# Visual and Haptic Guidance for Enhancing Target Search Performance in Dual-Task Settings
## 3 Study 1: Visual Guidance Design and Evaluation
### Results
#### 3.2.2 Reaction Time, Selection Time, and User Behavior Data in Secondary Task of Study 1  
Reaction Time For the secondary task, we collected data on the participants' reaction times. Considering that the human central visual field typically spans a 60\({}^{\circ}\) diameter and is capable of detecting major contrasts, colors, and motion [62], and all the targets in Primary Task were located inside this area, we measured the reaction time of the Secondary Task from the instant that the arrow was displayed to the point when the participant's head movement exceeded a 30-degree angle from the forward direction. Main effects were found for Arrow Type \((F_{1,11}=16.03,p<0.01)\) and Column \((F_{4,44}=6.40,p<0.001)\). An interaction effect was found for Row \(\times\) Column \((F_{2,52,27.76}=5.59,p<0.01)\). (The sphericity assumption was not met so the Greenhouse-Geisser correction was applied; the corrected degrees of freedom are shown.) No other main effect or interaction effect was found. The mean reaction times across Arrow Type, Visual Guidance Continuity, Row, and Column are illustrated in Figure 3a. Post hoc Bonferroni pairwise comparisons showed that the reaction time for the Dynamic Arrow (4.66 s) was significantly faster than that for the Static Arrow (5.87 s) \((p<0.01)\), and column 5 (4.71 s) was significantly faster than column 3 (5.09 s). Selection Time For the Secondary Task, we recorded the selection time from the point when the participant's head movement exceeded a 30-degree angle from the forward direction to the point when a successful selection was made. Main effects were found for Arrow Type \((F_{1,11}=14.77,p<0.05)\) and Column \((F_{4,44}=6.73,p<0.001)\). No other main effect or interaction effect was found. The mean selection times across Arrow Type, Visual Guidance Continuity, Row, and Column are illustrated in Figure 3b. Post hoc Bonferroni pairwise comparisons showed that the reaction time for the Dynamic Arrow (3.32 s) was significantly faster than that for the Static Arrow (3.67 s) \((p<0.01)\), and column 2 (3.16 s) was significantly faster than column 3 (3.89 s). Head Rotation Angle We recorded the total head rotation angle during the selection time. Main effects were found for Arrow Type \((F_{1,11}=5.41,p<0.05)\) and Column \((F_{4,44}=8.94,p<0.001)\). No other main effect or interaction effect was found. The mean reaction times across Arrow Type, Visual Guidance Continuity, Row, and Column are illustrated in Figure 3c. Post hoc Bonferroni pairwise comparisons showed that the head rotation angle for the Dynamic Arrow (141.06 degrees) was significantly less than that for the Static Arrow (152.26 degrees) \((p<0.01)\), and column 2 (134.87 degrees), column 4 (145.41 degrees), and column 5 (140.71 degrees) were significantly less than column 3 (170.04 s). Head Movement Distance We recorded the total head movement distance during the selection time. A main effect was found for Column \((F_{1,98,21.78}=4.00,p<0.05)\), (The sphericity assumption was not met so the Greenhouse-Geisser correction was applied; the corrected degrees of freedom are shown.) No other main effect or interaction effect was found for the Modality and Row. Post hoc Bonferroni pairwise comparisons showed that the head movement distance of column 2 (23.59 cm) was significantly shorter than that for column 3 (28.04 cm) \((p<0.01)\). We also recorded the head movement distance along the X, Y, and Z dimensions. For the X dimension, a main effect was found for Column \((F_{2,30,25.30}=4.00,p<0.05)\). (The sphericity assumption was not met so the Greenhouse-Geisser correction was applied; the corrected degrees of freedom are shown.) No other main effect or interaction effect was found for the Modality and Row. Post hoc Bonferroni pairwise comparisons showed that the head movement distance along the X dimension of column 2 (13.71 cm) was significantly shorter than those of column 3 (16.96 cm) (\(p<0.01\)) and column 1 (15.12 cm) (\(p<0.05\)). For the Y dimension, a main effect was found for Column \((F_{4,44}=10.28,p<0.001)\).