Julie Heiser, Doantam Phan, Maneesh Agrawala, Barbara Tversky and Pat Hanrahan

1. Identification and Validation of Cognitive Design Principles for Automated Generation of Assembly Instructions Julie Heiser, Doantam Phan, Maneesh Agrawala, Barbara Tversky and Pat Hanrahan Stanford University and Microsoft Research

3. 1 2 3 4 5 6

4. Cognitive Design Principles • Identify • How people conceive of 3D assemblies • How people comprehend visual instructions • Validate • Build automated instruction design system • Evaluate usability of resulting instructions

5. Prior Work: Identification • Diagrams better for showing context • Diagrams and text equivalent for showing actions[Bieger 85] [Bieger 86] • High spatial  prefer diagrams only • Low spatial  prefer diagrams and text together[Winn 80] [Mayer 94] [Hegarty 94] [Kalyuga 98] [Trafton 2001] • Step-by-step better than showing only end state[Novick 00] • Arrows and lines convey actions and sequences[Tversky 00]

6. Prior Work: Validation • Automated presentation design systems • COMET[Feiner 89],IBIS[Seligmann 91], WIP[Andre 93], AWI[Rist 94], CATHI[Butz 97], [Strothotte 98], [Tang 03] CATHI IBIS AWI

7. Our Approach • Identification • Production • Preference • Comprehension • Validation • Instantiation • Usability

8. Our Approach • Identification • Production • Preference • Comprehension • Validation • Instantiation • Usability

9. Our Approach • Identification • Production • Preference • Comprehension • Validation • Instantiation • Usability

10. Our Approach • Identification • Production • Preference • Comprehension • Validation • Instantiation • Usability • Step-by-step, one diagram for each major step • Clear and explicit order • Parts added in each step should be visible • Mode of attachment should be visible

11. Our Approach • Identification • Production • Preference • Comprehension • Validation • Instantiation • Usability • Step-by-step, one diagram for each major step • Clear and explicit order • Parts added in each step should be visible • Mode of attachment should be visible

12. Our Approach • Identification • Production • Preference • Comprehension • Validation • Instantiation • Usability • Step-by-step, one diagram for each major step • Clear and explicit order • Parts added in each step should be visible • Mode of attachment should be visible

13. TV Stand • Contains several parts and actions • Ordering constraints • One person can assemble • Representative of other furniture

14. Spatial Ability Tests • Separate high and low spatial ability Mental Rotation[Vandenburg 78] Navigation[Money 78]

15. Stage 1: Production

16. Stage 1: Production • 43 Participants • Assemble TV Stand without instructions • Write instructions for novice assembler

17. Time to assemble (min) Low spatial High spatial Stage 1: Mean Completion Time 12.76 7.29

18. Stage 1: Instructions Produced • Almost all contained diagrams 98% • Text redundant with diagrams 62%

19. Stage 1: Errors in Instructions • Errors in low spatial instructions 86% • Errors in high spatial instructions 12%

20. Stage 1: Errors in Instructions • Errors in low spatial instructions 86% • Errors in high spatial instructions 12% support board sides

21. Stage 1: Classes of Diagrams • Parts menu to differentiate parts • Structural diagrams depict completed step • Action diagrams show assembly action/operation Structural diagrams Action diagrams Parts menu

22. Stage 1: Action Diagrams Mean number per set 2.67 0.64 Low spatial High spatial • High spatial • More action diagrams • More 3D diagrams • Less text

23. Stage 2: Preference

24. Stage 2: Preference • 21 Participants • Assemble TV Stand without instructions • Rated 39 sets of redrawn instructions

25. Stage 2: Highest Rated • Ratings similar across all participants • Spatial ability does not affect preference

26. Stage 3: Comprehension

27. Set 3: Parts menu + Structural + Action Stage 3: Comprehension • 44 Participants • Given 1 of 4 instruction sets from Stage 2 • Assemble TV stand using instructions Set 1: Text + Action

28. Stage 3: Results • No difference in assembly time by condition • Instruction consultations: Low 8.9 High 7.1 • Box picture consultations: Low 9.1 High 3.4 • Comments • Should show relevant parts and attachments • Structural diagrams and exploded view hard to use • Text not very useful

29. Cognitive Design Principles • Sequence assembly operations • Ensure visibility of parts • Illustrate assembly operations

30. Sequence Assembly Operations • Step-by-step, one diagram per major step • Clear and explicit order Single exploded view diagram Step-by-step diagrams

31. Ensure Visibility of Parts • Show parts added in each step • Show mode and location of attachment • Avoid changing viewpoint • Use physically stable orientation

32. Illustrate Assembly Operations • Use action diagrams rather than structural • Use arrows and guidelines to indicate attachment Structural diagrams Action diagrams

33. Stage 4: Instantiation

34. Stage 4: Instantiation[Agrawala et al. SIGGRAPH 03]

35. Structural Diagrams Action Diagrams All parts Search Leftover parts Best subset of parts Sequence Parts Reorientation Sequence of assembly steps

36. Stage 4: LEGO

37. Stage 4: Bookcase

38. Stage 5: Usability

39. Stage 5: Usability • 30 Participants • Given 1 of 3 instruction sets: hand-drawn, factory, computer • Assemble TV stand using instructions

40. Stage 5: Hand-drawn

41. Stage 5: Factory Produced

42. Stage 5: Computer Generated

43. Stage 5: Instructions Tested Hand-drawn Computer generated Factory

44. Stage 5: Results • Errors:Hand-drawn 1.6 Factory 0.6 Computer 0.5 • Users rated task as easiest in computer condition Time to assemble (min) 18.9 16.0 10.2 Hand-drawn Factory Computer

45. Summary and Conclusions • 5-Stage approach can give insight into effective design of assembly instructions • Cognitive design principles • Clear sequence of operations • Maintain good visibility • Use action diagrams • Extend approach beyond assembly instructions

46. Acknowledgements • Boris Yamrom • Christina Vincent • John Haymaker • Jeff Klingner

48. Generalization • Approach extends beyond assembly instructions Hand-drawn route map LineDrive route map [Agrawala 01]