In this group, students' stress levels before entering the first station in the OSCE will be determined using the State Anxiety Inventory and a smartwatch. Immediately afterward, while the student is performing IV catheter insertion at the station, the procedure steps will be evaluated by the instructor using a Skill Checklist. At the end of the procedure, students' stress levels will be re-evaluated using the State Anxiety Inventory and a smartwatch.

Students will be assigned to experimental and control groups based on their knowledge test scores using block randomization. The following day, all students will be taken to the laboratory for practice. The instructor will demonstrate IV catheter insertion once on a mannequin, following the procedural steps, and then students will work with the instructor in groups of eight. Each student will practice the procedure on the mannequin at least once. Students in the experimental group will undergo OSCE (Obstructive Skills Test). The OSCE will be prepared in a laboratory setting with two stations where students will practice their skills. Students will be asked to perform IV catheter insertion at the first station. At the second station, students will perform a procedure chosen by lottery. Students will not be evaluated on the skill at the second station. Students will have 5 minutes to perform the skill at each station. A bell will ring every 5 minutes, and students will move from one stat

At the beginning and end of the program, students' stress levels will be reassessed using the State Anxiety Inventory.

The Visual Analog Scale for Stress (VAS): Based on the logic of subjectively marking the intensity of a specific emotional state on a one-dimensional line, it has become widely used over time in measuring variables such as pain, anxiety, and stress. The VAS form used specifically for stress was developed to determine the immediate stress level felt by participants in a practical, rapid, and highly sensitive manner. The scale is applied by placing a single mark on a 10 cm long line between the endpoints "I am not stressed at all" and "I am currently feeling very stressed." This mark is measured in millimeters from the left end and converted into a numerical score between 0 and 10; this structure minimizes the workload for participants while providing researchers with high-resolution, continuous data.

During the activity, the skills of students in both groups will be assessed using a checklist.

Intravenous Catheter Insertion Skill Checklist: Prepared by researchers in accordance with the literature. The final version was then finalized after obtaining the opinions of 10 academics specializing in the Fundamentals of Nursing. The intravenous skill checklist consists of a total of 27 procedural steps. Each step is evaluated as "correctly performed" (1 point) or "incorrectly performed" (0 points).

At the beginning and end of the practice, physiological stress levels will be measured using a smartwatch. For smart measurement, a Huawei Watch Fit 2 device will be used, employing a wrist-based optical heart rate sensor (HUAWEI TruSeen™ 5.0) and the HUAWEI TruRelax™ algorithm based on HRV (heart rate variability). Thanks to this algorithm, the watch transmits the results of low-level stress (1-29), normal-level stress (30-59), moderate-level stress (60-79), and high-level stress (80-99) to a mobile application on the researcher's cell phone.