Supermemo.  I don’t just do facts and figures.  I’ve got personal questions about username/passwords, questions about people’s birthdays, and as mentioned before, people’s phone numbers.


  1. Anything else I oughta know or that you want to share? 

It’s hard.  Like Piotr says on the website, it’s mentally taxing when trying to recall.  The best time to do it is in the morning, and don’t start off doing 1 hour recall sessions.  Probably best to limit it to 30mins for a week or so before ramping up.


It’s actually amazing how much brain energy recalling takes.  It made me realise most of us are so mentally unfit today because of things like PDAs & Google.


Tags: , , ,

2 Responses to “An Informal Learner Using Repetition Spacing Software”

  1. Got Any Informal Learning Goals This Year? | Mark McClure Today Says:

    […] the final, sentence in this revealing interview with Chris Khoo, a Brisbane-based programmer and user of a software tool which claims to help you […]

  2. Mr. Spock Can’t Forget the Theme to Gilligan’s Island Either « Thelearnersguild’s Weblog Says:

    […] Unless you work at it by keeping a learner’s journal and frequently reviewing it, or using a repetition spacing software like SuperMemo, it crumbles like […]

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: