FL will be applied to the intervention group. In this model, short videos of the course will be delivered to students via WhatsApp one week in advance. At the beginning of the lesson, students' deficiencies will be corrected by making kahoot. Afterwards, group work, case scenario, role-play scenario and conceptual map methods will be applied in the course.

The subject of the nursing process will be transferred to the control group with powerpoint presentations by the educator. The activities in the other group will be presented by the trainer as an example.

FL was applied by Jonathan Bergmann and Aaron Sams in 2007 for high school students who had to be absent from chemistry class. Bergmann and Sams published all the learning activities they used during the lesson as videos. Bergmann and Sams (2012) stated that in this model, which they developed over time, it is not compulsory for the trainer to explain the entire course content in the videos, and the important thing is to allocate time to active learning methods during the course. In the FL model, the summary of the course content is presented to the individuals outside the classroom with tools such as video and power point presentations. In the lesson, activities are carried out for the active participation of the student. The student performs the course content outside of the classroom, and the homework and learning the course in the classroom.

In this study, the "Critical Thinking Tendency Scale (CTTS)" developed by Semerci (2016) was used. The Cronbach's alpha internal consistency coefficient of the CTTS scale was determined as 0.96. This scale consists of 49 items scaled as "I totally disagree (1)", I mostly disagree (2), I partially agree (3), I mostly agree (4), I totally agree (5)". The CTTS total score ranges from 49 to 245. It was stated that the students who scored high on the scale had a high tendency to think critically. (Semerci 2016).

The Problem Solving Inventory used in the research is one of the tools that measures the individual's own perception of problem solving skills. The Cronbach's alpha internal consistency coefficient of the PSI scale was determined as 0.88. The Turkish adaptation of the scale developed by Heppner and Petersen in 1982 was carried out by Şahin, Şahin and Heppner (1993). A high total score from the scale indicates that individuals perceive themselves as inadequate in problem solving, while a low total score indicates that individuals perceive themselves as sufficient in problem solving skills

Semi-structured focus group interview forms were used in the qualitative part of this study, which was conducted with a mixed research design. Focus group interview forms contain open-ended questions and allow new questions to be added when there is a need to deepen on a topic during the interview. Interview questions were prepared by the researcher as a result of the literature review. Afterwards, opinions were taken by two different experts, and necessary adjustments were made in the focus group interview form in line with these opinions. The final version of the interview form consists of six open-ended questions.