LIST OF TABLES

2.1           Example of VRML code

3.1           Complete factorial design of experiment

3.2           Characteristics of cylinders within each world

4.1           Descriptive statistics of participant estimates, 30 per group

4.2           Summary of standardized estimates for 30 participants

4.3           Descriptive statistics of standardized estimates

4.4           Results of multiple analysis of variance

4.5           Descriptive statistics for main effects

4.6           Post-hoc tests of user interaction levels

4.7           Descriptive statistics for two-factor interactions

4.8           Descriptive statistics for three-factor interactions

4.9           Number of participant movements within participant controlled worlds

4.10       Total estimates made at pre-set viewpoints in participant controlled worlds

4.11       Mean and maximum number of participant estimates made at pre-set viewpoints

4.12       Mean and maximum number of pre-set and participant created viewpoints used by participants to make estimates within one world

4.13       Spearman Rank Correlation for accuracy of participant estimates compared with total time required to conduct experiment

4.14       Results of unpaired t-test on groups of time (< 30 minutes, > 30 minutes) required for participants to complete experiment

4.15       Time in minutes between first and last estimates in each world among 30 participants

4.16       Wilcoxon signed rank test results comparing three user interaction levels by map type (flat vs. 3D terrain)

4.17       Results of ANOVA on time spent making estimates by user interaction level

4.18       Results of post-hoc tests on time spent making estimates by user interaction level

D.1     Estimates by 30 participants of cylinder height in flat map world, static view, sorted by actual height and cylinder state (rotating or stationary)

D.2     Estimates by 30 participants of cylinder height in flat map world, pre-programmed fly-by, sorted by actual height and cylinder state (rotating or stationary)

D.3     Estimates by 30 participants of cylinder height in flat map world, participant controlled, sorted by actual height and cylinder state (rotating or stationary)

D.4     Estimates by 30 participants of cylinder height in 3D terrain map world, static view, sorted by actual height and cylinder state (rotating or stationary)

D.5     Estimates by 30 participants of cylinder height in 3D terrain map world, pre- programmed fly-by, sorted by actual height and cylinder state (rotating or stationary)

D.6     Estimates by 30 participants of cylinder height in 3D terrain map world, participant controlled, sorted by actual height and cylinder state (rotating or stationary)

F        Time in minutes between making the first and last estimate within each world, followed by the total time from Start to Finish

LIST OF FIGURES

1.1        Basic population map of Hawai`i (Juvik and Juvik 1988)

2.1        Example of VRML world

3.1        Picture of map used in experiment

3.2        Map as presented in VRML with toolbars on left and bottom of screen; flat map on top, 3D terrain map on bottom

3.3        VRML world as used in the experiment showing cylinders placed atop the map

3.4        Cortona VRML Client navigation tool bars showing buttons used in experiment

3.5        Data entry window for experiment

3.6        View of screen in experiment with flat map in static view world before data entr

4.1        Graphical distribution showing overall relative frequency of all participant estimates (1800) of population represented by cylinder height

4.2        Line plot of map type with 95% confidence interval bars

4.3        Line plot of user interaction with 95% confidence interval bars

4.4        Interaction between map type and user interaction with 95% confidence interval bars

4.5        Interaction between cylinder state and map type with 95% confidence interval bars

4.6        Interaction between cylinder height and user interaction with 95% confidence interval bars

4.7        Interaction between cylinder height, cylinder state and user interaction with 95% confidence interval bars

4.8        Average accuracy of estimates plotted against total time to complete experiment

4.9        Interaction by map type between user interaction levels with 95% confidence interval bars

C.1   View of flat world, static view

C.2   View of flat world, pre-programmed fly-by (while rotating)

C.3   View of flat world, participant controlled

C.4   View of 3D terrain world, static view

C.5   View of 3D terrain world, pre-programmed fly-by (while rotating)

C.6   View of 3D terrain world, participant controlled

E       Graphical distribution of participant estimates by map type, user interaction and cylinder state