Toronto Data Science Meetup – Machine Learning for Humans

A little while ago I spoke again at the Toronto Data Science Group, and gave a presentation I called “Machine Learning for Humans”:

I had originally intended to cover a wide variety of general “gotchas” around the practical applications of machine learning, however with half an hour there’s really only so much you can cover.

The talk ended up being more of an overview of binary classification, as well as some anecdotes around mistakes in using machine learning I’ve actually seen in the field, including:

  • Not doing any model evaluation at all
  • Doing model evaluation but without cross-validation
  • Not knowing what the cold start problem is and how to avoid it with a recommender system
All in all it was received very well despite being review for a lot of people in the room. As usual, I took away some learnings around presenting:
  • Always lowball for time (the presentation was rushed despite my blistering pace)
  • Never try to use fancy fonts in Powerpoint and expect them to carry over – it never works (copy paste as an image instead when you’ve got the final presentation)
Dan Thierl of Rubikloud gave a really informative and candid talk about what product management at a data science startup can look like. In particular, I was struck by his honesty around the challenges faced (both from technical standpoint and with clients), how quickly you have to move / pivot, and how some clients are just looking for simple solutions (Can you help us dashboard?) and are perhaps not at a level of maturity to want or fully utilize a data science solution.
All in all, another great meetup that prompted some really interesting discussion afterward. I look forward to the next one. I’ve added the presentation to the speaking section.

Big Data Week Toronto 2014 Recap – Meetup #3: Big Data Visualization

This past week was Big Data Week for those of you that don’t know, a week of talks and events held worldwide to “unite the global data communities through series of events and meetups”.

Viafoura put on the events this year for Toronto and was kind enough to extend an invitation to myself to be one of the speakers talking on data visualization and how that relates to all this “Big Data” stuff.

Paul spoke detecting fraud online using visualization and data science techniques. Something I often think about when presenting is how to make your message clear and connect with both the least technical people in the audience (who, quite often, have attended strictly out of curiosity) and the most knowledgeable and technically-minded people present.

I was really impressed with Paul’s visual explanation of the Jaccard coefficient. Not everyone understands set theory, however almost everyone will understand a Venn diagram if you put it in front of them.

So to explain the Jaccard index as a measure of mutual information when giving a presentation, which is better? You could put the definition up on a slide:

 J(A,B) = {{|A cap B|}over{|A cup B|}}.
which is fine for the mathematically-minded in your audience but would probably lose a lot of others. Instead, you could use a visualization like this figure Paul included:
The two depict the same quantity, but the latter is far more accessible to a wide audience. Great stuff.
I spoke on “Practical Visualizations for Visualizing Big Data” which included some fundamentals (thinking about data and perception in visualization / visual encoding) and the challenges the three “V”s of Big Data present when doing visualization and analysis, and some thoughts on how to address them.
This prompted some interesting discussions afterward, I found most people were much more interested in the fundamentals part – how to do visualization effectively, what constitutes a visualization, and the perceptional elements of dataviz and less on the data science aspects of the talk.
Overall it was a great evening and I was happy to get up and talk visualization again. Thanks to the guys from Viafoura for putting this on and inviting me, and to the folks at the Ryerson DMZ for hosting.
Mini-gallery culled from Twitter below:

Toronto Data Science Group – A Survey of Data Visualization Techniques and Practice

Recently I spoke at the Toronto Data Science group. The folks at Mozilla were kind enough to record it and put it on Air, so here it is for your viewing pleasure (and critique):


Overall it was quite well received. Aside from the usual omg does my voice really sound like that?? which is to be expected, a couple of thoughts on the business of giving presentations which were quite salient here:

  • Talk slower and enunciate
  • Gesture, but not too much
  • Tailor sizing and colouring of visuals, depending on projection & audience size

I’ve reproduced the code which was used to create the figures made in R (including the bubble chart example, with code and data from FlowingData), which regrettably at the time I neglected to save. Here it is in a gist:

The visuals are also available on Slideshare.

Lessons learned: talk slower, always save your code, and Google stuff before starting – because somebody’s probably already done it before you.

Quantified Self Toronto #15 – Text Message Analysis (rehash)

Tonight was Quantified Self Toronto #15.

Eric, Sacha and Carlos shared about what they saw at the Quantified Self Conference in California.

I presented my data analysis of a year of my text messaging behaviour, albeit in slidedeck form.

Sharing my analysis was both awesome and humbling.

It was awesome because I received so many interesting questions about the analysis, and so much interesting discussion about communications was had, both during the meeting and after.

It was humbling because I received so many insightful suggestions about further analysis which could have been done, and which, in most cases, I had overlooked. These suggestions to dig deeper included analysis of:

  • Time interval between messages in conversations (Not trivial, I noted)
  • Total amount of information exchanged over time (length, as opposed to the number of messages)
  • Average or distribution of message length per contact,  and per gender
  • Number of messages per day per contact, as a measure/proxy of relationship strength over time
  • Sentiment analysis of messages, aggregate and per contact (Brilliant! How did I miss that?)

Again, it was quite humbling and also fantastic to hear all these suggestions.

The thing about data analysis is that there are always so many ways to analyze the data (and make data visualizations), and it’s what you want to know and what you want to say that help determine how to best look at it.

It’s late, and on that note, I leave you with a quick graph of the weekly number of messages for several contacts, as a proxy of relationship strength over time (pardon my lack of labeling). So looking forward to the next meeting.

Carlos Rizo, Sacha Chua, Eric Boyd and Alan Majer are the organizers of Quantified Self Toronto. More can be found out about them on their awesome blogs, or by visting quantifiedself.ca

Zzzzzz….. – Quantified Self Toronto #14

Sleep is another one of those things like diet, where I feel if you asked anyone if they wanted to improve that area of their life most would say yes.

I remember hearing a quote that sleep is like sex; no one is quite sure how much everyone else is getting, but they are pretty sure it is more than them. Or wait, I think that was salary. With sleep it is more like – no one is quite sure how much they should be getting, but they sure as hell wish they were getting a lot more.

A lot of research has been done on the topic and it seems like the key takeaway from it is always the same: we are not getting enough sleep and this is a problem.

I know that I am a busy guy, that I am young, and that I go out on the weekends, so I know for a fact that my sleep is ‘bad’. But I was curious as to how ‘bad’ it actually is. I started tracking my sleep in April to find out, and also to see if there were any interesting patterns in it of which I was not aware.
 
I spoke again at Quantified Self Toronto (#14) (I spoke previously at #12 on June 7th) about it on August 7th. I gave an overview of my sleep-tracking activities and my simple examination of the data I had gathered. Here is the gist of my talk, as I remember it.

Hi everyone, I’m Myles Harrison and this is my second time speaking at Quantified Self Toronto, and the title of my second presentation is ‘Zzzzzzzz….’. 

I started tracking how much I was sleeping per night starting in April of this year, to find out just how good or bad my sleep is, and also to see if there are any patterns in my sleep cycle.

Now I want to tell you that the first thing I thought of when I started to putting this slide deck together was Star Trek. I remember there was the episode of Star Trek called ‘Deja Q’. Q is an omnipotent being from another dimension that torments the crew of the Enterprise for his own amusement, and in this particular episode he becomes mortal. In one part of the episode he is captured and kept in a cell onboard the ship, and he describes a terrible physical experience he has:

Q
I have been entirely preoccupied by a most frightening experience of my own. A couple of hours ago, I started realizing this body was no longer functioning properly… I felt weak, the life oozing out of me… I could no longer stand… and then I lost consciousness…

PICARD
You fell asleep.

Q
It’s terrifying…. how can you stand it day after day?

PICARD
One gets used to it…


And this is kind of how I have always felt about sleep: I may not like it, there are many other things I’d rather be doing during all those hours, however it’s a necessary evil, and you get used to it. If I could be like Kramer on Seinfeld and try to get by on ‘Da Vinci Sleep’, I probably would. However for me, and for most of the rest of us, that is not a reasonable possibility.

So now we come to the question of ‘how much sleep do we really need?’. Obviously there is a hell of a lot of research which has been done on sleep, and if you ask most people how much sleep they need to get every night, they will tell you something like ‘6-8 hours’. I believe that number comes from this chart which is from the National Sleep Foundation in the States. Here they give the figure of 7-9 hours of sleep for an adult, however this is an average. If you read some of the literature you will find, unsurprisingly, that the amount of sleep needed depends on a lot physiological factors and so varies from person to person. Some lucky people are perfectly capable of functioning normally during the day on only 3 or 4 hours of sleep a night, whereas some other unlucky people really need about 10 to 12 hours of sleep a night to feel fully rested. I highly doubt these unlucky folks regularly get that much sleep a night, as most of us have to get up in the morning for this thing called ‘work’. So yes, these are the extremes but they serve to illustrate the fact that this 6-8 (or 7-9) hours per night figure is an average and is not for everyone.

Also I found a report compiled by Statistics Canada in 2005 which says that the average Canadian sleeps about 8 and a half hours a night, usually starting at about 11 PM. Additionally, most Canadians get about 20 extra minutes of sleep on weekend nights as they don’t have to go to work in the morning and so can hit the snooze button.

So knowing this, now I can look at my own sleep and say, how am I doing and where do I fit in?


So as I said, I have been recording my sleep since early April up until today. In terms of data collection, I simply made note of the approximate time I went to bed and the approximate time at which I woke up the following morning, and recorded these values in a spreadsheet. Note that I counted only continuous night-time sleep and so the data do not include sleep during the day or things napping [Note: this is the same as the data collected by StatsCan for the 2005 report]. Also as a side interest I kept a simple yes/no record of whether or not I had consumed any alcohol that evening, counting as a yes any evening on which I had a drink after 5 PM.

O
n to the data. Now we can answer the question ‘What does my sleep look like?’ and the answer is this:

There does not appear to be any particular rhyme or reason to my sleep pattern. Looking at the graph we can conclude that I am still living like a University student. There are some nights where I got a lot of sleep (sometimes in excess of 11 or 12 hours) and there are other nights where I got very, very little sleep (such as this one particular night in June where I got no sleep at all, but that is another story). The only thing I can really pick out of this graph of note is that following nights or sequences of nights where I got very little sleep or went to bed very late, there is usually a night where I got a very large amount of sleep. Interestingly this night is sometimes not until several days later but this may be due to the constraints of the work week.

So despite the large amount of variability in my sleep we can still look at it and do some simple descriptive statistics and see if we can pull any meaningful patterns out of it. This is a histogram of the number of hours of sleep I got each night.

Despite all the variability in the data from what we saw earlier, it looks like the amount of sleep I get is still somewhat normally distributed. It looks like I am still getting about 7 hours of sleep on average, which actually really surprised me and in my opinion is quite good, all things considered and given the chaotic nature of my personal life. [Note: the actual value is 6.943 hrs for the mean, 7 for the median with a standard deviation of 1.82 hours]. 

So we can ask the question, ‘Is my amount of nightly sleep normally distributed?’. Well, at first glance it sure appears like it might be. So we can compare to what the theoretical values should be, and this certainly seems to be the case, though using a histogram is maybe not the best way as it will depend on how you choose your bin sizes.


We can also look at what is called a Q-Q plot which plots the values against the theoretical values, and if the two distributions are the same then the values should lie along that straight line. They do lie along it well, with maybe a few up near the top there straying away… so perhaps it is a skew-normal distribution or something like that, but we can still safely say that the amount of sleep I get at night is approximately normally distributed.


Okay, so that is looking at all the data, but now we can also look at the data over the course of the week, as things like the work week and weekend may have an affect on how many hours of sleep I get.

So here is a boxplot of the number of hours of sleep I got for each day of the week and we can see some interesting things here.

Most notably, Wednesday and Saturday appear to be the ‘worst’ nights of the week for me for sleep. Saturday is understandable, as I tend to go out on Saturday nights, and so the large amount of variability in the number of hours and low median value is to be expected; however, I am unsure as to why Wednesday has less hours than the other days (although I have do go out some Wednesday nights). Tuesdays and Thursdays appears to be best both in terms of variability and the median amount, these days being mid-week where presumably my sleep cycle is becoming regular during the work week (despite the occasional bad Wednesday?).

We can also examine when I feel asleep over the course of the week. Wait, that sounds bad, like I am sleeping at my desk at work. What I mean is we can also examine what time I went to bed each night over the course of the week:

Again we can see some interesting things. First of all, it is easy to note that on average I am not asleep before 1 AM! Secondly we can see that I get to sleep latest on Saturday nights (as this is the weekend) and that there is a large amount of variability in the hour I fall asleep on Fridays. But again we see that in terms of getting to bed earliest, Wednesday and Saturday are my ‘worst’ days, in addition to being the days when I get the least amount of sleep on average. Hmmmmmm….! Could there be some sort of relationship here?

So we can create a scatterplot and see if there exists a relationship between the hour at which I get to bed and the number of hours of sleep I get. And when we do this we can see that there is appears to be [surprise, surprise!] a negative correlation between the hour at which I get to sleep and the number of hours of sleep I get.

And we can hack a trend line through there to verify this:

> tl1 <- lm(sleep$hours ~ starthrs)
> summary(tl1)

Call:
lm(formula = sleep$hours ~ starthrs)

Residuals:
    Min      1Q  Median      3Q     Max
-7.9234 -0.6745 -0.0081  0.5569  4.8669

Coefficients:
            Estimate Std. Error t value Pr(>|t|)   
(Intercept)  9.78363    0.43696  22.390  < 2e-16 ***
starthrs    -0.62007    0.09009  -6.883 3.56e-10 ***

Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 1.533 on 112 degrees of freedom
Multiple R-squared: 0.2973,    Adjusted R-squared: 0.291
F-statistic: 47.38 on 1 and 112 DF,  p-value: 3.563e-10

So there is a highly statistically significant relationship between how late I get to sleep and the number of hours of sleep I get. For those of you that are interested, the p-value is very small (on the order of e-10). However you can see that the goodness of fit is not that great, as the R-squared about 0.3. This means that perhaps there are other explanations as to why getting to sleep later results in me getting less sleep, however I could not immediately think of anything. I am open to other suggestions and interpretations if you have any.

Also I got to thinking that this is the relationship between how late I get to sleep and how much sleep I get for all the data. Like a lot of people, I have a 9 to 5, and so I do not have the much choice about when I can get up in the morning. Therefore I would expect that this trend is largely dependent upon the data from the days during the work week.

So I thought I would do the same examination only for the days of the week where the following day I do not have to be up by a certain hour, that is, Friday and Saturday nights. And we can create the same plot, and:

We can see that, despite there being less data, there still exists the negative relationship.

> tl2 <- lm(wkend$hours ~ hrs)
> summary(tl2)

Call:
lm(formula = wkend$hours ~ hrs)

Residuals:
    Min      1Q  Median      3Q     Max
-5.4288 -0.4578  0.0871  0.5536  4.4300

Coefficients:
            Estimate Std. Error t value Pr(>|t|)   
(Intercept)  12.1081     0.9665  12.528 1.89e-13 ***
hrs          -0.8718     0.1669  -5.224 1.24e-05 ***

Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 1.737 on 30 degrees of freedom
Multiple R-squared: 0.4764,    Adjusted R-squared: 0.4589
F-statistic: 27.29 on 1 and 30 DF,  p-value: 1.236e-05

So it appears that on the days on which I could sleep in and make up the hours of sleep I am losing by going to bed later I am not necessarily doing so. Just because I can sleep in until a ridiculously late hour doesn’t necessarily mean that my body is letting me do so. This came as a bit of a surprise to me, as I thought that if I didn’t have to be up at a particular hour in the morning to do something, I would just sleep more to make up for the sleep I lost. An interesting insight – even though I can sleep in and make up for hours lost doesn’t necessarily mean that I will. 

So basically I just need to get to sleep earlier. Also, I am reminded of what my Dad always used to say to me when I was a kid, ‘An hour of sleep before midnight is worth two afterwards.’

Lastly, as I said, I did keep track of which nights I had consumed any alcohol in the evening to see what impact, if any, this was having on the quality and duration of my sleep. For this I just did a simple box plot of all the data and we can see that having a drink does mean I get less sleep overall.


Though this is a very simple overview it is consistent with what you can read in the research done on alcohol consumption and sleep. The belief that having a drink before bed will help you sleep better is a myth, as alcohol changes physiological processes in the body which are necessary for a good night’s sleep, and disrupts it.


So those were the conclusions I drew from tracking my sleep and doing this simple analysis of it. In terms of future directions, I could also further quantify my tracking of my sleep. I have simply measured the amount of sleep I have been getting, going with the assumption that getting close to the recommended amount of time is better. I could further quantify things by rating how rested I feel when I awake (or during the day) or rating how I felt the quality of rest I got was, on a scale of 1-10.

I could also measure other factors, such eating and exercise, and the time these things occur and how this play in to the amount and quality of the sleep I get.

Lastly, though I did have a simple yes/no measurement for whether or not I had consumed alcohol each evening, I did not quantify this. In the future I could measure caffeine consumption as well, as this known to be another important factor affecting sleep and restfulness.

That concludes my presentation, I hope I kept you awake. I thank you for your time, and for listening. If you have any questions I would be happy to answer them.

References & Resources 

National Sleep Foundation
http://www.sleepfoundation.org/

Who gets any sleep these days? Sleep patterns of Canadians (Statistics Canada)
http://www.statcan.gc.ca/pub/11-008-x/2008001/article/10553-eng.htm

The Harvard Medical School’s Guide to A Good Night’s Sleep
http://books.google.ca/books?id=VsOWD6J5JQ0C&lpg=PP1&pg=PP1#v=onepage&q&f=false

Quantified Self Toronto
http://quantifiedself.ca/

How much do I weigh? – Quantified Self Toronto #12

Recently I spoke at the Quantified Self Toronto group (you can find the article on other talk here).

It was in late November of last year that I decided I wanted to lose a few pounds. I read most of The Hacker’s Diet, then began tracking my weight using the excellent Libra Android application. Though my drastic reductions of my caloric intake are no more (and so my weight is now fairly steady) I continue to track my weight day-to-day and build the dataset. Perhaps later I can do an analysis of the patterns in fluctuations in my weight separate from the goal of weight loss.

What follows is a rough transcription of the talk I gave, illustrated by the accompanying slides.

Hello Everyone, I’m Myles Harrison and today I’d like to present my first experiment in quantified self and self-tracking. And the name of that experiment is “How Much Do I Weigh?”

So I want to say two things. First of all, at this point you are probably saying to yourself, “How much do I weigh? Well, geez, that’s kind of a stupid question… why don’t you just step on a scale and find out?” And that’s one of the things I discovered as a result of doing this, is that sometimes it’s not necessarily that simple. But I’ll get to that later in the presentation.

The second thing I want to say is that I am not fat.

However, there are not many people whom I know where if you ask them, “Hey, would you like to lose 5 or 10 pounds?” the answer would be no. The same is true for myself. So late last November I decided that I wanted to lose some weight and perhaps get into slightly better shape. Being the sort of person I am, I didn’t go to the gym, I didn’t go a personal trainer, and I didn’t meet with my doctor to discuss my diet. I just Googled stuff. And that’s what lead me to this

The Hacker’s Diet, by John Walker. Walker was one of the co-founders of the company Autodesk which created the popular Autocad software and later went on to become a giant multinational company. Mr. Walker woke up one day and had a realization. He realized that he was very successful, very wealthy, and had a very attractive wife, but he was fat. Really fat. And so John Walker though, “I’ve used my intelligence and analytical thinking to get all these other great things in my life, why can’t I apply my intelligence to the problem of weight, and solve it the same way?” So that’s exactly what he did. And he lost 70 pounds.

Walker’s method was this. He said, let’s forget all about making this too complicated. Let’s look at the problem of health and weight loss as an engineering problem. So there’s just you:

and your body is the entire system, and all this system has, the only things we’re going to think about are inputs and outputs. I don’t care if you’re eating McDonald’s, or Subway, or spaghetti 3 times a day. We’re just talking about the amount of input – how much? Therefore, from this incredibly simplified model of the human body, the way to lose weight is just to ensure that the inputs are less than the outputs.

IN < OUT

Walker realized that this ‘advice’ is so simple and obvious that it is nearly useless in itself. He compared it to the wise financial guru, on being asked how to make money on the stock market by an apprentice, giving the advice: “It’s simple, buy low and sell high.” Still, this is the framework we have as a starting point, so we proceed from here.

So now this raises the question, “Okay well how do we do that?” Well, this is a Quantified Self meet up, so as you’ve probably guessed, we do it by measuring.

We can measure our inputs by counting calories and keeping track of how much we eat. Measuring output is a little more difficult. It is possible to approximate the number of calories burned when exercising, but actually measuring how much energy you are using on a day-to-day basis, just walking around, sitting, going to work, sleeping, etc. is more complicated, and likely not practically possible. So instead, we measure weight as a proxy for output, since this is what we are really concerned with in the first place anyhow. i.e. Are we losing weight or not?

Okay, so we know now what we’ve got to do. How are we going to keep track of all this? Walker, being a technical guy, suggests entering all the information into a piece of computer software, oh, say, I don’t know, like a certain spreadsheet application. This way we can make all kinds of graphs and find the weighted moving average, and do all kinds of other analysis. But I didn’t do that. Now don’t get me wrong, I love data and I love analyzing it, and so I would love doing all those different types of things. However, why would I use a piece of software that I hate (and am forced to on a regular basis) any more than I already have to? Especially when this is the 21st century and I have a perfectly good smartphone and somebody already wrote the software to do it for me!

So, I’m good! Starting in late November of last year I followed the Hacker’s Diet directions and weighed myself every day (or nearly every day, as often as I could) at approximately the same time of day. And along the way, I discovered some things.

One day I was at work and I got a text from my roommate, and it said “Myles, did you draw a square on the bathroom floor in black permanent marker?” To which I responded, “Why yes I did.” To which the response was “Okay, good.” And the reason I that I drew a square on the tiles of the bathroom floor in black permanent marker was because of observational error. More specifically, measurement error. 

If you know anything about your typical drugstore bathroom scale you probably know that they are not really that accurate. If you put the same scale on an uneven surface (say, like tiles on a bathroom floor) you can make the same measurement back-to-back and get wildly different values. That is to say the scales have a lot of random error in their measurement. And that’s why I drew that square on the bathroom floor. That was my attempt to control measurement error, by placing the scale in as close to the same position I could every morning when I weighed myself. Otherwise you get into this sort of bizarre situation where you start thinking, “Okay, so is the scale measuring me or am I measuring the scale?” And if we are attempting to collect some meaningful data and do a quantified self experiment, that is not the sort of situation we want to be in.

So I continued to collect data from last November up until today. And this is what it looks like.

As you can see like most dieters, I was very ambitious at the start and lost approximately 5 pounds between late November and and the tail end of December. That data gap, followed by a large upswing corresponds to the Christmas holidays, when I went off my diet. After that I continued to lose weight, albeit somewhat more gradually up until about mid-March, and since then I have ever-so-slowly been gaining it back, mostly due to the fact that I have not been watching my input as much as I was before.

So, what can we take away from this graph? Well, from my simple ‘1-D’ analysis, we can see a couple of things. The first thing, which should be a surprise to no one, is that it is a lot easier to gain weight than it is to lose it. I think most everyone here (and all past dieters) already knew that. 

Secondly, my diet aside, it is remarkable to see how much variability there is in the daily measurements. True, some of this may be due to the aforementioned measurement error, however in my readings online I also found that a person’s weight can vary by as much as 1 to 3 pounds on a day-to-day basis, due to various biological factors and processes.

Walker comments on this variability in the Hacker’s Diet. It is one of his reasons as to why looking at the moving average and weighing oneself every day is important, if you want to be able to really track whether or not a diet is working. And that’s why doing things like Quantified Self are important, and also what I was alluding to earlier when I said that the question of “How much do I weigh?” is not so simple. It’s not simply a matter of stepping on the scale and looking at a number to see how much you weigh. Because that number you see varies on a daily basis and isn’t a truly accurate measurement of how much you ‘really’ weigh.

!

This ties into the third point that I wanted to draw from the data. That point is that the human body is not like a light switch, it’s more like a thermostat. I remember reading about a study which psychologists did to measure people’s understanding of delayed feedback. They gave people a room with a thermostat, but there was a delay in the thermostat, and it was set to something very very high, on the order of several hours. The participants were tasked with getting to room to stay at a set temperature, however none of them could. Because people (or most people, anyhow) do not intuitively understand things like delayed feedback. The participants in the study kept fiddling with the thermostat and setting it higher and lower because they thought it wasn’t working, and so the temperature in the room always ended up fluctuating wildly. The participants in the study were responding to what they saw the temperature to be when they should have been responding to what the temperature was going to be.

And I think this is a good analogy for the problem with dieting and why it can be so hard. This is why it can be easy to become frustrated and difficult to tell if a diet is working or not. Because if you just step on the scale every day and look at that one number, you don’t see the overall picture, and it can be hard to tell whether you’re losing weight or not. And if you just see that one number you’d never realize that though I can eat a pizza today and I will weight the same tomorrow, it’s not until 3 days later that I have gained 2 pounds. It’s a problem of delayed feedback. And that’s one of the really interesting conclusions I came to ask a result of performing this experiment.

So where does this leave us for the future?

Well, I think I did a pretty good job of measuring my weight almost every day and was able to make some interesting conclusions from my simple ‘1-D’ analysis. However, though I did very well tracking all the output, and did not track any of my inputs whatsoever. In the future if I kept track of this as well (for instance by counting calories) I would have more data and be able to draw some more meaningful conclusions about how my diet is impacting my weight.

Secondly, I did not do one other thing at all. I didn’t exercise. This is something Walker gets to later in his book too (like most diet/health books) however I did not implement any kind of exercise routine or measurement thereof.

In the future I think if I implement these two things, as well as continuing with my consistent measurement of my weight, then perhaps I could ‘get all the way there’

 

|—————| 100%

 
That was my presentation, thank you for listening. If you have any questions I will be happy to answer them.

References / Resources

Libra Weight Manager for Android
https://play.google.com/store/apps/details?id=net.cachapa.libra 

The Hacker’s Diet
http://www.fourmilab.ch/hackdiet/www/hackdiet.html 

Quantified Self Toronto
http://quantifiedself.ca/ 

rhok (n’ roll)

This past weekend was rhok Toronto which was a fun, exhausting, educational, and all around amazing weekend which I was honoured to be involved in.

The team I was fortunate enough to be a part of produced a prototype web-service to promote fair housing, and improve the ease of the submission process for investigations into housing by-law violations. An added bonus was that this resulted in this nice visualization of more City of Toronto data.

You can learn more about rhok here.