What is Pile of Index Cards?
So-called "Index Cards" is 5 inch x 3 inch piece of paper. This old-fashioned index cards are getting popular.
 Return to analog world
Following two events became a breakthrough for a new era of index cards. Even though these two examples are quite conceptual, it is important to note they direct us to return to the analog world.
There are great books about productivity and index cards which written in 1960' to 1970' in Japan. The most famous index cards book in Japan is "知的生産の技術 (= A technique of intellectual productivity" (1969) by Tadao Umesao, the first director of National Museum of Ethnology. His use of index cards is not as a database, but more as a data warehouse.
West meets east. Do I have something more interesting with index cards in this digital age? PoIC is born to answer this question.
 Essence of the PoIC
Essence of the PoIC is represented in only three lines.
- Collect thoughts and information using index cards
- Store them in chronological order
- Reuse them later
The system and method I introduce in this manual does nothing but achieve these three lines.
 Key concepts behind
 Stress free
The chronological approach enables us to collect any individual idea/thought/information in a stress-free state. In fact, we will attempt to capture any idea. At a certain point, after enough cards accumulate, then we pick up cards from the box and attempt to reproduce new knowledge and accomplishments. Until the time comes, we need not think too much about classification and search that obviously become a bottleneck in personal productivity.
 Great habit of collection
David Allen frequently claims in his book "Getting Things DONE" (2002) about "great habit of collection". For example,
"You'll feel better collecting anything that you haven't collected yet." (p. 232)
"To fully realize that more productive place, you will need to capture it all." (p. 233)
"Doing the collection process as fully as you can, and then incorporating the behaviors of capturing all the new things as they emerge, will be empowering and productive." (p. 233)
PoIC is descended from philosophy of the GTD. PoIC's setup provide a possible solution to achieve David Allen's suggestions.
 Four type of information
Most of the people reading this manual probably know what GTD is and understand it. A philosophy of GTD is, in my understanding, to divide large projects into small tasks, and finish these tasks in a certain flow. After finishing the tasks, they are removed from the list, and long-term tasks are put into a Someday/Maybe list.
I think, however, all projects can not be expressed in terms of just a "task" (a check-box). Let's assume here is a personal project, "buy a new car", for example. The GTD covers tasks like "Get catalog" and "Go to exhibition". But it doesn't cover personal records and discoveries like "What color I want" or "What type" or "What is different between two cars". Knowing what I wants is a first step in the achievement of a project. So, I think these kind of information must be captured to "Getting Things DONE". To realize this, I will introduce Four Cards : Record, Discovery, GTD, and Cite.
 Two waves
The thoughts in a brains seem so random. It always happens that when I think one thing, something else with completely no connection pops up. For example, "what shall I eat for dinner tonight" kind of thinking emerges just after thinking about some difficult topic related to work. In the conscious level, one cannot think two things simultaneously. It will be an inconsistent act if one follow thoughts as they emerge.
At the same time, there is a certain long-term "order" behind such random thoughts. It implies that two kind of different waves are superimposed; short-term "random" wave and long-term "order" wave. I think tracking both waves is a key to improve my productivity. I have tried many ways to achieve this, whether digital or analog. In the end, analog index cards survived.
 The design of analog system
PoIC is a hybrid system that incorporates many ideas from five productivity books (Umesao, Kawakita, Watanabe, Itasaka, and Allen). The system will consists of a datawarehouse in mid- to long-term projects. The number of cards in the system grows day by day. It can exceed several hundred, several thousand easily.
 Keep it Simple!
Entropy in a natural system increases with time: This is the unavoidable property of nature. The point is, how I save effort in keeping system, and use remaining effort for true productivity. The possible solution is to make the system extremely simple. In this philosophy, I exclude many incompatible features, even though they work well for other systems, such as, Noguchi filing type revision rules, or Mac OS aliases.
I found I could improve my productivity even without these complicated features. Intellectual productivity is life long activity and not a boom explodes like a bubble. The best here is, "less is more" and "simple is best". I design this system stands for a year, decade or more. No battery, no computer, no printer required. What I need is pen, paper, and some simple technique. I have never seen simpler index cards system than PoIC.
 Make it fun!
When I start something I like, I cannot stop it easily. It is a key to connect this addictive vector to my productivity. One possible way is to make my system fun. I have been enjoying introducing new stationery in the system to make it fun. The stationery I show here is a result of my "trial and error". You will see many tips, tricks, and hacks throughout this manual. They are ways I make this system fun to use.
What is important is to enjoy yourself and keep writing. The stationery I introduce in this manual is not requirements, but recommendations. Especially, the size and type of cards and the color of pen are largely dependent on you. So you must use your favorites, though you should follow the PoIC's minimum rules, such as Four Cards and Chronological Order.
 Ideal of this manual
This manual is a records and result of an experiment for a question "What digital age can do with analog index cards?" So its "reproducibility" is taken greater importance in this manual. I describe in the following order; material, method, results, discussion, and references. You must go beyond the PoIC. There is a page "Your PoIC" at the last of this manual. You must contribute to fill this blank page with your idea.