Re: [lmi] InputSequence questions

[Greg Chicares]

On 2010-04-13 13:13Z, Vaclav Slavik wrote:
> 
> On Tue, 2010-04-06 at 12:40 +0000, Greg Chicares wrote:
[...]
>>  Let me suggest:
>> 
>>   show this     instead of this
>>   ---------     ---------------
>>    duration         year
>>     # years      for # years
> 
> It may be just me, but I find this terribly confusing, much more than
> "year" vs "# years". For me, "duration" *is* number of years [that
> something takes to finish]. Every time I have to deal with duration_mode
> and e_duration, I have to spend ten minutes rereading your explanatory
> mail again to grasp the meaning for long enough to write the code I
> need...

Jargon. If you pay a premium in the third through fifth durations,
inclusive, then you start paying in duration two and stop at duration
five, so:
  2 = begin_duration
  5 = end_duration
If you asked me the duration of premium payments, I wouldn't say
"three, because you pay for three years"; it wouldn't occur to me
that you meant 5 - 2. Instead, I might ask whether you meant the
beginning or ending duration, or I'd just say "two through four"
meaning [2,4] (though I'd be thinking [2,5) ).

> Of course, if no real user can be confused by this, then it's OK. Is
> "duration" domain-specific terminology that nobody but me will
> misunderstand?

Yes, exactly: it's life-insurance jargon. We might say that certain
policies become unprofitable in their later durations; or that the cost
of issuing them is recovered by the third duration, which would imply
that the cash value is low in the early durations. If your policy was
issued seven years ago, then we'd say you're in your seventh duration.

It's at least tenuously related to the dictionary meaning in that it's
an actual interval of time (implicitly beginning on the "issue date").
Things are worse in the financial world, where "duration" means the
first derivative of price wrt interest rate....

>> Alternatively, maybe it would be better to bring "until" out of static text
>> and into the combobox, for all selections except "for # years"; thus:
>> 
>>   [100] from issue date       [until age  ] [47], then
>>   [200] from age 47           [until year ] [ 5], then
>>   [300] from year 5           [for # years] [ 2], then
>>   [400] from year 5 + 2 years [until maturity]
>> 
>> Does that seem better?
> 
> I mentioned it before: this is clearly better readable, but it's worse
> for keyboard input, because you no longer can type just "a" to select
> "until age", you have to type "until a". Unless choice controls support
> accelerators in Windows, that is -- Vadim, do you know if they do?
> (There's no problem with intercepting "a" keystrokes and selecting
> "age", but unless there's a visual indicator such as menu
> accelerator-like underline, it's not discoverable and so pointless.)

Oh, I must have missed that.

Underlining anything in a combobox would strike me as extraordinary.
And even if there were underlines, we wouldn't see all the choices
unless we pulled it down.

> You can still use arrows to change the value using keyboard only, so
> yes, I think it would be better to include "until" in the control
> itself.

Yes, personally I always do alt-downarrow unless it's a really
long list and I'm sure what string I'm looking for--like typing
'U' in a country-code combobox to find "US". But by the time I've
hit alt-downarrow to see choices that I haven't memorized, my
fingers are on the arrow keys already, so I'd just use them.
Other people might do otherwise, of course, so beginning each
string with a unique letter has at least some value.

>>   from 2 years after retirement   | perfectly natural
>>   from 2 years after age 47       | good
>>   from 2 years after year 5       | strange
>> versus:
>>   from retirement + 2 years   | less natural, but perfectly clear
>>   from age 47 + 2 years       | okay
>>   from year 5 + 2 years       | a little weird
>> I'm not really sure whether one is better than the other.
> 
> I prefer the latter, with + in it. Not because it's shorter, but because
> that " + " area is a visual hint that lets you split the label into
> "base" and "offset" parts at a glance. I think that's something useful
> for understanding the sequence in its entirety, but maybe it doesn't
> matter.

Okay, good point.