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Comparison of two teaching methods in
immunology for medical students: a
quasiexperimental study with nonequivalent
control group
Comparación de dos métodos de enseñanza en
inmunología para estudiantes de medicina: estudio
cuasiexperimental con grupo de control no equivalente
Washington Paz-Cevallos
Universidad Central del Ecuador, Quito, Ecuador
Facultad de Ciencias Médicas, Carrera de Medicina
wrpaz@uce.edu.ec
https://orcid.org/0000-0002-7599-5781
Marcos Jiménez-Córdova
Universidad Central del Ecuador, Quito, Ecuador
Facultad de Ciencias Médicas, Carrera de Medicina
majimenezc1@uce.edu.ec
https://orcid.org/0009-0008-7928-1779
Mary Ordóñez-Asanza
Universidad Central del Ecuador, Quito, Ecuador
Facultad de Ciencias Médicas, Carrera de Medicina
mlordoneza@uce.edu.ec
https://orcid.org/0009-0006-8847-3436
Teresa Haro-Blacio
Universidad Central del Ecuador, Quito, Ecuador
Facultad de Ciencias Médicas, Carrera de Medicina
tmharo@uce.edu.ec
https://orcid.org/0009-0007-7356-9563
(Received on: 28/03/2025; Accepted on: 06/05/2025; Final version received on: 08/01/2026)
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Suggested citation: Paz-Cevallos, W., Jiménez-Córdova, M., Ordóñez-Asanza, M., y Haro-
Blacio, T. (2026). Comparison of two teaching methods in immunology for medical students:
a quasiexperimental study with nonequivalent control group. Revista Cátedra, 9(1), 18-34.
Abstract
The chalk talk and slide projection methods in biomedical science lectures show differences
in student learning in the short and medium term, which impacts future therapeutic
decision-making in favor of the patient. A 2017 study by the Faculty of Medical Sciences at
the Central University of Ecuador reported that 50% of students did not fully understand
the lectures. Therefore, a quasi-experimental operational study with a non-equivalent
control group was conducted with first-semester medical students during the 2024-2025
academic year to compare the effectiveness of both methods in short- and medium-term
learning. Participants were assigned to the interventions: chalk talk and slide projection;
and received a Basic Immunology lecture using the respective methodology. Each group was
evaluated before, immediately after, and one week after the lecture. The level of learning
was estimated using a 20-point test specific to the course. The chalk talk group improved
from a pre-intervention mean score of 5.07 ± 2.76 to a post-intervention mean score of
12.92 ± 3.86 and scored 8.33 ± 3.68 one week later (p < 0.05). The slide group improved
from a pre-intervention mean score of 6.06 ± 3.29 to a post-intervention mean score of 8.76
± 3.19, with a score of 6.93 ± 3.57 one week later (p < 0.05). It was concluded that the chalk
talk method is more effective than slide projection in the short and medium term for
teaching medical students, with no influence from IQ or gender.
Keywords
Chalk talk, slides, teaching, quasi-experimental, immunology, medicine, blackboard.
Resumen
Los métodos chalk talk y proyección de diapositivas en clases magistrales de ciencias
biomédicas muestran diferencias en el aprendizaje de los estudiantes a corto y mediano
plazo, lo que repercute en la futura toma de decisiones terapéuticas a favor del paciente. En
un estudio de la Facultad de Ciencias Médicas de la Universidad Central del Ecuador en
2017, se reportó que el 50% de estudiantes no comprendía totalmente las clases
magistrales. Por ello, se realizó un estudio operativo cuasiexperimental con grupo de
control no equivalente, en estudiantes de medicina de primer semestre periodo académico
2024-2024, con el objetivo de contrastar la efectividad de ambos métodos en el aprendizaje
a corto y mediano plazo. Los participantes se distribuyeron a las intervenciones: chalk talk
y proyección de diapositivas; y, recibieron una clase de Inmunología Básica con su
respectiva metodología. Se evaluó cada grupo antes, inmediatamente después y una semana
luego de la clase en cada grupo. Se estimó el nivel de aprendizaje con test propios de la
cátedra sobre 20 puntos. El grupo chalk talk pasó de un promedio preintervención de 5.07
±2,76 a 12,92 ±3,86 postintervención, y obtuvo 8.33 ±3,68 una semana después (p <0.05).
El grupo diapositivas pasó de 6.06 ±3,29 a 8,76 ±3.19 postintervención, con 6.93 ±3.57 en
la evaluación una semana posterior (p <0.05). Se concluyó que el método chalk talk es más
efectivo que la proyección de diapositivas a corto y mediano plazo en la enseñanza a
estudiantes de medicina, sin influencias por coeficiente intelectual o sexo.
Palabras clave
Chalk talk, diapositivas, enseñanza, cuasiexperimental, inmunología, edicina, pizarra.
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1. Introduction
Education is understood as an act of “instruction through teaching” (Royal Spanish
Academy, 2025). It is a process that unfolds across different levels, from primary school to
higher education, each with its own strategies and goals, though always involving both
teachers and students (Biesta, 2020, p. 89). Beyond preparing individuals to integrate into
society, education seeks to foster lasting learning, providing tools for individual and
collective professional development. Flores et al. state that teachers must be constantly
updating their skills; professional careers such as medicine and nursing, for example,
require mastery of the physiological functioning of the human body through the basic
biomedical sciences learned at the undergraduate level (Flores et al., 2021).
The central problem addressed in this study is the variability in the effectiveness of chalk
talk and slide projection models in teaching basic biomedical sciences. Although both
methods are widely used, some authors, such as Parashar et al. (2018), suggest that “a
disadvantage of PowerPoint appears to be that the student becomes a passive observer
rather than an active participant” (p. 4). However, opinions are divided. Saca and Tituaña
(2016) maintain that this same technique “encourages students to take initiative in their
own learning” (p. 23).
Therefore, this operational study was conducted to analyze and compare the effectiveness
of these two pedagogical models to determine which offers a greater advantage in the
teaching and learning process of basic biomedical sciences. Specifically, it focuses on basic
immunology in first-semester medical students, considering sex and IQ range as moderating
variables.
Regarding the structure and content of the article, the second section delves into a literature
review of the available information on teaching and learning models. The third section
describes the materials, subjects, and methods used for the operational experiment. The
fourth section details the results obtained from the interventions. The fifth section
compares these results with those found in similar studies and presents a discussion and
conclusion.
2. Literature review
2.1 The teaching and learning process
“The teaching-learning process is conceived as a deliberate communication system that
involves the implementation of pedagogical strategies to foster learning” (Osorio et al.,
2021, p. 2). In this context, teaching is understood as the guidance and instruction provided
by a teacher through pedagogical strategies; while learning is a dynamic and continuous
process through which the student receives, modifies, or strengthens knowledge, skills, and
practices. This process involves both neurobiological mechanisms and contextual and
emotional factors.
Authors such as Rochina et al. state that the teaching-learning process establishes a network
of complex interactions that include the relationships between teacher and student, among
students, between the student and knowledge, and between the student and their practical
environment. These interactions reflect that learning is not limited to the simple
transmission of information from teacher to student, but rather is a collective process
involving multiple theoretical, practical, and relational factors. Currently, based on the
teacher's role, some authors assert that these activities are carried out in groups, with an
approach that integrates theory, practice, and social interaction within the classroom. They
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also state that, in general, knowledge construction is based on problem-solving, which
fosters both the individual and collective development of the participants (Rochina, et al.,
2020, p. 388).
The teaching-learning process naturally involves various actors and elements. Among the
human factors, the teacher and the student stand out. The teacher is responsible for
planning, organizing, and facilitating learning through appropriate pedagogical strategies.
They must carry out the didactic act, which is "the concrete realization of the teaching
process; that is, the materialization of said process in time and space" (Meneses, 2007, p.
61). Their role not only involves the transmission of knowledge but also the guidance,
evaluation, and constant updating of their methodologies. For their part, students are
ideally active agents in their own learning, responsible for assimilating, analyzing, and
constructing their own knowledge, developing research and critical thinking skills.
Meanwhile, the non-human elements that influence this process are content, tools, and
context. Content encompasses the educational objectives and the theoretical and practical
knowledge imparted, as well as fundamental values and attitudes, such as effort, reflection,
and decision-making. On the other hand, according to Vargas, tools include diverse teaching
strategies and resources, such as reading, writing, oral expression, problem-solving,
research, and collaborative work (Vargas, 2017). And the context, which is conditioned by
factors such as physical space, the number of students, the availability of economic and
educational resources, as well as external aspects such as stress or fatigue, can affect
academic performance.
Meneses also raises other non-human elements, such as educational resources, which play
a key role in teaching, as they facilitate student understanding and interest. These resources
include printed texts, audiovisual materials, interactive whiteboards, and information and
communication technologies. In particular, interactive whiteboards, such as the traditional
blackboard and interactive materials, as well as the use of slides and audiovisual content,
are widely used tools in current educational processes (Meneses, 2007, p. 32).
Consequently, if the focus is on higher education, pedagogical and andragogical models play
a leading role among teaching strategies; the existence of several models has “created
confusion among teachers and administrators, since they all refer to education” (Correa &
Pérez, 2022, p. 131). There are several pedagogical approaches that describe how the
teaching-learning process is carried out. Therefore, when compiling the attitudes and
practices of university classes, the authors, citing Zubiría, ultimately classify pedagogical
models into three main approaches: “self-structuring, intra-structuring, and hetero-
structuring” (Correa and Pérez, 2022, p. 131).
2.1.1 Self-structuring current
The self-structuring approach is based on the idea that "the student develops autonomously
as the artisan of their own learning, being the core and sole agent of didactic transposition"
(Not, 1992). In other words, the student transforms the technical knowledge obtained
through their arduous research into assimilable or less specialized concepts, thus retaining
the new knowledge and even sharing it with others, becoming the student's own educator
on the subject. Dupouy argues that this approach includes theories such as social cognition,
active learning, information processing theory, and constructivism. He mentions that these
theories highlight the importance of the student's active and personal participation,
experimentation, and lived experience for understanding knowledge. It also considers the
student's individual characteristics, differentiating traits, and their particular concepts
about situations, words, phrases, and facts (Dupouy, 2023).
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To achieve this, according to Vergara and Cuentas, students should be encouraged to
acquire knowledge through observation, processing of new information, and application in
practical situations, progressing from simple to complex concepts based on their own
experience, thus making the student the architect of their own knowledge construction
(Vergara and Cuentas, 2015, p. 918). However, this approach can be influenced by the
institution, impacting the creation or reconstruction of knowledge. In the classroom,
teachers will use methods according to the student's interests, needs, and motivation,
fostering in them a desire to investigate a particular topic independently.
2.1.2 Intrastructural current
According to Dupouy, the focus of this approach is on personalized learning, adapting the
educational process to the individual characteristics of students to optimize their
understanding (Dupouy, 2023). According to Gómez et al., it centers on combining active
roles for both students and teachers, emphasizing guided reflection and thus ensuring the
participation of both parties in the process. Following this proposed norm, this approach is
considered an intermediate point between the self-structuring approach described earlier
and the heterostructural approach described below (Gómez et al., 2019, p. 173).
2.1.3 Heterostructural current
In this approach, the teacher plays a central role in the transmission of information, using
repetitive and expository methods to ensure comprehension of the content. Furthermore,
every effort is made to break down the information so that the learner can reintegrate it,
thus understanding the concepts conveyed. These are heterostructuring models whose
objective is the transmission of specific knowledge, values, and culturally and socially
accepted norms. According to Gómez et al., this classification includes pedagogical models
such as connectionism, classical behaviorism, continuity conditioning, operant
conditioning, and the traditional school (Gómez et al., 2019). Correa and Pérez analyze the
proposal of teacher Julián De Zubiría, whose work advocates the transmission of knowledge,
values, and cultures accepted by society. Moreover, the traditional pedagogical model,
which includes lectures, is a representative example of this approach (Correa & Pérez, 2022,
p. 131).
In higher education, especially in basic biomedical sciences training, different pedagogical
methods are used to enrich the teaching process under the hetero-structuring approach, in
which the teacher serves as a presenter of information with the help of tools that guide their
teaching. “A blackboard is exceptionally effective as a teaching tool in the classroom and has
been frequently used in classes, while the use of transparencies with an overhead projector
is also popular” (Parashar, et al., 2019, p. 4). Petimani and Adake state that Chalk Talk
consists of the use of a blackboard by the professor to illustrate ideas in real time through
diagrams, drawings, or keywords. The teacher uses markers or liquid chalk to illustrate the
content while communicating with the students. This technique is valuable, allowing for
dynamic interaction and giving students the opportunity to take notes and analyze the
information as it is presented. Furthermore, the flexibility of chalk talk to adjust the
explanation based on the group's response and the possibility of making gradual
corrections make it particularly valuable in medical training, where a deep understanding
of complex concepts is crucial (Petimani & Adake, 2015).
Slide Projection:This refers to a method that uses a video projector to display a series of
slides prepared beforehand with programs such as Microsoft PowerPoint, Canva, Slidesgo,
and others. While this approach can be more efficient in terms of content preparation and
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organization, it can limit the time available for detailed explanation. “The professor
prepares photographic slides and distributes them to the students before class. They show
the PPT slides and explain the important points during the class” (Petimani & Adake, 2015,
p. 290).
2.2 Education in health areas
Medical education has not always been as it is known today; like most processes in our
environment, it has undergone a series of transformations at the institutional, regional, and
global levels. Just a few centuries ago, the level of technology that exists today as a support
and teaching tool for those aspiring to become doctors, nurses, or artists was the stuff of
science fiction. The following is an overview of the evolution of teaching practices in the
medical field.
2.2.1 Historical review of medical education
With the formation of the first population groups and cultures of the ancient world, valuable
documentation began of various acts that can be considered the foundations of human
medicine, starting with the recording of information that for decades had only been
transmitted verbally and practically from master to apprentice. “The first records of medical
teaching exist in ancient Sanskrit. They provide detailed information about the training of
physicians” (Fiddes, 2024). Fiddes makes a particular clarification: at that time, the main
and most famous school of thought was the “Corpus Hippocraticum,” considered the
pinnacle of medical education. Within this corpus, the Hippocratic Oath was implemented
over the years, emphasizing respect for those who were the pupil's teachers in medical
training. Galen not only revolutionized the teaching of students but also generated one of
the most remembered and widely used teaching practices today: bedside teaching. Thanks
to this renowned philosopher, surgeon, and physician, those trained in medicine became
known as physicians (Fiddes, 2024).
According to the renowned historian Pilar Cabanes, later, in the Middle Ages, medical
education was managed by monasteries and certain emerging universities. In the 11th
century, in Italy, the Salerno School initiated a process of formalizing medical education by
incorporating ancient Greek and Arabic texts. Gradually, figures from the Islamic world,
Bologna, and Paris focused on the study of specialized branches: physiology, anatomy, etc.
(Cabanes, 2023). However, medical practices remained, at the very least, bloody, disturbing,
and largely experimental. There was no clear boundary between the practice of healing and
the art of learning; the latter likely involved actions that could contradict the former.
It wasn't until the Scientific Revolution in the 16th century that the approach to medicine
changed. Renowned physicians like the Belgian Andreas Vesalius contributed fundamental
knowledge to anatomy through an extensive program of dissecting human body parts,
providing information that facilitated a more accurate understanding of the human body's
architectural structure. "The young Vesalius delved deeper into Galen's studies and found
that his anatomical descriptions did not agree" (Santillán, 2019, para. 7). During this same
period, the importance of research and experimentation as a source of new information was
emphasized. On the other side of the globe, in the New World, the Americas, medicine was
in its infancy. The continent was in a transition from pre-Columbian practices to the new
cultural impositions of the conquerors. After several years of expansion, invasion, and
colonization in the territories under the rule of the Spanish Crown, the territory that is now
Ecuador, then known as the Royal Audiencia of Quito, was the subject of a proposal to
establish a medical school, thanks to the Dominican friars:
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The initial idea of establishing medical studies in Quito originated with
the Dominican friars. Friar Ignacio de Quesada clearly recognized that
university education needed less theologians, canon lawyers,
rhetoricians, and Latinists, and more physicians. He engaged his
community and, with their help, organized a Faculty of Medicine at the
Royal University of Saint Thomas Aquinas of the Dominican Order in
Quito, founded in 1688. This faculty included a three-year curriculum and
two professors. By Royal Decree of April 13, 1693, the first Chair of
Medicine in Quito was established there, in the Dominican convent of San
Fernando (Estevez et al., 2018, p. 149).
According to Estevez's own research, throughout the history of this medical school, there
have been a series of changes in the educational structure. Initially, the program was three
years long. Over the years, many distinguished physicians were trained within its walls, one
of the most renowned being Dr. Francisco Javier Eugenio de Santacruz y Espejo. A native of
Quito, he was highly regarded for his fight against the marginalization of historically
excluded social groups, his critique of the university system, and his scientific contributions
to Ecuador's health regulations at that time (Estevez, 2018, p. 151).
In recent history, amidst political and ideological struggles, the Faculty of Medicine
continues to train professionals in medicine and surgery. The Faculty of Medical Sciences
has experienced “changes in the educational systems themselves and in social, economic,
productive, ecological, political, cultural, scientific, technological, philosophical, and human
structures” (Barros et al., 2018, pp. 77–78). Estevez et al. recount that the teaching of basic
medical subjects such as anatomy was based on the direct observation of dissected cadavers
in the anatomy theater. In these classrooms, at least one hundred students received lectures
from a single professor. For clinical subjects, bedside teaching remained the foundation;
moreover, the correct execution of the medical history was paramount. Amidst disputes
regarding its proper preparation, an important bibliographic work was established at the
Faculty: the Medical Examination, by Dr. Carlos Guarderas in 1982 (Estevez et al., 2018, p.
151).
2.2.2 Pedagogical models used in current medical teachingl
Medical education is one of the settings where the pedagogical models contained within the
hetero-structuring approach are commonly applied. Medical schools, such as the one
mentioned earlier, use both the chalk talk model and the slide projection model for lectures.
However, the effectiveness of these methods in teaching basic biomedical sciences, such as
immunology, is still a subject of debate.
Saca and Tituaña conducted a cross-sectional analytical epidemiological study between
2016 and 2017 at the Faculty of Medical Sciences of the Central University of Ecuador,
regarding the pedagogical models used by nursing faculty. They found that 50% of faculty
members who teach rotating internships consider memorization of concepts important.
Meanwhile, 50% of students did not fully understand the lectures, citing some problem with
content retention and comprehension (Saca & Tituaña, 2017). This finding highlights the
need for further investigation into the efficacy and effectiveness of different pedagogical
methods in biomedical science education and their relevance to student learning.
In addition to considering the lecture-based methodologies employed, Reyes et al. analyze
the students' sex and IQ range as moderating variables. According to a 2019 study by the
Eloy Alfaro Lay University of Manabí, both men and women have a reflective learning style.
However, individual differences may exist between the two genders, modifying their
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learning styles. It was observed that women are more active and practical in completing
tasks, which may lead to higher scores on academic assessments. The study also found that
women may be more skilled in perceptual speed, verbal fluency tests, manual dexterity, and
mathematical calculation; while men perform better in spatial tasks, motor skills, and
mathematical reasoning. However, it is worth clarifying that there are not enough studies
to demonstrate that one sex has a greater learning capacity than the other (Reyes et al.,
2019, pp. 48–50).
Similarly, intelligence quotient (IQ) could affect or influence the learning process. Aravena
et al., in an analytical cross-sectional epidemiological study, concluded that, as an
assessment of multiple domains, IQ is understood to influence the teaching-learning process
depending on the approach and model used. This is why this and other studies have shown
that in cases of moderate IQ deficiency, academic performance decreases, while with a
normal or average IQ, there are no significant differences between individuals (Aravena et
al., 2017).
3. Materials and methods
A quasi-experimental operational study with a non-equivalent control group was conducted
to compare two pedagogical methods for teaching basic immunology to first-semester
medical students at the Faculty of Medical Sciences of a public university in Ecuador. Four
of the eight parallel sections of first-semester students were randomly selected for the
study. The implications of participating in the project were explained to the students
beforehand, so that they could voluntarily sign informed consent forms, along with
providing basic information required for identification within the study. Participants were
students over 18 years of age, enrolled in the first semester of medicine, with regular class
attendance, who agreed to participate in the study and receive the educational intervention.
Those who did not complete the pre-intervention and post-intervention questionnaires, did
not attend the class (intervention), or had previously taken the course were excluded.
Participant information was collected in person using printed forms.
In addition to the identification data according to Wang et al., the survey technique was
applied to estimate IQ range using a psychometric test, Raven's Progressive Matrices Test,
which measures educational intellectual reasoning ability; that is, reasoning, planning,
cognitive flexibility, decision-making, abstraction, and complex problem-solving. Based on
this, it estimates an individual's IQ range on a scale from Range I (Superior) to Range V
(Poor) (Wang et al., 2019, p. 6441). It does not represent overall intelligence quotient and
was administered using each participant's mobile device.
The sample size was estimated using a statistical calculation for two proportions based on
an estimated difference in effectiveness of 0.60 versus 0.30 between the interventions. The
study by Petimani was used as a reference, resulting in a minimum of 50 participants per
group to ensure statistical significance (Petimani & Adake, 2015, p. 292). Based on this
criterion, two of the four sections were randomly assigned to the experimental group (chalk
talk class) and the remaining two to the control group (slides class).
The intervention, implemented during the 2014-2015 academic period, was delivered by
the same instructor to both groups. Each session lasted 50 minutes and included an
introduction to the topic, objectives, lesson development, and questions. Each group
underwent three assessments: before the intervention, immediately after, and one week
later, with strict monitoring to prevent cheating on the tests. Knowledge tests validated by
the histoimmunology department of the same institution were used to estimate the level of
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knowledge. Each test consisted of 10 multiple-choice questions, each with 5 options, only
one of which was correct. The study adopts a quantitative approach.
A traditional pedagogical model, similar to lectures, was implemented with two variations:
one using chalk talk techniques and the other using slide presentations. During the chalk
talk intervention, the instructor used only an enameled steel whiteboard (1.20 x 2.40 m)
and dry-erase markers; no images were projected. In contrast, the control group received
PowerPoint slides, limited to a maximum of seven lines of text per slide and without
animations; these were projected on a 100 x 56 in image by an Epson S18+ projector. The
intervention took place in a classroom with a capacity of 100 people, with tiered seating at
an average distance of 5 meters from the presentation.
The data were managed in both physical and electronic formats, collected using
questionnaires printed on A5 bond paper with text in 12-point Arial font, and analyzed
using Microsoft Excel and SPSS version 18.0.0. The results were anonymized with
alphanumeric codes. The statistical analysis included the description of the qualitative
variables sex and intellectual range (IQ) using absolute frequency, relative frequency, and
the respective 95% confidence interval; Student's t-test for differences of proportions
between independent groups was used to compare these data. To compare the learning
level before, after, and one week after the intervention, for each study group, the scores
were compared using medians, ranges, and respective 95% confidence intervals; and, for
the pre-post inferential analysis in the same group, the Friedmann test was used.
For the intergroup analysis, means, standard deviations, and respective 95% confidence
intervals were used. For inferential analysis, Student's t-test for the difference of means
between independent groups with homogeneous variance was used. Results were
compared before, after, and one week after the interventions, after the Kolmogorov-
Smirnov test had been used to determine data normality. To compare the results of the two
groups (experimental and control) and to verify the intervention's effect on the moderating
variables of sex and IQ score, the Mann-Whitney U test was used, following the same
comparison logic described above. Results were considered statistically significant as long
as p ≤ 0.05.
Population N=315
Sample required n=50
Excluded n = 50
Minimum number of participants required = 110
Participants n = 164
Sampling at two proportions
for each group
Through a physical, in-person survey
Participants included n = 114
(+10 % probability of loss)
Figure 1. Sampling and allocation of study participants
Control
n=60
Experimental
n=54
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The study complies with the ethical principles of the Declaration of Helsinki and the
Nuremberg Code, guaranteeing the confidentiality of information and obtaining informed
consent from participants. The study was conducted in accordance with current legislation
and regulations.
4. Results
Of the 164 participants included in the study, 50 met one or more exclusion criteria, leaving
114 who completed all phases of the study. Of these, 54 were in the experimental group and
60 in the control group, as shown in Figure 1. These participants received the intervention
in their assigned group, were assessed at three time points, and provided complete
information.
The experimental group (n=54) consisted of 17 men (31.5%; 95% CI: 20.7-44.7%) and 37
women (68.5%; 95% CI: 55.3-79.3%) [p>0.05]. 28 (51.9%; 95% CI: 38.9-64.6%) were part
of Intellectual Range I and II, and 26 (48.1%; 95% CI: 35.4-61.1%) were in range III, IV and
V [p>0.05]. Meanwhile, the control group (n=60) consisted of 17 men (28.3%; 95% CI: 18.5-
40.8%) and 43 women (71.7%; 95% CI: 59.2-81.5%) [p>0.05]; 41 (68.3%; 95% CI: 55.8%-
78.7%) were in Intellectual Range I and II, and 19 (31.7%; 95% CI: 21.3%-44.2%) were in
Range III, IV, and V [p>0.05]. These data are presented in Table 1.
In the experimental group (chalk talk), scores out of 20 were measured pre-intervention
(O1), post-intervention (O2), and one week later (O3); all these measures are presented in
Table 2. The mean O1 score was found to be 5.07 ± 2.77 (95% CI: 4.34-5.81), and the mean
O2 score was 12.93 ± 3.86 (95% CI: 11.90-13.96). and the mean O3 score was 8.33 ± 3.68,
95% CI: 7.35–9.32.
In the control group (slide presentation), scores out of 20 were measured pre-intervention
O4, post-intervention O5, and one week later O6; all these measures are shown in Table 3.
The mean O4 score was found to be 6.07 ± 3.29, 95% CI: 5.23–6.90; the mean O5 score was
8.77 ± 3.19, 95% CI: 7.96–9.57; and the mean O6 score was 6.93 ± 3.58, 95% CI: 6.03–7.84.
Moderating variables
Chalk talk
Slides
p
N
54
60
Gender
Men
17 (31.5 %)
17 (28.3 %)
0.719
Women
37 (68.5 %)
43 (71.7 %)
0.719
IQ Range
I-II
28 (51.9 %)
41 (68.3 %)
0.072
III-IV-V
26 (48.1 %)
19 (31.7 %)
0.072
Table 1. Comparison of sex and IQ range between chalk talk group and slides
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In the statistical analysis of scores between interventions, no statistically significant
difference was found between the means O1 and O4 (p>0.05). However, a statistically
significant difference was found between the means O2 and O5 (p<0.05); and one week
later, the means between O3 and O6 remained statistically different (p<0.05). The
aforementioned means and their 95% confidence intervals are shown in Figure 2. All these
results assume that the data were not broken down by sex or age.
Chalk Talk
O1
O2
O3
N
54
54
54
Average
5.07
12.93
8.33
DE
2.77
3.86
3.68
EEM
0.38
0.53
0.50
Minimum Value
0
6
2
Maximum Value
12
20
18
Lower Limit
4.34
11.90
7.35
Upper Limit
5.81
13.96
9.32
Table 2. Test results of the experimental group experimental0
Slides
O4
O5
O6
n
60
60
60
Average
6.07
8.77
6.93
DE
3.29
3.19
3.58
EEM
0.43
0.41
0.46
Minimum Value
0
2
0
Maximum Value
12
16
16
Lower Limit
5.23
7.96
6.03
Upper Limit
6.90
9.57
7.84
Table 3. Test results of the control group
Figure 2. Averages of the six observations (O1-O6), with their 95% CI
IC95 %
DATOS
INTERVENTION
PRE-INTERVENTION
POST-INTERVENTION
POST-INTERVENTION
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Observations O2 and O5, conducted only on men, indicate that the medians are different
(p<0.05), as do the medians of observations O2 and O5 in women (p<0.05). Observations
O2 and O5, conducted only on individuals with IQ Ranks I and II, indicate that the medians
are statistically different (p<0.05). Similarly, the medians of O2 and O5, conducted only on
those with IQ Ranks III, IV, and V, are also statistically different (p<0.05).
5. Discussion and conclusions
This study aimed to determine the effectiveness and efficiency of chalk talk and slide
presentations in basic biomedical sciences. The collected data indicate a statistically
significant superiority of chalk talk over standard slide presentations. These findings align
with those of Asian Diphu University in 2021; as noted by Putul, medical students in the
microbiology department reported a better learning experience with chalk talk (97%)
compared to PowerPoint (86%) (Putul et al., 2021, p. 471). However, Lagare et al. point out
data from a descriptive study conducted at Sankalchand Patel University in 2023, in which
54% of students reported a better academic experience with slide presentations compared
to 46% who preferred the blackboard. It should be noted that, in this case, the presenters
were not faculty members, but students during a pharmacology seminar (Lagare et al., 2023,
p. 856).
On the other hand, Brown et al. state that the control material used in this study was
inanimate; the differences may be partly explained by this lack of animation. This is based
on the results of a study conducted by Brown in 2022 at the University of Hawaii School of
Medicine, USA, which demonstrated that virtual animations in teaching medical residents
were superior to chalk in learning pharmacological therapy for diabetes (Brown et al., 2022,
p. 2256). It is also possible that the observed differences depend not only on the overall
teaching format but also on the interactivity the methodology allows: students who actively
interact with the material (discussing cases, answering questions, working in teams) retain
and apply the content better than those who receive a passive lecture. In a randomized
crossover trial with 146 medical students, Boedeker et al. showed that the large group
session conducted as an interactive activity resulted in higher learning scores (p = 0.010)
and a greater “sense of learning” (p < 0.001) compared to the passive lecture; furthermore,
students with lower prior performance benefited from the interactive modality (Boedeker
et al., 2024).
Another point to consider from Jabben and Ghani's perspective is the type of information to
be conveyed to students; immunology and microscopic sciences are areas of study that
differ from areas such as macroscopic anatomy. In these cases, the use of images via slide
projection is more viable, as postulated by Jabeen from the Department of Anatomy and
Orthopedics at the Faculty of Medicine of the University of Jammu, Asia (Jabeen & Ghani,
2015).
The chalk talk method shows effectiveness in the short- and medium-term teaching process
for medical students; while the slide projection method shows effectiveness in the short
term, but not in the medium term. In terms of efficacy, the chalk talk methodology
demonstrates superiority over the slide projection methodology in both the short and
medium term. The results are not influenced by the student's IQ range or gender. The
academic community is recommended to consider the data presented in this study for the
modification, or if necessary, ratification, of their teaching and pedagogical plans.
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Authors
WASHINGTON PAZ-CEVALLOS: Bachelor of Science in Education from the Central
University of Ecuador (1999). Doctor of Medicine and Surgery from the Central University
of Ecuador (1986). Master of Science in Health Research and Administration from the
Central University of Ecuador (1997). Diploma in Systematic Reviews and Meta-Analyses
from the Italian University Institute and Hospital of Buenos Aires (2021). Diploma in
Statistics for Health Sciences from the University of the Hemispheres (2018). Diploma in
Research and Biostatistics from SINCIE (2015). Postgraduate Diploma in Health Sciences
Education from the Central University of Ecuador (2006).
He is currently an undergraduate professor in the Medicine and Obstetrics programs, as
well as in clinical and surgical postgraduate programs, master's programs, and Research
Methods 1 and 2. He is a thesis advisor for the Nursing program and clinical and surgical
postgraduate programs. Former Head of the Research Department. Former President of the
Ethics Committee of the Faculty of Medical Sciences at the Central University of Ecuador.
MARCOS JIMÉNEZ-CÓRDOVA: obtained his Bachelor of Science degree, awarded by the
Ministry of Education of Ecuador through the San Francisco de Asís Educational Unit, in the
canton of Balsas, El Oro province, Ecuador, in 2020. He was the top graduate of his class.
He is recognized by the Secretariat of Higher Education, Science, Technology and Innovation
as a student in the National High-Performance Group. He is currently a rotating medical
intern at the Quito Specialty Hospital No. 1 of the National Police while a student at the
Faculty of Medical Sciences of the Central University of Ecuador.
MARY ORDÓÑEZ-ASANZA: obtained her Technical High School Diploma in Computer
Applications Services, awarded by the Ministry of Education of Ecuador through the Jambelí
High School, in the canton of Santa Rosa, El Oro province, Ecuador, in 2020. She was the top
graduate of her class.
He is recognized by the Secretariat of Higher Education, Science, Technology and Innovation
as a student in the National High School System. Endorsed by the Secretariat of Higher
Education, Science, Technology and Innovation as a student in the National High-
Performance Group. She is currently a rotating medical intern at the Quito Specialty
Hospital No. 1 of the National Police, while a student in the Faculty of Medical Sciences at
the Central University of Ecuador.
TERESA HARO-BLACIO: obtained her Bachelor of Science degree, awarded by the Ministry
of Education of Ecuador through the Jorge Chiriboga Guerrero Educational Unit, in the
canton of La Concordia, Santo Domingo province, Ecuador, in 2020. She was the top
graduate of her class.
She is currently a rotating medical intern at the Quito Specialty Hospital No. 1 of the National
Police, while a student in the Faculty of Medical Sciences at the Central University of
Ecuador.
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Declaration of authorship-CRediT
WASHINGTON PAZ-CEVALLOS: Formal analysis, research, methodology, project
management, software, supervision, writing – revision and editing.
MARCOS JIMÉNEZ-CÓRDOVA: Conceptualization, data curation, formal analysis,
validation, writing – original draft, writing – revision and editing.
MARY ORDÓÑEZ-ASANZA: Conceptualization, data curation, validation, writing – original
draft, writing – revision and editing.
TERESA HARO-BLACIO: Conceptualization, data curation, validation, writing – original
draft, writing – revision and editing.
Declaration of the use of artificial intelligence
The authors declare that they did not use Artificial Intelligence (AI) tools for any part of the
manuscript. No part of the scientific content, results, analyses, or interpretations was
generated by artificial intelligence. All material was reviewed and validated by the authors,
who are responsible for its accuracy and rigor.
