Pictorial and Verbal Representation of Route Information

1. Pictorial and Verbal Representation ofRoute Information Paul Lee & Barbara Tversky Stanford University

2. “Picture is worth a thousand words.” • Underlying Assumptions • Depictions (e.g. diagrams, maps) fundamentally different than descriptions (e.g. texts, directions). • Depictions better than descriptions • But… • For certain tasks (e.g. route wayfinding), depictions and descriptions convey similar information.

3. Constraints by Depictive Medium Constraints by Descriptive Medium Common Structure Route Directions Sketch Maps Route Maps & Route Directions • Are the schematizations similar? • Ask students outside dorm how to get to Taco Bell

4. Sketch Map 1

5. Sketch Map 2

6. Directions 1 • From Roble parking lot • R onto Santa Theresa • L onto Lagunita (the first stop sign) • L onto Mayfield • R onto Bowdoin • L onto Stanford Ave • R onto El Camino • go down a few miles. It’s on the right.

7. Direction 2 Go down street toward main campus (where most of the buildings are as opposed to where the fields are) make a right on the first real street (not an entrance to a dorm or anything else). Then make a left on the 2nd street you come to. There should be some buildings on your right (Flo Mo) and a parking lot on your left. the street will make a sharp right. Stay on it. That puts you on Mayfield Rd. The first intersection after the turn will be at Campus Dr. Turn left and stay until you get to El Camino. Turn right (south) and Taco Bell is a few miles down on the right.

8. Segmentation according to Denis • Start point: “you leave the building” • Reorientation: “you turn left” • Path/progression: “you follow Main St.” • End point: “until you get to the restaurant”

9. Was all necessary information included? • Maps: Yes • Directions: No, incomplete explicitly • 75% lacked start or end point • 45% lacked path/progression information • Missing information recovered by 2 rules: • Continuity • Forward progression

10. Was extra information included? • Yes, in 90% of maps and directions • Added information kept traveler on track: • cardinal directions • arrows • distances • extra landmarks

11. Path Types: Text vs. Depiction

12. Goodness Ratings • 23 Subjects rated the goodness of the maps and directions • 1-7 rating scale: 1=not usable; 7=excellent

13. Good Map 1 (rating = 5.73)

14. Good Map 2 (rating = 5.50)

15. Avg. Map 1 (rating = 3.73)

16. Avg. Map 2 (rating = 3.68)

17. Bad Map 1 (rating = 2.68)

18. Bad Map 2 (rating = 2.23)

19. Good Direction (5.59) • From Roble fields head out towards campus • at Campus drive turn right • follow Campus around until you hit palm drive • turn left onto palm drive • go on palm until you hit el camino • turn rt. Onto el camino (it’s one of those things where you merge right) • head south on el camino • pass several lights (~2.3) • Taco Bell will be on your right, on the corner of some street & el camino

20. Average Direction (3.73) • Go out St. Theresa • turn Rt. • Follow Campus Dr. way around to Galvez • turn left on Galvez • turn right on El Camino • Go till you see Taco Bell on your right

21. Bad Direction (2.68) • Lomita • Mayfield --> Row Houses • Left onto Campus Drive East • Follow to SERRA • rt. on SERRA • rt. onto EL CAMINO - 2 miles down EL CAMINO

22. How was information schematized? • Start/end points: landmarks, paths • Maps: icons, rough shapes, street names • Directions: names, descriptions • Reorientations: amount unspecified • Maps: roughly perpendicular lines, arrows • Directions: “turn,” “take a,” “make a,” “go” • Path/progression • Maps: straight or curved line • Directions: “go” or “follow”

23. Depictive Toolkit • Intersections • Straight Paths • Curved Paths • Landmarks • Arrows

24. Descriptive Toolkit • Start at A facing B • Turn R/L, turn R/L on (x) • Go down (x), go down (x) until, go down (x) for (y) • Follow, follow until (x), follow (x) for (y) • Continue past • Z will be on your L/R

25. Toolkit Map 1

26. Toolkit Map 2

27. Toolkit Map 3

28. Toolkit Map 4

29. Toolkit Map 5

30. Toolkit Direction 1 • Start at Cowell, facing Campus Loop. • Turn right on Campus loop and follow until Serra St. • Turn right on Serra St. • Turn left on El Camino Real. • Go down El Camino Real and Town & Country will be on your right.

31. Toolkit Direction 2 • Start at Cowell Health Center, facing Campus drive loop. • Turn right at Campus Drive. • Follow Campus Drive until the first stop sign. • Turn right on Bowdoin. • Follow Bowdoin until the second stop sign. • Turn left on Stanford Avenue. • Go down Stanford Avenue, past 2 lights and a stop sign, until you reach the third light (El Camino real) • Turn left on El Camino. • Follow El Camino (northwest)past 2 stop lights for about one mile until you reach Embarcadero. (there is a light there) • Turn right immediately after the light at Embarcadero into the T & C Plaza.

32. Results: Depictive Toolkit • Intersections • Use of wrong X, L, T intersection - 93% of participants • Most cases: X -> T and T -> L • Non-prototypical intersection - 43% • Exit ramps - 57% • Paths • Used only straight paths (i.e. no curved paths) - 14% • Non-prototypical paths - 29%

33. Results: Depictive Toolkit • Landmarks • Added by participants • Stop signs/lights - 43% • Overpass - 43% • Iconic landmarks - 21% • Arrows - 86% • Additional Information • Cardinal direction - 14% • Distance information - 7% • Commentary - 50%

34. Results: Descriptive Toolkit • Turns • Alternative wording (e.g. “make/take a”) - 21%of participants • “exit at ___” - 43% • Specified turn angles - 50% • Progressions • Alternative wording (e.g. take, head down, stay on, pass, proceed, get on) - 14% • Path description - 57%

35. Results: Descriptive Toolkit • Landmarks • Stop signs/lights - 86% of participants • Overpass - 7% • Dead end - 21% • Parking lot - 14% • Additional Information • Time/distance information - 71% • Commentary - 29%

36. Mega-descriptions/depictions • Denis: ideal skeletal descriptions derived from mega-descriptions • Experiment Task • Subjects receive “mega-descriptions” or “mega-depictions” of the route • 12 cross streets and 44 landmarks included • Subjects are asked to cross out phrases or landmarks to create an ideal description or depiction • Skeletal description/depiction created from retention of phrases and landmarks by 70% of subjects

37. Skeletal Depiction

38. Skeletal Description Directions You are standing on Santa Teresa St. Take Santa Teresa down. Turn right on Lomita. Turn left on Mayfield. Take Mayfield until the road stops at a stop sign and veer right, in front of Xanadu. Follow the road to the right. At a 4-way stop junction, turn left on Campus Dr. East. You will come across a 4-way stop junction in front of a gas station. Turn right on Serra. Turn left on El Camino Real and continue for about 2-3 miles. Once you pass Curtner St, start looking for Taco Bell on the right.

39. Retained Landmark Types

40. Summary • Similar schematizations for route maps and route directions • Can determine “goodness” of maps and directions • Majority of route information can be expressed with a small finite set of depictions and descriptions