The objective of the present research was to conduct a literature review of articles related to comparative studies dealing with critical thinking in universities and how it might influence students. Reliable search sites such as Scielo, Dialnet and Google Scholar were used to compile the information. Part of the research also sought to determine if in this compilation, the results of the selected studies would have similar conclusions, thus identifying a common denominator. This common denominator would be that critical thinking skills would indeed have an influence in the different careers, regardless of the cycle, and that, not being sufficiently developed, it would also be noticed. This influence would also be related to methodological practices and to the specific demands of each university career profile, one of the most notable being the decision-making ability, as will be seen in some of the conclusions. This study also suggests the implementation of methodologies that can develop critical thinking skills, an aspect that appears indirectly in the research.

Keywords: Comparative study; critical thinking; university students.

Critical thinking is a skill that is always being sought to develop and it is often assumed that in the university environment there will be a great opportunity for this to happen in a convincing way. This does not mean that this can always be achieved, but it is an alternative that we cannot leave aside. Perhaps, this notion of development is very generalized to the extent that the university always gives us tools not only in the academic, formative, intellectual or professional field, but also gives us the perspective of being able to perceive life in another way. Therein lies the nexus in which the different skills should be developed, therefore critical thinking is also involved. How they would be developed is a question that we should keep in mind and this would be associated either in the methodologies used by professors in the teaching of classes, as well as in the daily life of university life itself and its coexistence within the cloisters (Salazar, 2020).

Now, the purpose of this article is not to see which or how is the development of critical thinking but to make a literature review on comparative studies and the relationship of this skill among university students and their results, if any. For this reason, it is essential at first to define what we mean by critical thinking; since it comes to have different concepts as Bezanilla et al. (2018) makes known. Being able to define critical thinking can become a bit complex, if we go back to this titanic task, and appealing to Gonzales & Morillo (2018) and they citing Dick (1991) indicate that this idea has been expanding over the years, counting that there were a total of 15 concepts between the years 1940 and 1990. For his part Bezanilla et al. (2018) in his study where he indirectly made an account of the concepts of critical thinking, cites Sternberg (1986) where he states that they would be processes, planning and symbolization, what he understands by critical thinking and that it is used by people for problem solving, making decisions and learning new notions. Later, he would also comment on Ennis, Bloom, Paul and Elder and Facione. It is important to mention what is indicated by Sternberg, because one of the concepts that seeks to associate critical thinking as a more general concept will be reasoning, problem solving and decision making, the three as one.  For his part Morales (2018), would see critical thinking as that which has a goal, thus having a purpose, thus being reasoned, while Anchundia & Avilés (2018) indicate that critical thinking will be a process that in daily life is constantly found, helping to make decisions through reflection.

On the other hand, it is important to explain what comparative studies consist of and what their purpose would be. To begin with, it should be pointed out that the purpose of comparing is to be able to analyze and differentiate the different characteristics that exist between what is being compared. But what is the purpose of comparing or what is being compared and where this comparability would be directed. The prompt answer would be that, this, comparing, is not something new, but has always been immersed in our lives as a piece of gear, a way to know and correlate with others and what comprises the world. But we must not understand what has been written so far in reference to comparative studies as a mere comparison, but we must make it clear that we should not see or understand it as a simple thought, as schemes that are given in our head under prejudices; although what we seek is a knowledge of the social and natural. When we consider comparative studies, we must understand that they are studies in reference to science and facts of daily life but that they have a systematic procedure in their objects of comparison and it is not random. It is governed by the choice of the objects of study, how they are selected and the properties to be compared and how the analysis of the data used to make such comparisons is carried out, as indicated by Piovani and Krawczyk (2017).

In order to simplify it, when we could talk about comparative studies, we refer to the fact that objects are compared, whether institutions, countries, cities, groups of subjects, etc.; but focusing on a characteristic of them, how they are at that moment and when such comparison is hard.

In accordance with comparative studies, we cannot leave aside what comparative education is, being this what concerns the present investigation, for this we must indicate that it comes from the science of education and that it seeks to compare the educational processes, being a tool of the educational policy with the purpose of being able to close gaps from the results that are achieved. It is also understood that all the information obtained from this study had to go through a data collection, classification, description and quantitative and qualitative analysis, depending on the study that has been proposed, and after that, I seek to observe if there was any particularity in these research processes. We cannot leave aside that we must understand that each context is unique and that the results, which are unique, help to make decisions regarding the difficulty to be overcome and objectives to be consolidated, either to develop education from the diversity of contexts, unification, etc. (González & Collazo, 2019).

The research that was carried out consisted of a bibliographic review of descriptive design in comparative studies on critical thinking in university students that starts from the year 2017. For the search and collection of information, the following databases were used: Scopus, Scielo, Dialnet, Google Scholar, where the descriptors were: comparative studies, comparative studies, comparative education, critical thinking, university education. We also searched for approximations to the terms mentioned, being a not minor detail, to review articles dealing with critical thinking in higher education and to observe whether comparisons were made between different university careers, different cycles, sex, control groups, but all dealing with university education and critical thinking. It is also understood that not including comparative studies in the titles of the articles made the search very complicated, which is why the approximations to the titles and seeing the methodology of research works, such as reading the abstract, helped a lot in the search. We cannot fail to point out that comparative studies are not very common, being therefore a factor that undertook the realization of this article that is presented below.

Therefore, after an incessant search, only articles were considered (without taking into account theses, papers, essays, publications in newspapers, opinions, duplicity of articles or unreliable sources); in order to give it greater scientific validity, obtaining as a result the number of 9 articles, after discriminating and placing filters such as year of publication and that they have the scheme of scientific research.

In the table that we present from the bibliographic review that we have carried out, we can visualize how comparative studies in reference to critical thinking in universities and therefore, their relationship with university students have been able to draw conclusions. We cannot fail to indicate, what comparative studies in education or also called comparative education, is of utmost importance to be able to find the gaps that may occur within society or how educational policies are handled in different parts of the world (González & Collazo, 2019). The contribution that they will give to close these dissimilarities can give us a perspective not only from the social sciences as already raised by Piovani & Krawczyk (2017) but the applicability that can be given in education.

But returning to the authors of which we have made a bibliographic review, it is striking that comparative studies have been made or at least more information has been found regarding the medical school or health sciences. As evidenced by authors, for example, De la Portilla et al. (2022), in their research, initially sought to measure and then compare whether critical thinking and metacognitive awareness were correlated. For this, his study group was divided into two groups, the first group, which would be the first semester, had 22 students and the second, the last semester, had 20 students. The result that would be obtained would be that there is a correlation between both skills regardless of the semester.

In correlation with the previous research, the authors Albarrán & Díaz (2021), conducted a study in agreement between the implementation of active methodologies such as problem-based learning, project-based learning and case studies, seeking to find if these methodological activities could promote critical thinking in first and second year medical students, which were divided into a control group and three experimental groups, resulting that there is a correlation and an influence on learning and development of critical thinking.

Another study, which supports what has been said about the comparative studies between critical thinking and university education, is that of Chávez et al (2020). The authors conducted a study in which they sought to determine whether the skills that are products of a clinical simulation could coincide with critical thinking skills, one example being decision making. For this purpose, they were divided into two groups, those who participated in a clinical session and those who did not. The first group belonged to the sixth cycle and the second to the seventh cycle of the Faculty of Medicine.  The results were that the differences were not as significant as in the dimension of information analysis and interpretation. 

In another published work, but previously De la Portilla et al. (2019), we find that a comparative study was conducted between students of the first and tenth semester of the Faculty of Medicine, which seeks to evaluate the different cognitive skills of critical thinking, reaching an average level. And finally, the work done by Hincapié et al. (2018) identified and compared two groups, one where PBL is used and the other where traditional teaching is given, in order to demonstrate whether critical thinking is developed with this methodology. In both groups, both women and men were considered, with the result that this methodology does influence critical thinking skills and that their learning increased considerably. As we can see up to this point, the comparative studies presented are in reference to critical thinking within the university, but in the School of Medicine. This does not mean that we have only been able to find information about this faculty, but we cannot help but express a certain astonishment.

On the other hand, the Faculty of Engineering was also part of some comparative studies, proof of this is the research conducted by Mayor et al. (2022); where they sought to determine whether there was any correlation between understanding mathematics and critical thinking in students of the Universidad Nacional del Centro del Perú, exactly in the Faculty of Mining Engineering of semesters I and II, reaching conclusions that the results are minimal unlike the comparative studies presented above.  Contrasting the results given is Steffens et al. (2018), where I conducted comparative research between students of semesters IV, V, VI of the Faculty of Education and critical thinking. What he sought to know was whether this skill could influence such students regardless of the semester where they were, concluding therefore that there would be such influence.

A faculty that could not be exempted from some kind of comparative study on critical thinking could not be that of Law. As we know, part of their tools for their performance in the workplace is that they can count on skills such as problem solving, arguing, hypothesizing, among other actions, that is where the study conducted by Betancourth et al. (2017) where they sought to determine whether the students of the Faculty of Law of a university in Chile possessed any level of critical thinking, dividing between low, average and high, selecting for this purpose the skills of decision making, probability, argumentative analysis, hypothesis testing and verbal reasoning, skills that are part of critical thinking and obtaining as a result a low level.

In order to conclude with these studies, we cannot leave aside the deep systematic research conducted by Delgado et al. (2019) where it was determined and identified through comparative studies if students, first selecting them by careers and then distinguishing between men and women, if they had any predisposition for critical thinking, using for this purpose the skills of truth seeking, systematicity, confidence to reasoning, analytical skills, mental breadth, curiosity, etc. One of its first conclusions is to indicate that there was no significant difference in the different careers that were evaluated, such as health sciences, humanities, legal and social sciences, engineering, economic sciences, except in the skill of curiosity, where the students of humanities and legal and social sciences would have a much greater disposition towards curiosity, compared to the others. On the other hand, distinguishing between men and women, significant differences were found when it comes to analysis, which would be enriching in this research.

As we can see, comparative studies help us to observe the topics we investigate from a different perspective, in some cases visualizing fissures that would not be easy to see at first glance. In this case, we have been able to witness that critical thinking is present in the different university careers, and proof of this is that it can be measured, without being subject to this or that university career. Secondly, its influence, even if it has been minimal or null, can be evidenced by not carrying out certain activities such as problem solving. A third conclusion would be that in the studies presented, the medical career would be the one in which most research has been carried out. It is inferred that this is due to the fact that they are constantly making decisions in cases of extreme urgency and that they must be prepared according to the circumstances. A fourth conclusion is that, in the studies carried out by the authors, they would be indirectly stating that actions should be applied for the development of critical thinking, this being perhaps contradictory, since we have not found much comparative study material on critical thinking in the university environment. We cannot fail to mention that we, as human beings, will always seek to solve the obstacles we face in the shortest time possible or, as well, to make decisions, and this is related to critical thinking. A final conclusion is that, to a greater degree, having a level of critical thinking or being able to demonstrate it when carrying out these comparative studies, is associated with better academic performance, and although this influence was not evident in all the results of the research presented, not having a high or average level would affect performance.

Limitations: The limitations found in the present research refer to the available material, being this, as already mentioned, difficult to locate due to the fact that the titles do not explicitly include terms such as 'comparative studies' or 'compared', or any word that could help to associate them. This fact represented a serious obstacle for our research. On the other hand, some of the studies we found were not in reliable pages, which was a criterion for not considering them, given the rigor of our research. Another limitation we encountered was that some publications had already been published for more than 5 years, which was another criterion for delimitation in the present investigation.

Contribution to scientific knowledge: The present research serves as reference material for future researches who wish to go deeper into the subject or go deeper into it, since it has fulfilled all the requirements of a scientific research. Let us remember that an alternative to obtain an accurate knowledge of things are those investigations that comply with the scientific methodology. Therefore, by providing this contribution on comparative studies, we assume that it is a contribution to scientific knowledge.

Conflicts of interest: The authors declare that they have no conflicts of interest.

Authors' contribution:
Sotomayor, E: Conceptualization, Formal analysis, Methodology, Research, Supervision, Writing - original draft, Writing: revising and editing.

Informed consent: Not applicable

Data availability statement: Not applicable