## 4 Experiment  
The studies were carried out using the digital platform DigitalPsyTools [38, 39]. The system is both a digital platform with a web interface and a psychodiagnostic tool used for population research in the education system. Platform-independent evaluation functions are built into the elements of its web interface. Between the application of an external stimulus and the corresponding motor response, there is a certain period of time for the stimulus, called the reaction time. Estimation of this time is one of the important methods of studying the rate of cognitive processing of information by a person and the coordinated response of peripheral movements. Many factors affect the reaction time, such as age, physical condition, fatigue, health, etc. Longer response times mean reduced productivity. For this study, the reaction time is the timespan from the start of the web page presentation on which an action can be taken to the time when the user performed this action in the interface. In other words, reaction time is the timespan from the stimulus appearance to the moment when the user presses the corresponding button (based on psychological terms). The fragment of a large psychological survey among first-year students from 20 different universities is presented. During the survey, students answered various questionnaires and passed cognitive tests; at the same time, a study was organized on the built-in reactions to answers to simple questionnaire questions. Not only was the answer recorded, but also the time spent on the answer, including reading the question and choosing the answer in the presented web interface. The hypothesis was that reaction times of different responses with different user interface elements are personal. The hypothesis of the analysis of data on the reaction time consisted of the possibility of determining the dependence in the reactions of users when working with interface elements when answering a question asked, as well as the possibility of determining individual psychomotor reactions when working with the interface. During the survey, students were presented with the following three questions, among others:  
1. Study program (choice of four options: bachelor's/master's/specialty/postgraduate study). 2. Basis of training (choice from three options: budget/contract/target). 3. Indicate the profile of your education (choice from four options: technical/humanita rian/natural science/no profile). Questions 1 and 2 were asked at the beginning of the survey. Question 3 was asked one hour after the survey began. The questionnaire is organized as a web interface. After receiving the polled archive, it is unpacked and downloaded to the browser on the client's device. In each element of the survey, the answer and the response time are recorded in milliseconds (from the moment of loading until the choice of the answer and pressing the button \"next\"), i.e., the time during which the user read the question, considered the given options and selected the appropriate option. The survey was large and included cognitive tests, and the user was interested in going to the next page. Data were transferred to the platform after the end of the entire survey or after the user closed the web page. This ensured that the networks did not interfere with the response time estimation. The total number of students who participated in the survey was equal to 23,102. Figure 2 demonstrates the histograms of the reaction time to Questions 1-3. Records containing empty answers or reaction times lower than 2 s were withdrawn from the dataset. The remaining 22,357 records were normalized, and the mean values for each question were calculated. Then, the new dataset was generated containing the deviation from the mean reaction time for each student according to each question. That dataset of deviations was then processed as the object for analysis. To assess the students' reaction time deviations qualitatively, we introduced a scale dividing the deviations into four quartiles in ascending order.