Explorable Explanations
Explorable Explanations
Bret Victor / March 10, 2011
postscript, February 2024
What does it mean to be an active reader ?
An active reader asks questions, considers alternatives, questions assumptions, and even questions the trustworthiness of the author. An active reader tries to generalize specific examples, and devise specific examples for generalities. An active reader doesn't passively sponge up information, but uses the author's argument as a springboard for critical thought and deep understanding.
Do our reading environments encourage active reading? Or do they utterly oppose it? A typical reading tool, such as a book or website, displays the author's argument, and nothing else. The reader's line of thought remains internal and invisible, vague and speculative. We form questions, but can't answer them. We consider alternatives, but can't explore them. We question assumptions, but can't verify them. And so, in the end, we blindly trust, or blindly don't, and we miss the deep understanding that comes from dialogue and exploration.
Explorable Explanations is my umbrella project for ideas that enable and encourage truly active reading. The goal is to change people's relationship with text. People currently think of text as information to be consumed. I want text to be used as an environment to think in.
This essay presents examples of a few initial ideas:
A reactive document allows the reader to play with the author's assumptions and analyses, and see the consquences.
An explorable example makes the abstract<br>concrete, and allows the reader to develop an intuition for how a system works.
Contextual information allows the reader to learn related material just-in-time, and cross-check the author's claims.
As always, if any of this inspires you to play around with these concepts, I'd love to see what you come up with.
1. Reactive Documents
Ten Brighter Ideas was my early prototype of a reactive document . The reader can play with the premise and assumptions of various claims, and see the consequences update immediately. It's like a spreadsheet without the spreadsheet. Give it a try.
Here is a more simplistic example of the same concept.
This propopsition was real, but the analysis is made up for this example, and is probably wildly<br>inaccurate.
Proposition 21: Vehicle License Fee for State Parks
The way it is now:
California has state parks, including state beaches and historic parks.<br>The current $ million budget is insufficient to maintain these parks,<br>and parks will be shut down at least part-time.<br>Most parks charge per vehicle for admission.
What Prop 21 would do:
Proposes to charge car owners an extra $18 on their annual registration bill, to go into the state park fund. Cars that pay the charge would have free park admission.
Analysis:
Suppose that an extra<br>was charged to<br>% of<br>vehicle registrationsCalifornia taxpayers.<br>Park admission would be for<br>everyonethose who paid the charge.
This would collect an extralose<br>$ million<br>($ million from the tax,<br>plusminus<br>$ million<br>additionallost revenue from admission)<br>for a total state park budget of $ million.
This is not sufficient to maintain the parks, and<br>parks would be shut down at least part-time.<br>This is sufficient to maintain the parks in their current state, but not fund<br>a program to bring safety and cleanliness up to acceptable standards.<br>This is sufficient to maintain the parks in their current state, plus fund a program to<br>bring safety and cleanliness up to acceptable standards over the next<br>years.<br>This is sufficient to maintain the parks and bring safety and cleanliness up to acceptable standards,<br>leaving a $ million per year surplus.
Park attendance would<br>risefall by<br>, to<br>million visits each year.
Is this a good proposition? It's hard to evaluate without context. The active reader might wonder, "Why $18? What if the tax were more or less?" Or, "Could park admission be raised instead?" If we were reading this on paper, such questions could only be answered by a phone call or heavy research.
Fortunately, this isn't paper. Some parts of the analysis above are underlined -- try adjusting them and see if you can answer those questions.
Notice how the consequences of your adjustments are reflected in the following paragraph. The reader can explore alternative scenarios, understand the tradeoffs involved, and come to a more confident conclusion about whether the proposition is a good decision.
Modeling
There's nothing new about scenario modeling. The authors of this proposition surely had an Excel spreadsheet which answered the same questions. But a spreadsheet is not an explanation. It is merely a dataset and model; it cannot be read. An explanation requires an author , to interpret the results of the model, and present them to the reader via language and graphics.
The reactive document integrates spreadsheet-like models into authored text. It can be read at multiple levels, depending on the reader's...