Decisions involve tradeoffs. Time at work subtracts from time with your family; money saved for the future subtracts from goods and services now; many food choices trade off among taste, convenience, price, and nutrition.

Some tradeoffs in computer science are the cost to update versus the cost to search, and execution time versus memory consumption. Tradeoffs in software development include implementation time versus execution time, and compilation time versus object code quality. Tradeoff in project management include resource pool size versus communications overhead, and cost versus time versus quality. These tradeoffs are some of the tradeoffs, respectively, in such tasks as choosing a data structure, algorithm, or cache size; choosing a programming language, a compiler and compiler settings; and choosing a project team size and personnel.  read more »

Patrick Roberts has written a fascinating post on Responsive User Interfaces. It’s easy to make a specific application responsive, through careful coding and by limiting what the user can do. An architecture for doing this, with arbitrary functionality, is one of the holy grails of GUI frameworks. Patrick’s post is a step towards this.

Patrick defines responsive as “the UI never locks up and provides at least partial results ASAP, not that every operation is completed instantaneously”. His design uses a UI thread that runs performs fast operations, and pushes slow operations onto a queue. A background thread runs these operations in priority order.  read more »

Tucker asked me if there was a name for the phenomenon where someone you don’t know asks you to watch over their possessions. I’m asked to do this a few times a day, for anything from books to laptops, at the ERC. (At the yuppie establishments that I also frequent, I’m not asked at all.)

If you’re worried that a total stranger might steal your belongings, why is it safe to ask a total stranger to guard them? There are at least two reasons.  read more »

These are some hard questions my kids asked me when they were very young, with answers below:  read more »

• Why are far away things small?
• Why is it easier to pull a stroller (along a driveway with large gravel) than to push it?
• Why can we breath air but not dirt?

I’ve been reading about Col John Boyd’s OODA Loop —- Observe, Orient, Decide, and Act —- and I realized that some of the thinking based on this theory articulates intuitive reasons I’d had for liking zero defect milestones. Strategies such as “shortening your loop” and “getting inside” the enemy’s loop are those that zero defect milestones facilitate. If “Act” is the process of shipping a release, keeping the software in a shippable state preserves the ability of an organization to change the length of its loop based solely on external schedule requirements, without added constraints due to the accumulation of quality and other technical debts.  read more »

I’ve noticed that there’s two ways of giving directions to a location (say, when a driver pulls over to ask you how to get to a restaurant). Declarative directions specify where a location is relative to the current location; for example, “Two blocks ahead and across the street.” Procedural directions specify the steps that have to be taken to reach a location; for example, “Go straight three blocks, take a u-turn, go one block, and it’s the first building on your right.”
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