Nick Winter’s Big Success with Percentile Feedback

I have posted several times about using what I call percentile feedback to boost productivity. Percentile feedback means comparing your current performance to your previous performance using a percentile. If the current performance is in the middle of your previous performances, the percentile is 50, for example. Percentile feedback is easy to understand (scores above 50 are better than average) and is sensitive to small improvements — so even small improvements are rewarded. My implementation had three other helpful features: 1. It adjusted for the time I woke up to make different days more comparable. 2. It measured efficiency (time working/time available) to further improve comparability across days. 3. It was graphical. I made a graph of efficiency throughout the current day versus previous days. It greatly increased how much I worked every day.

I love it and wish I had it for everything I measure. Unlike so many feedback systems, it is realistic and encouraging. I found it worked extremely well — to my surprise, actually. It’s not so surprising I would think of it because it vaguely resembles an animal-learning procedure. (Animal learning is my area of expertise within psychology.)

Nick Winter, one of the developers of Skritter (which I use), recently started to use it. He gave a much-too-short QS talk about it in Pittsburgh a month ago. I asked him about his experience. He is as enthusiastic as I am. He wrote:

The percentile feedback has been a huge success–I’m getting way more done than I ever did, and I’m much better at prioritizing toward my main project. Seeing the graph going in real time has been much better at making me aware of what I need to do to hit high targets each day. I will do a full writeup on this, and on my self experiments, when I finish this iOS app and stop focusing so much on work. The short teaser goes something like this:
Phase 0: just tracking normal work at end of day in a Google Doc, average 2 hours a day on iOS development
Phase 1: tracking normal work and iOS dev separately in the Google Doc, average 4 hours a day on iOS development
Phase 2: using Beeminder to have better graphing and goal incentive for iOS dev, average 5 hours a day
Phase 3: first three weeks of using percentile feedback, average 6.4 hours a day
Phase 4: second three weeks of using percentile feedback, deciding to really push it based on the positive feedback from my metrics (more productivity, more happiness), average 9.4 hours a day
So now I’m getting close to averaging 70 hours of focused iOS dev a week and it feels great. In a normal work place, “time spent working” != “productivity”, but for me they’re very similar as long as my energy is good, which it almost always is now.
The surprising insight is that changing the way that I measured my work performance–from spreadsheet, to better spreadsheet, to graph, to better graph–has had such a huge impact. I have been working on maximizing work productivity for four years, ever since starting the startup, but in the last six months I’ve become radically more effective. I love the percentile feedback graph design!

You can see his implementation on his homepage.

Percentile Feedback Update

In March I discovered that looking at a graph of my productivity (for the current day, with a percentile attached) was a big help. My “efficiency” — the time spent working that day divided by the time available to work — jumped as soon as the new feedback started (as this graph shows). The percentile score, which I can get at any moment during the day, indicates how my current efficiency score ranks according to scores from previous days within one hour of the same time. For example, a score of 50 at 1 p.m. means that half of the previous days’ scores from noon to 2 p.m. were better, half worse. The time available to work starts when I get up. For example, if I got up at 4 a.m., at 6 a.m. there were 2 hours available to work. The measurement period usually stops at dinner time or in the early evening.

This graph shows the results so far. It shows efficiency scores at the end of each day. (Now and then I take a day off.) One interesting fact is I’ve kept doing it. The data collection isn’t automated; I shift to R to collect it, typing “work.start” or “work.stop” or “work.switch” when I start, stop, or switch tasks. This is the third or fourth time I’ve tried some sort of work tracking system and the first time I have persisted this long. Another interesting fact is the slow improvement, shown by the positive slopes of the fitted lines. Apparently I am slowly developing better work habits.

The behavioral engineering is more complicated than you might think. My daily activities naturally divide into three categories: 1. things I want to do but have to push myself to do. This helps with that, obviously. 2. things I don’t want to do a lot of but have to push myself away from (e.g., web surfing). 3. things I want to do and have no trouble doing. But the recording system is binary. What do I do with activities in the third category? Eventually I decided to put the short-duration examples (e.g., standing on one foot, lasts 10 minutes) in the first category (counts as work), keeping the long-duration examples (e.g., walking, might last one hour) in the second category (doesn’t count as work).

Before I started this I thought of a dozen reasons why it wouldn’t work, but it has. In line with my belief that it is better to do than to think.

Percentile Feedback Workspace Available

I have put a requested R workspace on my website so that you can download it. The percentile feedback workspace compares your productivity (time spent working/time available to work) today to previous days. When I started using it, I became more productive. Here is an introduction. Here are all posts about it.

This is not for everyone. You need R installed to use it (of course) and you’ll need to know at least a little R. You must edit a function called so that the workspace is saved in the right place. I have used it under Windows XP.

Percentile Feedback and Productivity

Warning: This post, written for the Quantified Self blog, has more repetition than usual of material in earlier posts.

In January, after talking with Matthew Cornell, I decided to measure my work habits. I typically work for a while (10-100 minutes), take a break (10-100 minutes), resume work, take another break, and so on. The breaks had many functions: lunch, dinner, walk, exercise, nap. I wanted to do experiments related to quasi-reinforcement.

I wrote R programs to record when I worked.  They provided simple feedback, including how much I had worked that day (e.g., “121 minutes worked so far”) and how long the current bout of work had lasted (e.g., “20 minutes of email” — meaning the current bout of work, which was answering email , had so far lasted 20 minutes).

I collected data for two months before I wrote programs to graph the data. The first display I made (example above) showed efficiency (time spent working/time available to work) as a function of time of day. Available time started when I woke up. If I woke up at 5 am, and by 10 am had worked 3 hours, the efficiency at 10 am would be 60%. The display showed the current day as a line and previous days as points. During the day the line got longer and longer.

The blue and red points are from before the display started; the green and black points are from after the display started. The red and black points are the final points of their days — they sum up the days. A week or so after I made the display I added the big number in the upper-right corner (in the example, 65). It gives the percentile of the current efficiency compared to all the efficiency measurements within one hour of the time of day (e.g., if it is 2 p.m., the current efficiency is compared to efficiency measurements between 1 p.m. and 3 p.m. on previous days).

I started looking at the progress display often. To my great surprise, it helped a lot. It made me more efficient. You can see this in the example above because most of the green points (after the display started) are above most of the blue points (before the display). You can also see the improvement in the graph below, which shows the final efficiency of each day.

My efficiency jumped up when the display started.

Why did the display help? I call it percentile feedback because that name sums up a big reason I think it helped. The number in the corner makes the percentile explicit but simply seeing where the end of the line falls relative to the points gives an indication of the percentile. I think the graphical display helped for four reasons:

1. All improvement rewarded, no matter how small or from what level. Whenever I worked, the line went up and the percentile score improved. Many feedback schemes reward only a small range of changes of behavior. For example, suppose the feedback scheme is A+, A, A-, etc. If you go from low B- to high B-, your grade won’t change. A score of 100 was nearly impossible, so there was almost always room for improvement.

2. Overall performance judged. I could compare my percentile score to my score earlier in the day (e.g., 1 pm versus 10 am) but the score itself was a comparison to all previous days, in the sense that a score above 50 meant I was doing better than average. Thus there were two sources of reward: (a) doing better than a few hours ago and (b) doing better than previous days.

3. Attractive. I liked looking at the graphs, partly due to graphic design.

4.  Likeable. You pay more attention to someone you like than someone you don’t like. The displays were curiously likable. They usually praised me, in the sense that the percentile score was usually well above 50. Except early in morning, they were calm, in the sense that they did not change quickly. If the score was 80 and I took a 2-hour break, the score might go down to 70 — still good. And, as I said earlier, every improvement was noticed and rewarded — and every non-improvement was also gently noted. It was as if the display cared.

Now that I’ve seen how helpful and pleasant feedback can be, I miss similar feedback in other areas of life. When I’m walking/running on my treadmill, I want percentile feedback comparing this workout to previous ones. When I’m studying Chinese, I want some sort of gentle comparison to the past.






Efficiency Measurement Update

Here is another example of the efficiency graphs I’ve blogged about (here, here and here). The line is the current day; it shows how well I’m doing compared to previous days. It goes up when I work, down during breaks. The number in the right corner (“77”) is the percentile of my current efficiency (at the time the graph is made) compared to measurements within one hour (e.g., a measurement at 2 pm is compared to previous measurements between 1 pm and 3 pm).

The blue points come from before I started the feedback; the green points, afterwards. The red and black points are the final points of a day (that is, at quitting time). That the green points are above the blue points suggests that the graphical feedback helped. Here is a better way of seeing the effect of the feedback.

I didn’t expect this, as I’ve said. It is not “the effect of feedback”; before the graphical feedback, I’d gotten non-graphical feedback. It is a comparison of two kinds of feedback.

Why was the new feedback better? Here’s my best guess. It helped a little that it was pretty (compared to text). It helped a lot that it was in percentile form (today’s score compared to previous scores). This meant the score was almost never bad (from the beginning the percentile was was usually more than 50) and yet could always be detectably improved (e.g., from 68 to 70) with a little effort. I wish I could get such continuous percentile feedback in other areas of life – e.g., while treadmill running. I think feedback works poorly when it is discouraging or unpleasant and when it is too hard to improve. When I taught a freshman seminar at Berkeley, I got feedback (designed by a psychology professor) that was so unpleasant I stopped teaching freshman seminars. Because it came only at the end of the term, it was hard to improve — you’d have to teach the class again to get a better score. Moreover, it compared your score to everyone else’s.  I think I was in the lower 50%, which I found really unpleasant. There was no easy way to give feedback about the feedback; maybe it is still in use.

In contrast, I love the feedback shown in the upper graph. Not only does it really help, as the lower graph shows, it leaves me at the end of the day with a feeling of accomplishment.

Effect of Graphical Feedback on Productivity: Another Look

A few months ago, inspired by talking to added graphical feedback like this:

2011-04-01 work efficiency

The graph shows efficiency (time spent working/time available to work) versus time of day. The line shows the current day (not today, the current day when I made this graph). The higher the line, the better. When I work it goes up; when I take a break it goes down. The points are previous days. When the line is higher than the points, I am doing better than previous days. As I said in my first post, this seemed to help a lot: compare the green points (after graphical feedback) to the blue points (before graphical feedback). I blogged about possible explanations.

efficiency versus day

Here is more analysis. This graph shows efficiency versus day. Each point is the final efficiency (the efficiency after my last bout of work that day) for one day (the black and red points on the previous graph). These results suggest that the graphical feedback caused a sudden improvement, supporting the impression given by the blue/green (before/after) comparison of the earlier graph.

Before graphical feedback, the graph shows, efficiency was slowly increasing. Perhaps that was due to measuring when I was working, but I suspect it was due to the text feedback I got. I often used my tracking system to find out how long my current bout of work had lasted and how much I had worked so far that day. (For example, right now the text feedback is “15 minutes of blog, 73 minutes today”, which means I’ve spent 15 minutes writing this blog and before that worked 58 minutes on something else.)

Let me repeat what I said in another post: This was a big surprise. I collected this data for other reasons, which had nothing to do with graphical feedback. Before this project, I had made many thousands measurements of work time, but they were (a) tied to writing, not all work and (b) recorded inside the program I use for writing (Action Outline). Using R would have been slightly harder — that’s why I used Action Outline. I never studied the data, but I had the impression it helped.

You may know about the brain-damage patient H.M. His brain damage caused loss of long-term memory formation. He could remember something for a few minutes but not longer. The researcher working with him had to keep introducing herself. A pleasant side effect was that he could read the same thing again and again — a magazine article, for example — and enjoy it each time. This is like that. I am stupid enough that the results of my self-experimentation continue to surprise me (which I enjoy). You might think after many surprises I would stop being surprised — I would adjust my expectations — but somehow that doesn’t happen.

Why Did Graphical Feedback Improve My Work Habits?

A few days ago I posted about the effect of efficiency graphs — graphs of time spent working/available time vs time of day  (see below for an example). I used these graphs as feedback. They made it easy to see how my current efficiency compared to past days. As soon as I started looking at them (many times/day), my efficiency increased from about 25% to about 40%. I was surprised, you could even say shocked.  Sure, I wanted to be more efficient but I had collected the data to test a quite different idea. In this post I will speculate about why the efficiency graphs helped. Continue reading “Why Did Graphical Feedback Improve My Work Habits?”