Transcript Why does the spreadsheet work … and how can we improve it? A

Why does the spreadsheet work …
… and how can we improve it?
A user interface perspective on the foundations
of spreadsheets.
Alan Blackwell
Computer Laboratory
Cambridge University
Outline
 Why the spreadsheet was invented
 Which features were critical to success
 HCI research in spreadsheet use
 Where next?
 Grounds for critique of current products
 Possible product futures
 Possible futures for spreadsheet users
Timescale of UI Evolution
 1940s:
Scientific instruments
Timescale of UI Evolution
 1940s:
Scientific
instruments
 1950s:
Mathematical
tools
DIMENSION A(11)
READ A
2
DO 3,8,11 J=1,11
3
I=11-J
Y=SQRT(ABS(A(I+1)))+5*A(I+1)**3
IF (400>=Y) 8,4
4
PRINT I,999.
GOTO 2
8
PRINT I,Y
11 STOP
Timescale of UI Evolution
 1940s:
Scientific
instruments
 1950s:
Mathematical tools
 1960s:
Data files &
records
Timescale of UI Evolution
 1940s:
Scientific instruments
 1950s:
Mathematical tools
 1960s:
Data files & records
 1970s:
Command languages
OBEY
YES
SIR
Timescale of UI Evolution
 1940s:
Scientific instruments
 1950s:
Mathematical tools
 1960s:
Data files & records
 1970s:
Command languages
 1980s:
Bitmapped screens,
direct manipulation
“Modern” UI Essentials
 Drawing
 e.g. Sketchpad
1963
“Modern” UI Essentials
 Drawing
 e.g. Sketchpad
1963
 Presentation
 e.g. NLS 1968
 (also hypertext,
online collaboration
…)
“Modern” UI Essentials
 Drawing
 e.g. Sketchpad
1963
 Presentation
 e.g. NLS 1968
 (also hypertext,
online collaboration
…)
 Word Processing
 e.g. Bravo 1973-77
Inventing the Spreadsheet (1978)
 Bricklin’s concept:
 “electronic
blackboard”
 closest to NLS
collaboration tools?
 Frankston’s
optimisation:
 fast, compact &
responsive
 Fylstra’s market:
 individual
ownership and
control via PCs
Outline
 Why the spreadsheet was invented
 Which features were critical to success
 HCI research in spreadsheet use
 Where next?
 Grounds for critique of current products
 Possible product futures
 Possible futures for spreadsheet users
From Apple II to IBM PC / MS-DOS
 PC Functionally equivalent to the Apple II
 (no mouse, no bitmapped display)
 Business software emphasis
 simple databases
 word processing
 Lotus 1-2-3 replaced VisiCalc, included
charts and plots (as well as some
database and text formatting)
Direct manipulation
 Original Mac applications were “creative”
 writing, drawing, painting
 derived from Kay’s vision of creative machine
 Business market developments
 desktop publishing created business market
 Apple asked Microsoft to develop a SS
 Excel
 offered direct manipulation benefits of the Mac
 point and click, menus, windows, prompts
The Spreadsheet “Metaphor”
 HCI textbooks propose metaphor as
starting point for UI design.
 But there is little evidence that the paper
SS ever influenced the development of
SS software.
 Most benefits historically derived from UI
features of other software categories.
Outline
 Why the spreadsheet was invented
 Which features were critical to success
 HCI research in spreadsheet use
 Where next?
 Grounds for critique of current products
 Possible product futures
 Possible futures for spreadsheet users
Experimental extensions
 UI builder functions (Myers)
 Navigation aids (Rao & Card)
 Debugging aids (Burnett et. al.)
 Typing and inference (Erwig)
 Gesture interfaces (Wolf, Burnett)
 Approximation, graphics (Lewis)
 Multi-user support (various)
 Tutoring and help systems (various)
 Voice interfaces (various)
Spreadsheets in end-user context
 Bonnie Nardi, A Small Matter of
Programming (MIT Press 1993) notes:
 SSs are immediately useful for real tasks
 SSs support direct manipulation
 SSs have limited control constructs
 SSs lead to collaborative communities
 But SSs are:
 Not automatically easy to learn (Hendry
& Green)
 Liable to contain errors (Panko, others)
Mental models of spreadsheets
 The user’s “mental model” is critical in HCI
 But hard to say what goes on inside a
programmer’s head!
 Saarilouma & Sajaniemi (1989) showed SS
users employ visual images
 Navarro Prieto (1998) found visual images
help SS users understood dataflow
 Petre & Blackwell (2000) note that many
programmers report experiencing images
Some theoretical design principles
 Cognitive Dimensions of Notations
 Discussion vocabulary for significant
design attributes and tradeoffs
 (see Green & Petre in JVLC 1996,
Blackwell & Green in Carroll, ed. 2003.)
 Surprise, Explain, Reward
 We’ve built it, but will they come?
 (see Robertson et. al., CHI 2004)
 See also Blackwell’s Attention
Investment theory of abstraction use
Outline
 Why the spreadsheet was invented
 Which features were critical to success
 HCI research in spreadsheet use
 Where next?
 Grounds for critique of current products
 Possible product futures
 Possible futures for spreadsheet users
Lessons from history & research
 Account for collaboration
 Be fast and responsive
 Empower individuals
 Provide a flat, imageable world
 Support direct manipulation
 Do current products retain these benefits?
Outline
 Why the spreadsheet was invented
 Which features were critical to success
 HCI research in spreadsheet use
 Where next?
 Grounds for critique of current products
 Possible product futures
 Possible futures for spreadsheet users
Features are not the answer
 Applications are developed in SSs because
of their low entry cost, seldom on
engineering grounds.
 57% of 5500 SSs had no formulas
 Can SS functions be partitioned into
developer and end-user sets?
 How would the transition be managed?
 Can we provide engineering benefits to end
users?
 EUSES, e.g. Burnett, Erwig, Blackwell
Outline
 Why the spreadsheet was invented
 Which features were critical to success
 HCI research in spreadsheet use
 Where next?
 Grounds for critique of current products
 Possible product futures
 Possible futures for spreadsheet users
User simplification
 If the SS has been moving away from its
roots, can users (or organisations) return?
 Templates
 Process definitions
 Reduced-feature standards
 Adapt open-source products
 Any more options? (DISCUSS!)