MICROTEACHING AS A SELF-LEARNING TOOL . STUDENTS ’ PERCEPTIONS IN THE PREPARATION AND EXPOSITION OF A MICROLESSON IN A TISSUE ENGINEERING COURSE

Microteaching is a didactc tool of recent applicaton to undergraduate and postgraduate students as a way to promote self-learning. In this work we compared the perceptons of the students who provide instructon in tssue engineering using microteaching and the perceptons of the same students when they receive such instructons. Two similar questonnaires with items related to the preparaton and expositon of a microlesson were used to investgate the percepton of 56 students before and after the microteaching session. In our results, students signifcantly prefer to use specifc objectves, textbooks and Internet informaton when they are preparing a microlesson as compared to the situaton when they receive it. On the other hand, the use of a pre-programmed index during the expositon and the reducton of the use of slides are signifcantly more preferred by the students after receiving the microlesson. No statstcal diferences were found for the rest of the optons analyzed. These results show that the self-assessment generated in the microteaching session, which is linked to the feedback related to the self-learning process, makes microteaching a technique not only useful for self-learning but also an important tool to promote self-regulaton across the curriculum.


INTRODUCTION
The use of microteaching as a didactc tool was introduced during the last decades of the past century as a way to improve the skills of the teachers (Ananthakrishnan, 1993;Macleod, 1987;Perrot, 1976).Recently, microteaching was implemented in diferent curricula as a useful self-learning instrument in undergraduate and postgraduate students (Cliford & Edwards, 1975;Kamboj, Kamboj, George, & Jha, 2010;Popovich & Katz, 2009;Sana, 2007).As it is well known, self-learning involves the actve partcipaton of the students and encourages them to construct their own learning program (Campos-Sánchez, Martn-Piedra, Carriel, González-Andrades, Garzón, Sánchez-Quevedo et al., 2012).Self-learning techniques are able to place students at the forefront of their own learning process, making learning more efectve, efcient and meaningful (Campos-Sánchez et al., 2012;Gaikwad & Tankhiwale, 2012).In higher educaton, self-learning promotes actve learning and critcal thinking, which may efectvely reinforce knowledge and skills (Gaikwad & Tankhiwale, 2012).However, these techniques require periodical guidance by mentors, and their applicaton to novel disciplines such as tssue engineering has not been well explored yet.
Microteaching involves a simulated teaching session known as microlesson of fve to ten minutes of duraton in which students teach a short lecture to their classmates (Ananthakrishnan, 1993).Microteaching-microlearning exercises are efectve methods to enhance and develop communicaton, problem-solving and critcal-thinking skills in students (Popovich & Katz, 2009).In traditonal recepton learning strategies, a lesson is considered as an educatonal tool based on the partcipaton of a teacher or instructor who transmits informaton to the students.In contrast, a microlesson is elaborated and taught by the students, who present the informaton to other students without systematc external guidance.For that reason, microlessons should be categorized as educatonal tools in the context of self-learning (O'Brien & Shapiro, 1977).In this sense, microteaching techniques focus on the same fnal goals that other types of self-learning techniques used in higher educaton such as virtual learning (Shaw & Friedman, 2012) and self-discovery learning (Campos-Sánchez et al., 2012), although the methods used are diferent.Tissue engineering is an emerging science that applies the principles of engineering, medicine and life sciences to the generaton of biological substtutes (artfcial tssues, bioengineered tssues or tssue constructs) to restore, maintain, or improve tssue functons.Although the term Tissue Engineering was introduced in the eightes (Skalak & Fox, 1988), the concepts of tssue engineering and its development and applicaton have been increasing since the work published by Langer and Vacant (1993).Currently, the constructon of artfcial tssues by tssue engineering is becoming a reality, not only as a basic research line, but also as a frst-rate industrial actvity destned to have a huge impact on the economy and development of more advanced countries.In this context, the subject "Tissue engineering" is an open electve subject at our University in which a microteaching method of educaton has been implemented as a self-learning method of instructon.The goal of this study was to assess the perceptons of how the students who provide instructon using microteaching would design such actvity and to compare these with the perceptons of the same students when they receive such instructon.The study of the perceptons of the students in both circumstances could contribute to develop and implement a self-learning program using this instrument.This is especially important because the student's perceptons are not only at the base of self-learning but also because they could be a reference to defne the students' expectatons regarding the tasks and skills they should acquire in their learning process (Chan, 2011;Schommer, 1990;Wolters, 2004).

METHODOLOGY
This study was performed at the University of Granada, in Granada, Spain.The sample consisted in 56 thirdyear undergraduate medical students enrolled in the electve ''Tissue engineering'' course.None of these students had previously worked with microlesson tools.Before beginning the present study, instructors briefy explained to the students the objectves of microteaching as a self-learning tool (Ananthakrishnan, 1993), and pointed out the diferent possibilites that the students could use to implement this technique.No references or demo-examples were used.
In this work, two diferent questonnaires were used to evaluate the perceptons of the students.The frst questonnaire consisted of ten items related to the queston "To prepare a microlesson you would use:".The second one had ten items related to the queston "To expose a microlesson you would use:" The specifc items included in each questonnaire are shown in Tables 1 and 2. The responses in both questonnaires were recorded with a symmetric agree-disagree Likert-like scale on which students indicated their level of agreement or disagreement for each item.Each partcipant rated each opton on a fve-point Likert scale from 1 to 5, with each score corresponding to the following level of agreement: 1: strongly disagree; 2: disagree; 3: neither agree nor disagree; 4: agree; 5: strongly agree.
Both questonnaires were completed by the students twice.The frst tme (Q1), the questonnaires were presented to the students in charge to prepare and teach a microlesson in order to evaluate their preferences on how to prepare and carry out the microteaching, before this actvity was completed.The second tme (Q2), the same questonnaires were answered by the students who had already received the microlessons in order to analyze their preferences as students and recipients of informaton.
For each questonnaire and for each specifc item, mean results and standard deviatons were calculated for all partcipants.Percepton diferences between the Q1 and Q2 results were identfed by using the Mann-Whitney non-parametric statstcal test using the SPSS 15.0 software.P<0.05 was considered as statstcally signifcant for the double-tailed tests.

RESULTS
The average scores obtained for each item in both questonnaires are shown in Tables 1 and 2. The lowest scores in the frst and second questonnaire were found for the items "to prepare a microlesson, you would use internet informaton" and "to expose a microlesson you would use the same tone of voice", both in Q2 (students who had received the microlesson) (scores 3.16 ± 1.15 and 1.85 ± 1.08, respectvely).The highest scores corresponded to the items "to prepare a microlesson, you would use specifc objectves" (4.80 ± 0.44) in the frst questonnaire and "to expose a microlesson you would use the relevance of the topics" (4.55 ± 0.56) in the second questonnaire, both in Q1 (students who are preparing to teach a microlesson).
Interestngly, the Mann-Whitney test revealed statstcally signifcant diferences between Q1 and Q2 regarding fve of the optons: "To prepare a microlesson you would use specifc objectves", "To prepare a microlesson you would use textbooks" and "To prepare a microlesson you would use internet informaton" in the frst questonnaire, and "To expose a microlesson you would use a programmed index" and "To expose a microlesson you would use slides", in the second questonnaire.No statstcally diferences were found for the rest of the optons.Figure 1 shows the optons that yielded statstcally signifcant diferences for the comparison of Q1 vs. Q2.

DISCUSSION
The applicaton of microteaching as a self-learning method to tssue engineering is of interest not only as a way for students to acquire new competences and skills but also because tssue engineering is a multdisciplinary feld that requires major teaching synthesis eforts (Sánchez-Quevedo, Cubero, Alaminos, Crespo & Campos, 2006).In the present work, we have analyzed the perceptons of the students in the preparaton and expositon of a microlesson in a tssue engineering course.Although the study has several limitatons, including the possibility that even a brief previous informaton might afect the results, it could shed light on our comprehension of the students' preferences involved in microteaching.
In our results, the percepton of students involved in teaching and receiving a microlesson was similar for most of the items analyzed in both questonnaires.This means that in most of the items, students do not change their perceptons about preferences on how to elaborate a topic for teaching and how to expose it, before and after a microteaching session.This result implies that the applicaton of microteaching method is useful because it will strengthen the beliefs about the teaching and learning procedure that the students previously had, and therefore, allows them to be more involved and committed with their own learning process (Gelula & Yudkowsky, 2002;Trott, 1976).
However, in our results, the percepton of students also revealed statstcally signifcant diferences, before teaching a microlesson and after receiving it, in several items: three items regarding the preparaton of the microlesson and two ones related to its expositon.
Interestngly, students consider they would use more signifcantly specifc objectves, textbooks and Internet informaton before preparing a microlesson than after its recepton.This could be linked to the informaton that the students consider that should be incorporated to a microlesson and to the objectves that they believe they should reach before the microteaching session.When receiving the microlesson they realize that it is impossible to teach efciently with such extensive informaton.Regarding the expositon, the students showed signifcant diferences in the use of a previously programmed index and in the use of slides.Following a preprogrammed index during the expositon and a limited use of slides are more preferred by the students after receiving the microlesson.It is paradoxical and very interestng that students give less importance to the expository order when they are preparing the microteaching session than when they are receiving it.Similarly students want less slides when they receive the microlesson that when they are in charge to prepare the microteaching session.Nevertheless, the ultmate reasons why certain items are preferred by students remain unexplained, and future qualitatve studies should be carried out to investgate these reasons.
Although microteaching was initally addressed to young teachers to improve their pedagogical techniques under supervision of skilled colleagues, the extension of this technique to the students as a self-learning tool has demonstrated to be very useful to change the student's behavior and therefore, their attude towards the learning process.As shown in our study, the main reason for this change could be in the process of selfassessment that students do.As pointed out by Popovich and Katz (2009), microteaching technique not only helps students to ''think on their feet'' and be refectve, but it also provides an opportunity to get a constructve feedback.
The new teaching guidelines emphasize the need for students to engage in self-regulaton of learning and practce (Brydges & Butler, 2012;Butler & Winne, 1995).As the self-assessment is linked to how individuals seek and interpret feedback as pointed out by Sargeant, Mann, van der Vleuten and Metsemakers (2008) and Sargeant, Armson, Chesluk, Dornan, Eva, Holmboe et al., (2010), we consider that the use of microteaching techniques is not only useful for self-learning but also as a tool to promote self-regulaton across the curriculum.

CONCLUSIONS
In this study we compare the students' perceptons of the students who provide instructon in tssue engineering using microteaching and the perceptons of the same students when they receive such instructons.To know the student's perceptons in both circumstances, is a key element to develop and implement a self-learning program using this instrument.
We conclude that students prefer to use more signifcantly specifc objectves, textbooks and Internet informaton in order to prepare a microlesson than after the recepton of such microlesson.To make use of the programmed index in the expositon and to reduce the use of slides are preferred more signifcantly by the students after receiving the microlesson than when they are preparing it.These results show that the selfassessment generated by the microteaching session, which is linked to the feedback related to the self-learning process, makes microteaching a technique not only useful for self-learning but also an important tool to promote self-regulaton across the curriculum.
Figure 1.Items that showed statistically significant differences for the comparison of Q1 (before the microlesson) vs. Q2 (after the microlesson) responses.Responses corresponding to Q1 are shown in blue and Q2 responses are in red.Black bars represent standard deviations