In the present article, Constructive Approach is introduced for students, to model a simulation and develop a real system for VoIP. The main aim is to provide experiences on modeling and development of the real system with the equipment in the controlled laboratory environment by using established good laboratory and manufacturing practice. Developing systems, assigned to students, helped them to integrate their theoretical knowledge with their practical skills. Since classical courses are limited to the related theoretical knowledge given by an instructor, students can gain valuable experiences with fully developed functional simulation and the real system, important correlations and procedures, which are implemented in the engineering practice, and thus are introduced in this paper. ß

Due to the data of the Ministry of Justice of the Republic of Serbia, over 70% of persons being in prisons and serving their sentences are drug addicts, and 50% of them are drug users. In the European prisons, the percentage of persons using drugs in the entire prison population is 20-70%, and in the USA 70-80%, in the Australian prisons between 50 and 80% of the convicts in prisons are addicts of psychologically active substances. The results of our survey are pursuant to official statistics data for Serbia, the European countries, USA and Australia, since 80% of our convicts in prisons have misused psychologically active substances during the period of 30 days, the previous period before coming to these institutions. More than a half of our examinees (60%), misuses narcotics and alcohol occasionally or permanently, the alcohol users only 12.7%, and only narcotics 7.3% of the ones, meaning that a treatment of addiction disease should have a significant role in prevention of recidivism.

Evaluation is of a high importance in any format that has become widely present in educational process, at any level, starting from primary school education and finishing with higher institutional one. In the paper, it has been discussed on the Kirkpatrick's model of evaluation being applied under Covid-19 conditions, the condition that has never been present in the entire world before. It has been described and discussed the evaluation process under these circumstances and what is the satisfaction level of both students and tutors in it, and also all changes occurred during this pandemic. The discussion part of the paper has been researched in its several segments, where both pros and cons have been presented, where the focus is in the virtual classroom activities since the pandemic conditions. The examined sample has included both tutors and students at a university level, where the real outcomes of this process are seen through a prism of the main hypothesis of the paper and it is to examine why the evaluation process is also of importance to be present under Covid-19 conditions. A new element has also been discussed and applied here and it is related to time experience of both students and tutors and how they have perceived it in this virtual learning environment.