# VIS-HAPT: A Methodology Proposal to Develop Visuo-Haptic Environments in Education 4.0
## 5 VIS-HAPT Methodology, Results and Discussion
### Comparative Study of the Times Used for Each Phase with and without VIS-HAPT Methodology  
#### 5.3.1 Reported Times without and with Methodology  
The times recorded (in hours) for the different phases--_with_ and _without_ applying the proposed methodology--were estimated from a weekly log in which the times employed in each stage by the developers and researchers were carefully recorded, as required by our institution. The recorded times for the different phases considered the following aspects:  
1. _Learning experience design._ The time dedicated in this phase includes: (a) the number of sessions and hours spent on selecting each educational scenario; (b) the time needed to design the contextualized physical phenomenon; (c) the time spent on the design of the visualization elements; and (d) the time invested in deriving the physical model needed to build the visuo-haptic environment;
2. _Definition of the technological model._ In this phase, we consider (a) the time taken to prepare the visuo-haptic design; (b) the time of the sessions dedicated to defining the visuo-haptic device and programming its connections to the environment; (c) the time invested to enable the haptic rendering; and (d) the time of the application programming. 3. _Calibration and testing._ The time recorded for this phase includes: (a) the time for planning and executing the tests with model students; (b) the time needed to recalibrate the models; and (c) the time spent in the planning, design, and application of the usability tests. 4. _Applications and field studies._ This phase includes (a) the recorded planning times for the implementation of the field studies with experimental and control groups; (b) the time needed for the design the activity guides given to the students during the learning experience; (c) the time needed design and administer the pre-test and post-test; (d) the time needed to design and administer the opinion surveys; and (e) the time taken to analyze the data and results to measure learning gains and size effects. The reported times for phases 1 and 4 were estimated using the hours registered in our session logs, considering the number of sessions held by our team working on task (during the learning experience design), as well as through the different moments needed to carry out the field studies of the visuo-haptic application with the students. On the other hand, the times reported in phases 2 and 3 were taken from [9] and were used here to compare the Chai3D + OpenGL framework with the HaDIU plugin for each visuo-haptic simulator (as can be seen in Table 1 below), along with phases 1 and 4 included in the present work. Figure 12: Interface elements of the plane charge visuo-haptic environment developed with VIS-HAPT and _HaDIU_ architecture. Tables 1 and 2 show the recorded times (in hours) for the different phases with and without applying the proposed methodology, respectively. Comparing the times in Tables 1 and 2, the methodology helped to substantially reduce these times in all four phases. The average times dedicated to developing and implementing the visuo-haptic environments for these phases were reduced by 42%, 69%, 26% and 27%, respectively, with an average reduction of 44% compared to the cases without methodology. Therefore, the obtained times with the VIS-HAPT methodology are significantly smaller than those obtained without following the phases of the methodology. It is important to recognize that this remarkable time decrement may also be in part due to the acquired knowledge of the visuo-haptic environments' technological models, as well as to the experience gained by the authors in the application and field studies phase. Our previous developments and publications (Section 3) were mainly focused on educational field studies to determine learning gains and student perception.