## 2 Materials and Methods
### Product of Comparative Experiments
#### 2.2.2 Implementation of the Experiment  
Immediate and delayed examinations were conducted to evaluate the effects of immediate memory and delayed memory. The National Aeronautics and Space Administration Task Load Index (NASA-TLX) cognitive load scale and teaching satisfaction evaluation were used to evaluate the experience. The NASA-TLX is a widely used subjective multidimensional assessment tool. The NASA-TLX scale includes six indicators of physical exertion, brain power consumption, teaching rhythm, performance satisfaction, degree of effort and frustration. Finally, a satisfaction test and interview was conducted with the experimenter to directly obtain the ideas of VR teaching stakeholders and to evaluate the application effect of VR in construction teaching. This study refers to the moderately difficult waterproof engineering teaching content and selects the theoretical and practical knowledge of coiled waterproof roofing as a teaching case. Through group comparison experiments, questionnaires and interviews were conducted again to analyze the impact of virtual reality teaching on immediate and delayed memory effects, along with the cognitive load and experience of students in the teaching process. Table 1 shows the questions explored in this paper. After the traditional teaching and VR teaching, the two groups of students were asked to complete the questionnaire test within 10 min. The questionnaire test has a setup of 10 questions, including seven single-choice questions and three fill-in-the-blank questions, each of which is 1 point. The first six questions refer to the process steps of using the hot-melt method for the construction of coiled waterproof roofing, the direction of the overlapping direction of the coil, the angle and other memories of the process principle and sequence. The seventh question examines the student's observation of the construction details with the worker's helmet. The last three questions are based on the hot-melt method of laying of waterproof rolls to explore the differences in the students' ability to understand pictures under different teaching methods. According to the famous Ebbinghaus Forgetting Curve [30], after the learner's brain receives new things, the speed of forgetting gradually changing from fast to slow. After more than 2 days, the memory retention rate of the original new things will be less than 30%. To explore the difference in the effect of the two teaching methods on delayed learning, the 50 students were given a questionnaire again two days after the initial experiment with the same test content as the initial experiment. The cognitive experience assessment aims to explore whether the introduction of emerging technology equipment in construction teaching will interfere with the student learning experience and whether it can bring a more positive learning experience. After the completion of the initial experimental teaching task, both groups of students will have a satisfaction questionnaire survey on learning cognitive experience. The satisfaction questionnaire about learning experience uses the NASA-TLX to evaluate the load experience brought by the two teaching methods. The NASA-TLX experiment immediately collected the cognitive load level of the two groups on the six indicators after the initial experiment. The index of each indicator in the NASA-TLX scale ranges from 0 to 20 points, and every 2 points is divided into one class unit. A score of 0 indicates that the indicator load is extremely low, and a score of 20 indicates that the indicator load is extremely high. Teaching satisfaction evaluation is he students' evaluation of the course after education. First of all, the two groups of students evaluated the corresponding teaching methods by questionnaire survey after the subjective scoring of various cognitive load indicators. Based