Desafíos para el trabajo práctico en la educación en ciencias: resultados de una revisión sistemática de la literatura

Purpose of Practical Work in Science Education

Although there is no universally accepted definition for the concept of practical work, it is widely acknowledged by educators and researchers in science education that the practical applications of scientific concepts play a crucial role in enhancing student learning in this field (Herschbach, 2014). This emphasis on practical work became particularly prominent the 1960s and has remained integral to science education ever since. Over this historical period, practical work has come to be viewed as a foundational and essential component of science education. Research findings have consistently highlighted its benefits in teaching and learning, particularly in fostering meaningful learning, as demonstrated by Ausubel (2000).

Hodson (1993) further categorized the objectives of practical work into five broad areas: 1) Motivation, which involves stimulating interest and enjoyment; 2) Teaching laboratory techniques; 3) Enhancing the learning of scientific knowledge; 4) Promoting an understanding of the scientific method and competence in its use; and 5) Developing scientific attitudes, such as objectivity.

Additionally, Hodson emphasized that beyond learning scientific facts and concepts, it is also essential for students to engage in "doing" science—solving problems that are relevant to them in a context where the teacher serves as a facilitator, in line with a constructivist approach.

However, it is important for students to recognize that scientific practice is a complex and socially constructed activity. This awareness cannot be fully achieved solely through carrying out personal investigations on topics of individual interest.

More recently, the Gatsby Foundation's Good Practical Science Report (Holman, 2017) identified five purposes of practical work in science education, each intrinsically tied to its benefits: 1) Teaching the principles of scientific investigation; 2) Improving understanding of theory through practical experiences; 3) Developing practical skills, such as measurement and observation, that may be useful for use in future studies and/or employment; 4) Motivating and engaging students; and 5) Cultivating highlevel skills and attributes such as communication, teamwork, and perseverance.

The Challenges of Practical Work in Science Education

Over time, several challenges have been identified in the implementation of practical work in science education, particularly in relation to the pedagogical training of teachers and educators. Regarding this issue, Yager and Lunetta (1984) outlined eight key areas for intervention in science teacher training: 1) Providing experiences with problems and social issues related to science; 2) Developing practices in decisionmaking strategies; 3) Raising awareness about professional careers in the scientific field; 4) Promoting local involvement and community relevance; 5) Creating practical applications for the abstract concepts of pure science; 6) Focusing on cooperative work on real, current problems; 7) Emphasizing the multiple dimensions of science, such as historical, sociological, and philosophical perspectives; and 8) Assessing students based on their ability to obtain and use available information.

From the perspective of in-service science teachers, a study by de Aiello (2004) found that teachers place a strong emphasis on classroom activities in which students actively engage with real-world phenomena or problems, often through group discussions and small-group investigations. However, Molina et al. (2009) highlighted that teachers still need to move beyond a narrow focus on epistemology and didactic methods toward more contextual approaches, particularly regarding cultural diversity and its implications for science education.

To enhace the effectiveness of practical work, Abrahams and Reiss (2017) advocate for a model that encourages students to reflect not only on the procedures they perform but also on what they are learning from these practical activities. Subsequently, Hofstein (2017) noted that one of the greatest challenges in practical work is shifting away from the traditional emphasis on manipulating equipment rather than exploring ideas. He suggested that the experimental teaching commonly conducted in school laboratories tends to prioritize “hands-on” approaches over “minds-on” approaches, which can hinder deeper intellectual engagement. This issue is often linked to teachers’ concern about losing control in the classroom, as encouraging students to take more responsibility for their learning can create a less predictable classroom environment.

Tamayo et al. (2019), also identified a weak correlation between the development of cognitive knowledge and metacognitive skills, highlighting the need to foster both aspects from an early age in order to support students’ understanding of scientific concepts.

Acknowledging the limitations and challenges associated with practical work in science education, Sharpe and Abrahams (2020a) emphasize the importance of considering the affective value of practical work. Specifically, they advocate for a deeper understanding of how students form their attitudes and the factors that influence them, to better optimize learning experiences in scientific disciplines.

1.3 - The Purpose of the Investigation

Given the issues previously discussed, the relevance and the urgency of identifying the current state of the art concerning the advantages and disadvantages of practical work in science education become clear. This investigation focuses specifically on secondary education level, which the International Standard Classification of Education defines as beginning between the ages of 10 and 13, and ending between the ages of 17 and 18, in most countries (UNESCO Institute for Statistics, 2012).

To achieve this goal, a systematic literature review was designed and conducted, following the PRISMA guidelines (Page et al., 2021). This approach promotes transparency in the analysis process by adhering to a welldocumented, standardized method, enabling the inclusion of a more comprehensive and diverse selection of manuscripts on the topic (Gazley, 2022). Additionally, a significant benefit of systematic literature reviews is their ability to minimize biases that may arise from the subjective interpretations of individual authors (Clark et al., 2021).

In summary, this investigation aims to reveal the current understanding of the advantages and the disadvantages of practical work in science education, as perceived by students, science teachers, educators, and researchers.

2.1 Research question

The investigation began with the formulation of a guiding research question, using the spider tool—Sample, Phenomenon of Interest; Design, Evaluation, Research type— which is particularly well-suited for qualitative research (Cooke et al., 2012). The sample consisted of pre-university educational institutions, while the phenomenon of interest was the implementation of practical work in science teaching. A qualitative approach was chosen for the design, which was realized through a systematic review of the literature. The evaluation focused on determining the current state of the art on the implementation of practical work in pre-university science education. Finally, the research type included studies using quantitative, qualitative, and mixed-methods methodologies.

With the support of the spider tool, the research question was formulated as follows: What is the current state of the art on practical work in science teaching at the pre-university education level?

2.2 Data sources, search engines and key words

Based on the research question, the following keywords were selected: practical work, science education, and secondary schools. Combining these keywords with Boolean operators allowed for the creation of search strings to be used in various databases.

Four major databases were chosen for the research: eric, Google Scholar, Scopus, and Web of Science. In addition, a Portuguese database aggregator, B-on, was included. Table 1 shows the number of manuscripts initially retrieved from each of these sources after applying the search strings.

Table 1.: Results of the first identification of studies for the constitution of the corpus (Oliveira & Bonito, 2023

Note: Own elaboration

2.3 Synthesis of Results and Quality Assessment

An initial total of 163 studies of potential interest were retrieved from the selected databases. After removing duplicate entries (n=14), 149 publications remained for the screening phase. During this phase, manuscripts were excluded based on the relevance of their titles (n=20) and abstracts (n=10), leaving 119 manuscripts for further assessment according to the eligibility criteria.

Among these 119 publications, some were excluded because they were inaccessible (n=13), others were final master's or undergraduate dissertations (n=3), and others fell outside the scope of the research upon full-text analysis (n= 50). Consequently, the final research corpus consisted of 53 studies. This entire process is illustrated in the diagram in Figure 1.

Figure 1: Identification, screening and inclusion diagram of the manuscripts in the corpus under study (Oliveira & Bonito, 2023)

Note: Own elaboration. - Results and Discussion

As mentioned previously, the systematic literature review resulted in a research corpus comprising 53 international studies, which are listed in Table 2.

Table 2: Studies included in the constitution of the corpus

The analysis of the corpus reveals that most of the studies used a qualitative research approach (n=31; 58.5%), followed by quantitative studies (n=18; 34.0%), and finally, studies that adopted a mixed-method approach (n=4; 7.5%) (see Table 3).

Table 3.: Corpus organization by research methodology (Oliveira & Bonito, 2023)

Note: Own elaboration

Advantages of practical work

The content analysis of the studies in the corpus identified five overarching categories of advantages associated with the promotion of practical work (Table 4).

Table 4.: Identified advantages in practical work (Oliveira & Bonito, 2023)

Note: Own elaboratio

In the first research category (n= 37; 69.8%), practical work is recognized as a means to develop learning skills grounded in research processes (S1, S4S7, S11-S21, S24, S27-S30, S32, S34-S36, S38, S40-S45, S47, S50-S53). More specifically, incorporating practical work into science education can make content more relevant to students, enhancing their motivation, fostering the excitement of discovery, and promoting positive attitudes toward science. Additionally, it has the potential to increase students’ intrinsic motivation. Similarly, engaging in learning activities outside the classroom and conducting on-site investigations of objects, tools, cases, and events that cannot be directly brought into the school environment are highlighted as major advantages. As Mkimbili and Ødegaard (2019) illustrate:

when students are involved in the investigations by using context-relevant materials, they can attain meaningful learning as they link science from the classroom to the real world. Out-of-school learning resources can be beneficial also for wellresourced schools, as they provide more authentic learning contexts (…)” (p. 1840).

Furthermore, practical work is viewed as essential for capturing and maintaining students' interest in science, encouraging them pursue further studies in this field (S1, S6, S12, S14, S16, S20, S24, S28, S29, S34, S38, S43, S44, S51, S52). Many teachers see practical work as a crucial element of everyday science education practice, fundamental for effective learning. It enables the development of transferable skills, such as prediction, observation, and interpretation, and provides teacher with immediate feedback. This promotes an active and in-depth approach to learning, rooted in real-world problems. As Sund (2016) argues, developing scientific process skills should be one of the primary goals of science education: “not just in terms of preparing future scientists to ‘do’ science, but to equip people to be ‘scientifically literate’, so that they are able to make scientifically informed decisions in their everyday lives about global issues” (p. 2222). Finaly, another key advantage noted in this category is its ability of practical work to enhance collaborative learning dynamics.

Another group of studies (n= 36; 67.9%) identifies the active participation of students in the learning process as a key advantage of practical work (S1, S3-S10, S12, S16, S17, S19-S21, S23; S26 -S31, S34, S36, S37, S41-S47, S49S51, S53). Conversations about learning activities during practical work are especially valuable for developing communication skills. Additionally, practical work helps students build foundational practical skills and motivates them to pursue scientific careers by boosting their confidence to study these areas at more advanced levels.

Furthermore, engaging in practical work enhances students' ability to construct mental models of scientific phenomena that cannot be directly observed and has a significant impact on their emerging professional identities, as well as on the value frameworks of future science teachers. Another notable advantage is that practical work often leads to more effective learning, as students are more likely to understand and remember actions they performed themselves. Babalola et al. (2020) emphasize this point:

In countries with a long tradition of laboratory-based science teaching at school level, practical work is seen by many teachers as an essential aspect of their everyday practice. It is often claimed that practical work leads to better learning in that we are more likely to understand and remember things that we have done rather than things we have merely been told. (p. 260)

Practical work involves students in scientific topics, building their knowledge, hands-on practical skills, and conceptual understanding (“mindson”) while encouraging them to construct their own knowledge from a constructivist perspective. This approach is highlighted in 30 studies (56.6%) - (S1, S2, S4, S6, S9-S12, S16, S19, S20, S24, S25, S27, S28, S30; S33-S36, S38, S40, S43-S48, S51, S52). Ruparanganda et al. (2013) illustrate this idea in the context of biology education:

Practical work is an inquiry and hands on activity which makes it possible to transfer knowledge on higher order cognitive levels and create curiosity in students. Practical work develops problem solving skills and a deeper understanding of the concepts and principles in Biology for students. (…) Students, through doing practical work, would be doing what real scientists do and they would appreciate that theories are generated from research. Doing practical work forms the basis for good research skills in students. (p. 14)

Practical work, particularly in laboratory settings, also helps students understand the difference between observation and data presentation. This methodology supports students' learning processes and motivates their engagement while aligning with the specific curricular requirements of scientific disciplines. In this category, practical work is also seen as instrumental in improving science teachers' knowledge and professional practice.

For another subset of authors (n=21; 39.6%), practical work emerges as a central strategy for developing scientific literacy (S3, S7-S9, S12-S14, S22, S23, S27-S29, S34, S38, S40, S42; S44-S46, S48, S50). Studies in this category emphasize the understanding of processes and concepts. Practical work helps to diagnose and address students' misconceptions, stimulates their curiosity about physical and natural phenomena, and contributes to their social development. Additionally, learning about the nature of science and developing critical and creative thinking are highlighted as essential benefits of practical work. Musasia et al. (2012) emphasize this in the context of physics education:

If practiced in the right manner from the early secondary school period, critical thinking skills can be attained from practical work in physics. Practical work puts the students at the center of learning where they can participate in, rather be told about physics. In this way the desire and eagerness to know more about what the subject can offer is developed. (p. 153)

Finally, a small group of studies (n=4; 7.5%) highlights the role of practical work in preparing students practical assessments (S1, S14, S44, S46).

Disadvantages of Practical Work

The content analysis of the studies identified five broad categories of disadvantages associated with the promotion of practical work (see Table 5).

Table 5. : Identified disadvantages in practical work (Oliveira & Bonito, 2023)

Note: Own elaboration

In the first category, which accounts for 49.1% (n=26) of the studies, disadvantages related to teachers' concerns about implementing practical work are highlighted, including issues with professional content knowledge (S1, S2, S4, S8, S10, S12, S17; S18, S23, S24, S26-S28, S31, S32, S34, S36, S38, S40, S41, S44, S46, S47, S50-S52). This focus on pedagogical content knowledge (PCK) is illustrated by Wei et al. (2019):

However, most of the courses of PGCE offered in local universities involve general pedagogy rather than subject-based pedagogy let alone the pedagogy of practical work. In most cases, practical work-related courses are not offered in Master-degree programs either, such as Curriculum and Instruction in the Faculty of Education, University of Macau. This might be the reason that science teachers did not attribute the development of their PCK of teaching with practical work to in-service training program. (p. 735)

Similarly, teachers expressed concerns about maximizing the effectiveness of practical work, managing classroom activities, collaborating with colleagues, and refining tasks—all with the goal of developing of students' skills in mind.

On the other hand, there is a concern that teachers may view practical work as a universal solution for all educational challenges. In some cases, teachers lack the skills to effectively guide students through practical work, partly because teacher training and disciplinary curricula have not sufficiently emphasized the importance of clarifying the meanings of terms and concepts during its implementation. The use of language for effective communication in the classroom, as a pedagogical skill, is often not emphasized enough in the initial training of science teachers or in their professional development programs, this gap is reflected in both the frequency and quality of practical work activities. In addition, cultural factors impact how well-prepared students and teachers are within their zone of proximal development to adopt inquiry-based learning practices.

To sum up, enhancing competence in data analysis has rarely been a central objective of practical work, which limits the potential learning outcomes. Another concern in this category is a significant misalignment between the intended curriculum and the one that is actually implemented. A shift toward a more student-centered curriculum, as opposed to one centered on teacher actions, is also recommended.

Other studies (n=36; 39.6%) identify the distortion of practical work's purpose due to assessment pressures as a disadvantage (S2, S3, S6, S7-S10, S13, S16, S22, S25, S27, S34, S36, S39, S42, S45, S47, S48, S52, S53). Students often focus primarily on completing tasks for assessment purposes, which can drastically limit the potential for meaningful learning. Approaches to practical work are sometimes viewed as impractical within the constraints of assessment, particularly given congested curricula and the time required to develop effective evaluation systems, as demonstrated by Ye et al. (2021):

According to the results of experts’ weight assignment of teaching competencies of science teacher, science teachers in China do not attach great importance to individual science learning evaluation, and especially to its core competences such as the evaluation of students’ practical work and their feedback. The biggest challenge in evaluating science learning is the cost (such as time, intelligence, labor, etc.) involved in designing and developing the evaluation. (p. 402)

With regard to laboratory work, assessment rarely focuses on actual practical performance and is primarily based on written tests. High-stakes assessments —such as national exams—often distort how practical work is used to facilitate teaching and learning in science lessons. For assessment to be effective, it should consider conceptual understanding, procedural understanding, and also procedural or practical skills (although these terms are rarely defined explicitly). The availability of alternatives to practical tests in science education also means that students can complete exams without ever engaging in practical work. As a result, students may be less equipped to apply their knowledge to solve real-world problems in their daily lives.

In a third category (n=20; 37.7%), studies highlight limitations due to economic, organizational and, environmental constraints (S1, S4, S14, S21, S29, S34, S36, S38, S40-S45, S47- S51, S53). Implementing practical work requires facilities with up-to-date equipment and adequate space for effective participation in practical investigations (e.g., laboratories). This requirement makes the promotion of practical work less common in countries with limited economic resources, where there is constant pressure to justify the continued inclusion of practical work, especially in a period in which greater efficiency in resource management is demanded. Tesfamariam et al. (2014) illustrate this issue:

Furthermore, practical work requires more time and the presence of qualified and experienced teachers and technical assistants. As a result, it is frequently missed from the real curriculum in schools around the world (…) amongst the reasons mentioned are: absence of laboratory room, lack of equipment and chemicals, shortage of time, large workload, absence of laboratory technical assistants, fear of chemical hazards, teachers feeling inadequately prepared, lack of laboratory manuals, lack of basic facilities such as water or electricity, and large class size. It can also be argued that the problem has been worsened by the recently observed fast- growing student population in the sciences not being matched with resources. (p. 51)

For this reason, funding restrictions are identified as a restrictive factor, which can ultimately prevent teachers from carrying out practical work. This situation may contribute to a persistent lack of interest in scientific courses and related professional careers. The infrequent use of training activities outside the classroom may derive from the common belief that knowledge can be acquired just as effectively within the classroom, where lessons are traditionally organized by teachers and students. Experiences outside school are often considered unimportant, and field trips present several limitations, such as time-consuming planning, limited budgets for transportation and accommodations, large class sizes, disruptions to the curriculum, and weather-related uncertainties when exploring outdoor spaces.

Inquiry-based learning also rarely occurs in school environments that are rigidly structured, making it difficult for students to engage in open-ended investigations. Since these investigations typically involve a degree of uncertainty and unpredictability, the classroom is often not well-suited to support them. In addition, teachers are burdened with extensive administrative work related to assessment processes, which limits their time and discourages them from involving students in open investigations. Large class sizes also raise concerns, especially in Chemistry classes, where the risk of chemical hazards and environmental pollution must be managed.

Another group of studies (n=18; 34.0%) identifies limitations associated with the nature of learning tasks, which are often overly descriptive and follow a “cookbook” style (S2, S4, S6-S8, S11, S15, S17-S19, S25, S26, S30, S33, S37, S39, S46, S52). This concept is described by Erduran et al. (2020):

In examining what is typically taught with respect to practical science exposes that students are engaged in procedures that do not make sense from their points of view. Mindless pursuit of procedures has typically been referred to as the ‘cookbook problem’. (p. 1545)

Students may become frustrated in inquiry-based learning environments and may not achieve a greater conceptual understanding compared to direct instruction. In certain situations, practical work may be more effective at ensuring students perform specific tasks set by the teacher through the manipulation of physical objects, rather than allowing them to apply scientific ideas and reflect on data. This limitation can reduce opportunities for creativity and critical thinking, making practical work counterproductive and potentially a waste of time without yielding significant learning outcomes. Furthermore, this approach has been criticized for not aligning with how scientists actually work, as it is increasingly recognized that scientific processes cannot be separated from scientific ideas.

Lastly, a small group of studies identifies limitations associated with the motivational effects of practical work on students (n=3; 5.7%) - (S1, S20, S43). In this category, the contributions of practical work to the acquisition of professional and personal skills are sometimes minimal, providing insufficient motivation for students. It is also pointed out that students may prefer practical work and group activities only as an alternative to more theoretical teaching strategies. If not executed effectively, practical work can become a source of stress or anxiety, potentially neutralizing its educational benefits, as it was described by Wilson (2018):

A number of students reported that Labdog placed excessive demands on their time and attention during the laboratory. SFY students were required to simultaneously complete the practical in Labdog, fill out their lab notebooks and submit post-lab coursework. This caused a number of students to identify Labdog as a cause of stress or anxiety, which could counteract or prevent the educational benefits.

Furthermore, there were ongoing complains regarding technological problems. (p. 196)

- The Advantages of Practical Work

The analysis of results indicates that while the adoption of practical work in science teaching presents several challenges, it also offers several opportunities. Starting with the benefits, the primary advantage of practical work appears to be its ability to develop students' practical skills in scientific processes, alongside a fundamental conceptual understanding. This is achieved through a fusion of “hands-on” and "minds-on" approaches, which together enhance motivation for learning science and increase the likelihood of more students will pursue scientific careers. This potential increase in the number of future scientists could positively address the shortage of human resources currently experienced in certain contexts.

The second prominent advantage is that researchers consider this methodology essential for the development of students' scientific literacy, significantly improving their understanding of concepts related to scientific phenomena. In this regard, practical work contributes to the important mission of countering misconceptions, unsupported beliefs, and alternative conceptions, thereby helping to cultivate well-informed individuals with critical thinking skills.

The third major advantage of practical work is its role in developing research skills, allowing students to engage in processes similar to those used by scientists. This immersion fosters a deeper understanding of the nature of scientific inquiry and the daily tasks involved in a scientific career.

- The Disadvantages/Challenges of Practical Work

Throughout this investigation, several challenges associated with practical work were identified, primarly related to the strategies employed. Without proper guidance, practical work can easily devolve into a routine of merely describing observations and actions, resulting in activities that are excessively descriptive and follow a “cookbook” workbook, which does not align with how scientists carry out their work.

A second challenge is the difficulty of conducting practical work in countries and contexts with limited economic resources. Financial constraints directly affect the availability of well-trained human resources and the creation of appropriate spaces and infrastructure, such as laboratories and informal science education centers. These constraints also hinder the acquisition of necessary materials to equip these spaces properly and limit opportunities to transport students to environments outside the classroom.

Effective practical work, particularly open-ended investigations, requires adequate facilities and manageable class sizes—conditions that are not present in many schools. Additionally, the time and workload associated with assessing these activities pose another challenge, which can sometimes discourage both students and teachers. Finally, students often focus on completing practical work according to perceived expectations, following protocols and meeting teacher requirements, which can obstruct genuine learning opportunities and distort the primary objectives of practical work.

Given the challenges highlighted by this systematic literature review, future research should explore ways to transform these obstacles into new opportunities for science education. Broadly, the challenges of practical work identified by this review can be grouped into four key areas: 1) selected strategies; 2) issues related to limited economic resources; 3) the need for adapted classrooms and adequate spaces; and 4) time constraints.

As a recommendation for the first area, more emphasis should be placed on initial and ongoing teacher training programmes to help science teachers develop their pck for more effective implementation of practical work.

For the second area, developed countries could prioritize global educational needs, particularly in the stem fields, and provide more targeted economic support through international organizations like unesco. This support could help economically disadvantaged countries deliver highquality scientific education, contributing to their social and economic sustainable development.

Regarding the third area, science education spaces should be designed with collaboration in mind. This means creating flexible environments that allow for group work not only in laboratory settings but also in where students can be arranged in varied configurations, rather than the rigid, linear seating often found in traditional classrooms.

Finally, to address time constraints often associated with assessing practical work targeted assessment training for teachers and a more efficient design of science education curricula could help streamline the evaluation process.