[ExI] ai class at stanford

[BillK]

On Wed, Aug 24, 2011 at 2:41 PM, Kelly Anderson wrote:
> What we really need for spreadsheets to more fully reach their full
> potential are:
> 1) Hosted in the cloud (ala Google Spreadsheets)
> 2) Ability to reference values from other spreadsheets with live
> updates (Hyper-references)
> 3) Ability to access data from anywhere inside the spreadsheet. (HTTP,
> web services, etc.)
> 4) Ability to send notices from Excel to other environments. (email,
> sms, web services, etc.)
>
> Give me that and I'll be all over programming in Excel.
>
>


Yes, very nice, except for the elephant in the room.

Generally it is estimated that programming in spreadsheets has about
the same error rate as normal programming. i.e. pretty high. But where
a program breaks, a spreadsheet still offers you neat rows and columns
of figures. So most spreadsheets don't get a thorough debugging.

<http://www.strategy-at-risk.com/2009/03/03/the-risk-of-spreadsheet-errors/>

Quote:
Audits done shows that nearly 90% of the spreadsheets contained
serious errors. Code inspection experiments also shows that even
experienced users have a hard time finding errors, succeeding in only
finding 54% on average.

Powell et alii settled for six error types:

   1. Hard-coding in a formula – one or more numbers appear in
formulas         75%
   2. Reference error – a formula contains one or more incorrect
references to other cells 11%
   3. Logic error – a formula is used incorrectly, leading to an
incorrect result    8%
   4. Copy/Paste error – a formula is wrong due to inaccurate use of copy/paste
   5. Omission error – a formula is wrong because one or more of its
input cells is blank
   6. Data input error – an incorrect data input is used
-------------------


BillK