[ih] How long did it take?

[Dave Crocker]

On 9/17/2026 11:05 AM, Craig Partridge wrote:
> Over time, the reaction was what you'd expect: (a) customers pushed to 
> use premium dialup modems (the Trailblazer in the late 1980s could hit 
> 19.2Kbps); (b) dialup SLIP; and (c) leased lines.


In the very early days of doing "human factors " (now 'usability' or 
'user experience') research on subjects using the newfangled ability for 
multiple people to share the same computer at the same time, one of the 
things researched, as you might expect, was the effect of response time.

Many results were straightforward, and useful.  As I recall, three 
thresholds that were discovered were 200ms, 500ms and 2 seconds...

An unexpected result was to discover that users really hated variable 
response times.

They preferred a system that had a slower average response time, if it 
was more predictable/reliable, than one that had a significantly better 
average response time, but had much higher variability.

There might be some relationship between that and the preference Craig 
has cited.

d/

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Dave Crocker

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