1. 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

2. 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

3. Timescale of UI Evolution  1940s: Scientific instruments

4. 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

5. Timescale of UI Evolution  1940s: Scientific instruments  1950s: Mathematical tools  1960s: Data files & records

6. Timescale of UI Evolution  1940s: Scientific instruments  1950s: Mathematical tools  1960s: Data files & records  1970s: Command languages OBEY YES SIR

7. Timescale of UI Evolution  1940s: Scientific instruments  1950s: Mathematical tools  1960s: Data files & records  1970s: Command languages  1980s: Bitmapped screens, direct manipulation

8. “Modern” UI Essentials  Drawing e.g. Sketchpad 1963

9. “Modern” UI Essentials  Drawing e.g. Sketchpad 1963  Presentation e.g. NLS 1968 (also hypertext, online collaboration …)

10. “Modern” UI Essentials  Drawing e.g. Sketchpad 1963  Presentation e.g. NLS 1968 (also hypertext, online collaboration …)  Word Processing e.g. Bravo 1973-77

11. 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

12. 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

13. 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)

14. 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

15. 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.

16. 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

17. 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)

18. 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)

19. 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

20. 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

21. 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

22. 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?

23. 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

24. 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

25. 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

26. 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!)