Latency Reduction

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Principle: Wherever possible, use multi-threading to push latency into the background

Latency can often be hidden from users through multi-tasking techniques, letting them continue with their work while transmission and computation take place in the background. Modern web browsers can pre-fetch data, reducing the dead time when the user reaches the end of a task and must wait for the next page to appear.

Principle: Reduce the user’s experience of latency

1. Acknowledge all button clicks by visual or aural feedback within 50 milliseconds
2. Trap multiple clicks of the same button or object.

Because the Internet is slow, people tend to press the same button repeatedly, causing things to be even slower.

Principle: Keep users informed when they face delay

Chart of Delay Feedback Times & Indicators

Principle: Make it faster to begin with

Eliminate any element of the application that is not helping. Be ruthless.

The sluggish speed of the early web set users’s expectations extremely low. (It also burst the Internet bubble when people realized they could get in their car and drive round-trip to the shopping center in less time than it took to “trick” the website into selling them something.) They have become less forgiving as time has passed.

Mobile, which has an architecture more in keeping with traditional GUI applications than web browsing, has been reminding people that computers can be fast, and they are even more impatient with slow-downs. Wearables will come with an even higher level of expectation: No one waits to see what time it is, and they will not wait to see who is calling, what the temperature is outside, or any other information to be displayed.

Automotive applications today are oftentimes sluggish, suffering from a fatal cocktail of weak hardware, poor design/coding practices, and high latency. Consider the car hurtling down the road at 88 feet per second (27 meters per second) while the user, eyes fixed on the flat panel display, waits to learn which of ACDC’s many fine works he’s currently enjoying. Imagine the rich irony when the accident report reveals it was “Highway to Hell.”