Combining Hydroponics and Three-Dimensional Printing to Foster 21st Century Skills in Elementary Students

Abstract

This article reports on a mixed-methods evaluation of a hydroponics-based learning curriculum for fourth and fifth grade students that incorporated 3D design and 3D printing technologies. This study provides a better understanding of the extent to which experiential indoor gardening applications can be used in the formal curriculum as an effective teaching tool to sensitize participants to the prudent use of water, avoiding its wastage. The primary objective was to introduce students to the processes of 3D printing and hydroponics, while also assessing the enhancement of their 21st century skills. The participating students presented significant improvement in environmental knowledge scores about hydroponics, as well as high overall scores on collaboration, creativity, communication, and critical thinking (the 4Cs). The teachers noted the modern, innovative character of the program, as well as the ease of use of the included, offered, educational material.

1. Introduction

Clean and accessible water for all is a necessary part of the world we want to live in. There is enough fresh water on the planet to achieve this. But due to poor economic conditions and inadequate infrastructure, every year millions of people, especially children, die from diseases linked to inadequate water supply, sanitation, and hygiene. Water scarcity, poor water quality, and inadequate sanitation impact food security, household choices, and educational opportunities for the world’s poor families. Drought is affecting some of the world’s poorest countries, exacerbating hunger and malnutrition. By 2050, at least one in four people are likely to live in a country where they will experience chronic or recurring shortages of fresh water. Therefore, ensuring the availability and sustainable management of water constitutes an essential global goal, the foundation of which begins with the education of future citizens from their young age.

Water scarcity, the insufficiency of fresh drinking water to meet environmental or human needs, is inextricably linked to human rights. Access to potable water is considered a prerequisite, primarily for sustaining life, and secondarily for development, not only at the level of a given region, but also globally. This indisputable truth is proven by the fact that drinking water is the 6th of the 17 sustainable development goals of the 2023 agenda of the United Nations (UN) [1].

Therefore, the UN with the countries that constitute it, decided to undertake a wide, coordinated range of actions toward the realization of the 17 goals. This specific historical event is not perceived as negligible, since it determines policy-making decisions in all areas of human activity, including education. Consequently, education to secure water resources is a long-term goal and priority. Hydroponics is aligned with these scopes.

The term “hydroponics” or “soilless cultivation” describes the application of any method of growing plants, which is not carried out in the natural soil, but in a nutrient solution or in an inorganic inert substrate [2]. It is also found under the term “artificial cultivation”. Plant growth is based on the optimization of the environment of the plant crown through a greenhouse and the root with hydroponics, in which plenty of oxygen, and plenty of water, which have minerals, and nutrients in the right ratio, are ensured [3]. In natural soil, the more water there is the less oxygen, with the result that the two elements appear inversely proportional. In addition, the problem of the availability of inorganic nutrients for the plant root is found in the soil. Yes, nutrients are added to the soil, but these are not always available to the root because they are bound to the soil components or partially moved to the root.

It is an expanding method of agricultural production mainly in greenhouses thanks to its obvious advantages [2,3,4]. The most obvious advantage is considered the radical treatment of the problems caused to greenhouse crops by soil-borne diseases. Secondly, since in hydroponics, the soil does not come into contact with the plant, there is no need to disinfect the soil. In addition, watering and lubrication are automated, while, at the same time, reducing manual work. Finally and most importantly, water is saved because surface losses and deep penetration into the soil are limited. Weaknesses of hydroponic methods include slightly higher initial installation cost compared to conventional crops, greater care and attention in the operation of hydroponic systems because it does not provide high error tolerances, and although they have a relatively simple operating procedure, as a technologically advanced system, production requires the relevant knowledge [2]. Therefore, the familiarization with the concept and the procedures of hydroponics has been of critical importance since childhood. The aim of this paper is to take a step in the direction of education for the rational, prudent use of water, avoiding its waste during irrigation, by proposing a three-month project. The project, designed for familiarization with the principles of hydroponics, was implemented by 57 students of the fourth and fifth grade of a public elementary school in Greece.

2. Literature Review

Significant educational practices have been conducted around fostering positive attitudes toward hydroponics among younger ages. In a study that focused on cultivating positive attitudes toward science in underrepresented youth populations, 234 participated in an after-school hydroponics program [5]. Anxiety, desire, and self-concept were recorded before and during the program. The data showed that participants’ anxiety decreased and desire increased for both boys and girls during the program. Self-concept increased for female participants. Positive changes in attitudes suggested that the hydroponics program effectively fostered positive attitudes toward science among participants from populations typically underrepresented in science. The gender differences found on the self-concept scale indicate that the program may be particularly effective for girls and could contribute to increasing girls’ interest and participation in science. The primarily positive results indicated that hydroponics may be a useful educational platform to engage participants in year-round garden-based programming.

Student learning was assessed from crop production to recirculating cultivation for a 6-week module course at Kansas State University [6]. The unit design followed Kolb’s experiential learning model, where learners participate in a tangible experience, reflective observation, abstract reasoning, and hands-on experimentation, with groups of students responsible for producing lettuce or basil and chives using the nutrient film technique or recirculating pot culture system. The objectives were to discern whether this classroom experience would improve student confidence and understanding of not only recirculating solution culture systems, but also general crop nutrient management and improving higher-order learning skills of applying, analyzing, and evaluating information. Student learning was assessed by administering the same survey, which included questions to assess student perception at four separate times during the semester. A significant increase in low-order learning was noted after the material was presented during the course lectures, while an increase was also noted upon completion of the experiential module.

Aiming to describe planting environmental care through hydroponic programs, participating students carried out the hydroponic program with a floating raft system through the shaft technique [7]. Planting an environmental care stand was accomplished through various stages of the hydroponic program, namely, the seeding, planting, growing/growing, and harvesting stages. The results showed that the most dominant environmental care attitude of the students was to nurture plants, while the weakest environmental attitude of the students was to develop a comfortable environment.

University researchers worked with teachers and students attending a rural, southern high school to highlight obesity, cultivate an appreciation for gardens and vegetables, and align the project with curriculum standards [8]. By choosing strategies that engaged students in inquiry and rigorous academics, the project demonstrated that through collaboration, teachers could provide opportunities for students to learn methods of growing a wider variety of fruits and vegetables and to use the lesson standards and curriculum as a basis for promoting healthier eating habits.

Reporting on a mixed-methods evaluation of an indoor garden-based learning curriculum for fourth and fifth grade students that incorporated hydroponics and hydroponic technologies, a statistically significant improvement in environmental knowledge scores, as well as higher overall scores in environmental conservation, and in some cases, engagement in pro-environmental behaviors, were revealed [9]. Unexpected findings were found regarding the extent to which students with learning disabilities excelled. The study provided a better understanding of the extent to which indoor gardening technologies could be used in the formal curriculum as an effective teaching tool. Similarly, a teaching proposal based on learner-centered methodologies, with particular emphasis on project-based learning and collaborative learning was carried out through a hydroponics project in the fifth grade in a bilingual school in the province of Seville [10]. The main objective of this research was the design of an innovative teaching proposal that included collaborative work in the course of Natural Sciences by merging transversal contents from different fields using the aforementioned student-centered methodologies.

By gathering data on the feasibility and sustainability impact that hydroponics could have on the Skidmore campus, student surveys, existing literature, regional stakeholder interviews, Skidmore archives, and campus initiatives were organized and analyzed [11]. Data from Skidmore student surveys, existing literature, and consultation with relevant stakeholders strongly supported the economic, social, and sustainability benefits of hydroponic initiatives and that the Skidmore case was an ideal small-scale site for a successful hydroponics project. In summary, it was concluded that even with low economic, labor, and energy investments, hydroponics was the best commitment to support Skidmore’s sustainable and educational goals, and can easily be sustained and scaled for greater future efficiency and profit.

The crucial role of education in the adoption of novel practices and the need to broaden educational programs to reach a larger audience were proposed in a study that investigated the impact of education on hydroponic technology among modern farmers, contributing to a deeper understanding of the educational implications involved [12]. The study used a qualitative methodology, in-depth interviews, and observations as the data collection technique. The combined implementation of a complete hydroponic curriculum, with the use of a variety of training methodologies, has provided farmers with the necessary tools and knowledge to facilitate the transition from conventional farming practices to hydroponics. The training enhanced their understanding, building self-confidence and promoting sustainable, high-quality farming methodologies.

Exploring creative and critical thinking skills [13] at a STEAM project, which employed acid–base chemistry concepts as the principles through the hydroponics plants, it was deducted that important elements had been stimulated by active self-reflection and questioning followed by defining the problem, examining evidence, analyzing assumptions, and considering other interpretations. To optimize the plants’ growth, 76 students from two secondary schools in Indonesia were engaged in creating an aesthetic structure of hydroponics plants after designing the hydroponics pot structure.

The STEAM methodology was overviewed to determine the reasoning ability of 130 fifth grade students [14]. The outcomes, resulting from pre-test and post-test data collection, suggested the development of an attitude of thoroughness, self-reflection, and critical and creative thinking, which had an impact on their motivation to use mathematics in everyday life.

The co-existence of STEM methodology and 21st century skills is a factor in which research interest has increased in recent years. To explore the use of 3D printing machines in technology and engineering education, researchers developed a STEM-based vibration isolator activity using a 3D printer and repetitive modeling [15]. A quasi-experimental design was used, namely, a non-equivalent pretest–posttest control group design. The practical activity involved the design and making of earthquake-resistant structures. The experimental group used 3D printing technologies and repetitive modeling, whereas the control group did not. The conclusions were that repetitive modeling in the STEM-based design activity enhanced student imagination and that repetitive modeling, engineering design, and “conceiving imagination” were significant predictors of the students’ final products.

The background of STEM education in Hong Kong has been provided by [16], followed by identifying the problems of the current creative education such as the fact that the current STEM Maker education was not able to provide an effective learning experience for students. An education change was also proposed by integrating product design and computer-aided design (CAD) education into STEM Maker education by introducing new learning tools and an online learning system like Opro, a 3D-printed robot car design. It was established that the new learning tool Opro provided a significant learning experience. It enlarged the room of creation of the students, allowing students to consider the organization of the hardware and visual elements, and it made good use of 3D printing technology.

The results of a survey, that asked teachers from multiple grade levels and subject fields about the impact of 3D projects on student learning, reported parallels between teacher-identified skills and widely cited lists of 21st century skills [17]. Three-dimensional projects were admitted as a promising approach for preparing students for life and work in a digital age. The majority of 51 teachers from multiple grade levels and subject fields, who were using 3D printing in their classes, believed that these tools promote student learning of 21st century skills. Not only did using this technology introduce students to the procedures and practices of 3D modeling, but it also promoted creativity, technology literacy, problem solving, perseverance, and critical thinking. However, further in-depth research, on using 3D printing in engaging ways to motivate the learning of 21st century skills in school classrooms, was strongly suggested.

While overviewing the bibliography, numerous invitations for further exploration of the relationship among 3D printing and STEM were noted [13,15,17]. The flourishing of 21st century skills, among which are the four super skills, raises the need for research to ascertain their teaching methodologies through applications in real and modern educational environments. The need for 21st century skills is emerging as a response to rapid developments in technology, the labor market, and the globalized economy, which has a major impact on preparing children for the future. Critical thinking, innovation, and collaboration are key to successfully adapting to a rapidly changing world [17]. Adapting to a globalized society increases competition and requires the ability to work in a cross-cultural and multi-dimensional environment [17]. Consequently, the need for knowledge and skills that enable people to thrive in a complex and interconnected world is greater than ever. In this sense, education is no longer limited to traditional models or the transfer of knowledge, but to the development of skills to solve complex problems. The goals of 21st century education include preparing students to overcome challenges that require interdisciplinary and/or intercultural competencies [17]. These competencies include the ability to collaborate effectively with people from different backgrounds and to apply knowledge from various fields of knowledge to solve problems. At the same time, all of the existing studies suggest that to encourage responsible planetary citizenship, it is necessary to provide students with many opportunities to engage in nature-based learning and participate in food production [18,19,20]. Hydroponics may be an innovative learning tool to bring student-centered learning and STEM into the classroom [21,22,23,24]. Growing and harvesting food together offers many improvements to develop a sense of school community, bridging the gap between indoor and outdoor learning. Hydroponics also allows countries to teach children about healthy food choices and gives them constant access to a wide variety of fresh fruits and vegetables [25,26,27,28]. In general, existing studies highlight the importance of education in disseminating previous teaching practices, such as hydroponics and 3D printing, to develop 21st century skills in students. These practices not only promote the cultivation of positive attitudes toward science, but also enhance skills such as collaboration, communication, and creativity. However, these studies disperse globally at various age groups; therefore, any didactic application is important to demonstrate that this kind of work can be carried out even in a Primary Education context, in order to achieve results in the global educational process. The present project aims to evaluate the application of these methods in the context of teaching hydroponics and 3D printing to fourth and fifth grade students. Through this study, teachers are expected to acquire new tools and strategies for integrating and evaluating the teaching approach under consideration in their daily practice.

3. Purpose and Research Questions

The purpose of this study was to determine the contribution of a didactic intervention, a learning scenario about hydroponics and 3D printing, which was based on the didactic approach of “project-based learning”, on the 4Cs of the 57 students of the fourth and fifth grade of a public elementary school, and to evaluate the intervention.

In particular, the following research questions were raised:

• What is the effect of the teaching intervention about hydroponics and 3D printing on fostering the 4Cs (communication, collaboration, creativity, critical thinking) when students work in small groups?
• How do teachers and students evaluate the didactic intervention?
• Did the students respond to the activities of the teaching intervention, that is, did they participate by completing the required 3D design, printing and planting the hydroponic container?

4. Methodology

4.1. Research Process and Sample

For the implementation of the research, the case study was preferred, and qualitative and quantitative data were collected [29]. The research process was carried out in three phases.

During the first phase, the educational material for the scenario (consisting of students’ worksheets, presentation files, and teacher reflection sheets), as well as the rubric (which tested the students’ 4Cs), were compiled. The abovementioned materials were initially presented to the teachers who were eager to participate in order to express their judgments and to proceed with modifications. The phases of the learning scenario were presented, discussed, explained, and made available in printed and digital form so that there is flexibility in access and use. The teachers’ perspective was essential prior to the implementation. Since they were going to apply the educational scenario in their classrooms, their insights were crucial for ensuring that the materials were suitable. To clarify, the teachers involved in this process were all qualified educators with significant expertise in their respective fields. Two of them held Master’s degrees in Pedagogy and the third one had a 400 h specialized training certificate in STEAM education. Their experience in integrating technology and hands-on learning into the curriculum allowed them to provide valuable insights into the appropriateness and effectiveness of the instruments used, such as worksheets, presentation files, teacher reflection sheets, and the rubric. Based on their observations, the necessary changes were made and prepared in their final form. To ensure consistency in scoring across different observers, two training sessions were provided to teachers regarding the use of the rubric. The first session included an overview of the rubric’s structure, a detailed description of each performance level, and discussions on how to observe and evaluate students according to specified criteria. During the second session, calibration exercises took place, where teachers practiced scoring student performances using rubric together.

In the second phase of the implementation, the three teachers followed the phases of the scenario while the students participated in the educational activities and interacted with the educational material. During the first hour of the teaching intervention, the students’ ideas about hydroponics were discussed to record any previous ideas. The discussions involved interactions primarily with the research team and the teachers who were providing the instruction, ensuring that the insights gathered were accurately captured during the implementation of the educational scenario.

In the last phase, the students completed a self-evaluation form regarding the learning goals and self-improvement criteria, while the teachers completed an evaluation form regarding the relevance of the scenarios’ topic, the learning material, the pedagogical approach, and a self-reflection form.

Informed consent was obtained from all parents or guardians of the participating students, through a formal consent form that detailed the objectives, content, procedures of the teaching, and duration of the research. This consent form was sent home with the students and was required to be signed and returned prior to their participation in the study. The research was kept completely anonymous to ensure the protection of personal data. No sensitive information was collected about the participants, but only relevant information about their learning outcomes was collected in order to evaluate the educational process. Eighteen students of the fourth grade and 39 of the fifth, 57 students in total of the primary school participated in the research. The students attended three classes at the same elementary school.

4.2. Pedagogical Background and Learning Scenario

The educational material was based on the didactic approach of the team-collaborative method and was organized around the communicative form of student involvement and participation [30]. In its context, the element of cooperation between students in groups under a common goal was emphasized, while the spontaneous expression of opinions, a sense of “belonging”, taking on roles, and cultivation of individual responsibility toward the group were expected.

Due to the diversity of the students’ ideas and their previous knowledge, the teacher’s role was transformed to support the cohesion and synergies of each group and to function with guidance and support as criteria [31]. The scenario prompted students to apply design and engineering principles after familiarizing themselves with hydroponics. It is related to the fifth grade physics syllabus “Molecules-cells-life-biological systems”. It is based on the theory of knowledge construction and the epistemology of STEAM while following the model of project-based learning. The application of design principles and 3D design can promote creativity [32]. By designing and printing 3D objects, using CAD software, one gains an understanding of how 3D shapes best fit together and create 3D models. Being able to understand how 3D shapes work and fit can also lead to improvements in students’ spatial intelligence. Spatial intelligence, also known as visual–spatial intelligence or spatial reasoning, is one’s ability to imagine or visualize in the mind, the positions of objects, their shapes, and the movements they make to form new spatial relationships [32]. It is the ability to perform spatial imaging and spatial reasoning in the head. Although considered vital in many academic and professional fields, it is rarely included in the primary school curriculum. It is an educational scenario that starts from hydroponics and moves to the 3D design of a hydroponic pot.

Learning principles of social and constructive constructivism were adopted. It is considered indisputable that students have formed their own perceptions as derivatives of daily experience in the school or wider social context, which differ from scientific ones, that is, they have alternative ideas. School learning is perceived as a process of constructing knowledge through interaction with peers during the construction of an object, which has meaning for them, in the context of an authentic activity [30]. The scenario emphasized exploratory inquiry, in line with the principles of inquiry learning and teaching, believing that scientific methods can be taught to children. Learning was implemented through questions, without an exclusive focus on the correctness of the answers, but on the exploratory search for solutions or answers to a problem. Students were enabled to learn through their involvement in defining the problem, exploring the use of information to solve the problem, developing ideas, using research methods, proposing generalizations of ideas to new processes, and reflecting on the learning process [30]. The solution to the realistic, problematic situations that students were asked to face, depended on internal and external representations as much as on direct interaction with the real world and the real environment.

The activities of each phase engaged the students with specific practices. The activities from the second phase are presented as follows.

Step 1-Empathy (20 min): The teacher describes what a hydroponic pot is through the presentation posted on an educational blog so that students develop knowledge about the users of this product (how they might use it, what they might say, think, or even feel). The characteristics of the pot were as follows:

• The inner container (pot) goes inside the outer container (water container).
• At the bottom of the inner pot, there are a series of holes that absorb the water.
• Water is filled in the outer container so that the suction holes are covered.
• There are four more holes in the inner container in the cone part. These are holes that allow the soil to breathe. When filling the outer container with water, these holes must not be covered.
• The soil and seeds will be placed in the inner container. Do not worry if a little soil gets into the outer container.
• There is no need to water the self-watering pot as often as a standard pot. Simply check that the suction holes are covered with water. After some experimentation, you will know how often watering is required.

Step 2-Problem definition (20 min): The students were divided into groups of three, depending on the availability of computers in the ICT laboratory. By focusing on user needs, opportunities for innovation began to emerge. Was there a problematic feature that may be bothering many users? What user needs might not be met? were questions that troubled the participants.

Step 3-Generate ideas (20 min): Brainstorming triads jot down crazy, creative ideas that address unmet user needs identified in the definition phase. Trios had absolute freedom. No idea was too much and quantity replaced quality. In this phase, team members came together and many different ideas were sketched out. They shared ideas, mixed and mingled, and built on others’ ideas, as well.

Step 4-Designing the prototype (45 min + 45 min): For this step, students went to the ICT laboratory and practiced in pairs using the Tinkercad digital environment, in an effort to design their idea. Upon completion of the designs, checking by the class teacher, and saving them, the designs were printed on the 3D printer. Safety rules were followed to eliminate the possibility of physical harm to children. The students were the ones who gave the print commands, but the adults were the ones who detached the printed originals from the printer base. Additionally, a safe distance was maintained from the moving parts of the 3D printer.

Step 5-Presentation of the upcoming product test (45 min): The groups planted seeds of aromatic plants and afterward presented their product to their classroom.

Step 6-Extension (Educational visit): The 57 students visited the “Polymers Lab” Chemistry department of Democritus University of Thrace, where they monitored the step-by-step 3D printing process, the specialized equipment, the improvement of their designs, and received their refined pots and a 3D printed souvenir gift for everyone.

Step 7-Presentation: The students presented the concept of hydroponics and their 3D printed pots with the developed plants at the “2nd Students Conference”.

4.3. Data Collection Process

4.3.1. Rubric Description

A rubric is considered a graded criteria scale that belongs to the category of qualitative evaluation methods [33]. The 4Cs rubric was constructed to determine the level of the students’ observed skills (Appendix A). The construction was based on the Herro, Quigley, Andrews STEAM rubric because it provided a systematically organized model for K-12 researchers and teachers to assess students when engaged in STEAM activities [34].

Dimensions of the Rubric

To validate the rubric, the examination of its technical quality was necessary. The process was conducted in two strands. The first strand included seven expert reviews of the rubric and an assessment of the importance of the characteristics. At the experts’ team, highly qualified teachers, who possessed advanced degrees and substantial experience at pedagogical practices relevant to K-12 education, were included to ensure that the rubric appropriately measures the targeted construct. To confirm whether the experts believed that each characteristic was a strong indicator, they were given a second question asking them to indicate the extent to which they agreed that each characteristic captured what they would expect them to provide on each dimension. They were asked to rate their agreement using a 5-point Likert scale.

The building blocks of a rubric were [35] as follows:

The criteria of dimensions refer to the specifications that a behavior should meet to be considered suitable and complete. In fact, the evaluation criteria described all the characteristics that the behavior displayed should have. At each of the four skills, five dimensions were rendered (Appendix A).

Specifically, five dimensions of communication criteria were posed: To respect the ideas of the rest, to display socially acceptable language and behavior, to listen and respect the order, to state personal point-of-view, and to consider the opinions of others.

Five dimensions of collaboration were determined: To check assignments/projects with peers, to negotiate roles in the team, to share and work toward task/project completion, to check the understanding of process and/or content, and to offer feedback, assistance and/or redirection of the work/project.

Five dimensions of creativity were also set: To present fluency in expression and flexibility in thought, to modify/edit an existing design, to create something new, like a design/composition, to propose/generate ideas or elaborate an existing idea and defend it, and to reflect on the produced result.

Finally, five dimensions of critical thinking were raised: To formulate appropriate probing questions, to summarize a topic or argument, to analyze data, to provide research/evidential information, and to explain the impact of new information.

Rating Categories

The standards were as follows: Graded levels constituted the descriptive assessment of a rubric, reflecting the degree of achievement of the evaluation criteria. The quality fluctuated from minimum, assigned the numerical value (1), more effort is required (2), to maximum, excellent effort (3).

The description of the criteria were as follows: At each level, there was a precise, detailed description of the criteria that the students’ behavior should manifest, so that one can be classified at each level. In short, it was defined as what may be considered excellent or poor (Appendix A).

For example, respecting the ideas of others is crucial in a collaborative environment. When more effort is required, the student dismisses others’ ideas without apparent reason, indicating a closed attitude toward new suggestions or viewpoints. In cases of satisfactory effort, the student occasionally allows others to share their ideas, and may only diplomatically disagree in certain instances, suggesting a lack of consistent politeness or understanding toward others’ perspectives. On the other hand, an excellent effort is characterized by the student that consistently allows others to contribute their ideas and disagrees diplomatically, demonstrating both respect and acceptance of different opinions.

Similarly, the use of socially acceptable language and behaviors also plays a significant role in interactions. When more effort is required, the student employs socially inappropriate language and behaviors when engaging with peers, which may include rudeness or insults. With satisfactory effort, the student sporadically uses socially acceptable language and behavior, showing respect on occasion but not consistently. In contrast, an excellent effort is reflected in the students’ unyielding use of socially acceptable language and behaviors when communicating with peers, showcasing ongoing politeness and respect.

The numeric scale was as follows: Each performance level corresponded to a rating. The higher score corresponded to the better performance, while the lower score was attributed to the lowest performance, respectively. Each skill was assessed on a scale from 5 to 15. This utters that the lowest score a student can achieve is 5, while the highest is 15. Subsequently, the total score ranges from 20 to 60, that is calculated by adding the lowest possible scores (5 for each skill, totaling 20) to the highest possible scores (15 for each skill, totaling 60).

4.3.2. Data Collection Through the Teachers’ Evaluation and Self-Reflection Form

The educational scenario was considered a pedagogical tool. It was recommended to be evaluated by its creator, as well as by other educators. The evaluation modules of the scenario were completed after its implementation with the aim of controlling the act of teaching and the relevance of the scenarios’ components (Appendix B).

The evaluation form consisted of three axes:

• Evaluation in terms of the theme of the scenario.
• Evaluation in terms of the pedagogical approach.
• Evaluation of the educational material.

Each of the three axes was rated using a three-point scale. Poor (1) indicated that the aspect does not meet expectations, satisfactory (2) suggested that the aspect meets some expectations but could be improved, and very good (3) signified that the aspect meets or exceeds expectations.

Four criteria evaluated the theme. The evaluation criteria included compatibility with the curriculum, which checked whether the scenario aligns with the educational program, ensuring its integration into the timetable; relevance to the cognitive level of the students, assessing whether the scenario was suitable for the developmental stage and understanding of the students; feasibility within the proposed timeframe, which evaluated whether the time allocated for teaching the scenario was adequate; and the currency and modernity of the scenarios’ content, checking whether it reflects contemporary practices or knowledge. Additionally, a section for comments allowed teachers to provide qualitative feedback or explanatory notes regarding each of these criteria.

The second axe focused specifically on the educational approach of the scenario, emphasizing its effectiveness in applying STEM principles and collaborative teaching. It aligns with the syllabus, corresponds to the cognitive level of the students, meets the proposed implementation time, and is current and modern. Additionally, a section for comments was included for any further insights or observations.

This last axe assessed the educational materials utilized in the scenario, including the presentations and worksheets provided to students. The criteria for evaluation encompassed whether the materials were aligned with the syllabus, corresponded to the cognitive level of the students, aligned with the proposed implementation time, and were user-friendly and accessible for students. This last criterion specifically evaluated the usability and accessibility of the educational materials. Similar to the other sections, there was also a field for comments that provided an opportunity for specific feedback regarding the materials.

The self-reflection consisted of three questions which were formulated as “I have followed the steps as suggested in the “Educational Activities” field”, “I asked for and had support in obstacles that I encountered that made my work difficult”, and “Note down observations, suggestions for improvement, difficulties, thoughts that you think can contribute to improving the scenario”. There was also a provision of free space for the brief formulation of the methods in the first two cases, and a three-point scale was applied to determine the degree of the manifesting behavior (poor, satisfactory, and very good).

4.3.3. The Students’ Self-Evaluation Form

The students’ self-evaluation form was a scale of graded criteria designed to evaluate a specific activity according to the self-improvement and learning goals criteria of the learning scenario. For the completion of this evaluation, students were given clear instructions. They were asked to indicate their level of agreement with each statement using a four-point scale, descriptive (poor, average, much, very much) (Appendix B).

The self-improvement criteria were designed to assess students’ perceptions regarding their performance and involvement in class activities, offering a rating scale ranging from “Poor” to “Very much”. These criteria included statements such as believing they need to improve their performance, feeling adequate in responding to tasks, and recognizing their contribution to group work, as well as their desire for increased collaboration and involvement. Similarly, the learning goals criteria evaluated students’ abilities to utilize information and data, apply learned concepts in daily life, design hydroponic pots, and effectively use Tinkercad with guidance. Students also reflected on the utility of information gained during educational visits and expressed their interest in hydroponics, indicating a comprehensive approach to evaluating self-assessment in both their personal growth and educational goals.

4.3.4. Photographic Material of Key Moments

The photographic material consisted of qualitative data. Several steps aimed at capturing key moments throughout the educational intervention focused on hydroponics and 3D printing.

Initially, during the 3D design process, photographs were taken to document the students’ engagement with the digital environment. Students worked in pairs, experimenting with design ideas and utilizing various tools within the software. The teachers carefully photographed students (avoiding their faces) as they manipulated digital elements on their screens.

Following the design phase, the focus shifted to the 3D printing process. As the students’ designs were transferred to the 3D printer, cameras captured moments from the setup to the actual printing. Teachers documented the students’ anticipation and excitement as they observed their digital models transforming into tangible objects.

Finally, the last set of photographs recorded the planting process. After the 3D printed hydroponic pots were completed, students planted aromatic seeds within them. The documentation included various stages of this activity, from preparing the pots with soil and seeds to watering them and observing their placement in an appropriate location for growth.

The thematic analysis process, which is based on qualitative data such as photographic material, involves several stages to ensure the accurate and systematic evaluation of the material. The first step was data collection, where the selection of photographic materials related to the research purpose and research questions was crucial. The photographs were carefully collected to reflect the core themes and objectives of the research. Following data collection, researchers needed to familiarize themselves with the photographs. This means meticulously observing them and noting observations and thoughts about what they might represent [36].

In the next stage, researchers developed codes for the images, marking specific characteristics observed in the photographs. After the codes were developed, researchers sought common elements among them and developed broader thematic categories. These themes had to be identified in relation to the research objectives and supported by the photographic material [36].

At this point, a review of the themes was conducted to ensure they were sufficient and analytical. It was crucial that the themes reflected the data and were capable of complementing the research questions [36]. Finally, the themes were revised and finalized.

5. Results

For the analysis of the research data, the convergent parallel design method was used, where qualitative and quantitative data were analyzed in parallel. The sets of results were then merged [29]. IBM SPSS Statistics 29.0.2.0 was considered suitable for the quantitative analysis, whereas qualitative data, such as the photographic material of the 3D design, printing, and planting processes, functioned as complementary.

Each process supported and enhanced the effectiveness of the hydroponic system while facilitating the integration of learning through 3D design and printing technologies. The qualitative data revealed themes such as engagement, satisfaction, and the applicability of the hydroponics and 3D printing activities in real-world contexts. The photographic material of the 3D design, printing, and planting processes contributed to documenting participation and the process, confirming engagement and the production of final products.

The following section presents the results of the research as they emerged from the statistical processing of the quantitative data and the thematic analysis of the qualitative data. The information obtained from the qualitative analysis complements the quantitative findings, providing a richer understanding of the impact of the teaching scenario.

5.1. Collaboration, Creativity, Communication, and Critical Thinking (4Cs) Rubric Results

No missing values were observed. For all 57 students, the 4Cs skills were determined based on the rubric behavior that each teacher completed. Collaboration was found to be the most developed skill followed by communication, in contrast to creativity (Figure 1). The effort put in, by the participating students, was highly rated as excellent across the skill set. This fact was confirmed by the prices that the mode and median received (

Table 1. Statistical values of the 4Cs rubric.

Statistics
		Class	Collaboration Total	Creativity Total	Communication Total	Critical Thinking Total	4Cs Total
N	Valid	57	57	57	57	57	57
	Missing	0	0	0	0	0	0
Mean		1.68	2.82	2.57	2.73	2.61	2.77
Median		2.00	3.00	3.00	3.00	3.00	3.00
Mode		2.00	3.00	3.00	3.00	3.00	3.00
Sum		96.00	96.00	147.00	156.00	149.00	158.00

).

5.2. Teachers’ Evaluation Results

No missing values were observed. The values of the first axis revealed that the scenarios’ theme was very current and modern, highly corresponded to the proposed implementation time, and revealed average correspondence to the cognitive level of the students (

Table 2. Statistical values of teachers’ evaluation form.

			Theme				Pedagogical Approach				Educational Material
		AA	Is Aligned with the Syllabus	It Corresponds to the Cognitive Level of the Students	It Corresponds to the Proposed Implementation Time	It Is a Current, Modern	Is Aligned with the Syllabus	It Corresponds to the Cognitive Level of the Students	It Corresponds to the Proposed Implementation Time	It Is a Current, Modern	Is Aligned with the Syllabus	It Corresponds to the Cognitive Level	It Corresponds to the Implementation Time	It Can Be Used by (or for) Students, and It Is Easy to Use
N	Valid	3	3	3	3	3	3	3	3	3	3	3	3	3
	Missing	0	0	0	0	0	0	0	0	0	0	0	0	0
Mean		2.00	2.33	2.33	2.66	2.33	2.33	2.33	2.33	2.33	2.66	2.66	2.66	2.66
Std. Error of Mean		0.57	0.33	0.33	0.33	0.66	0.33	0.33	0.33	0.33	0.33	0.33	0.33	0.33
Median		2.00	2.00	2.00	3.00	3.00	2.00	2.00	2.00	2.00	3.00	3.00	3.00	3.00
Std. Deviation		1.00	0.57	0.57	0.57	1.15	0.57	0.57	0.57	0.57	0.57	0.57	0.57	0.57
Variance		1.00	0.33	0.33	0.33	0.33	0.33	0.33	0.33	0.33	0.33	0.33	0.33	0.33
Range		2.00	1.00	1.00	1.00	2.00	2.00	2.00	2.00	2.00	2.00	2.00	2.00	1.00
Sum		6.00	7.00	7.00	8.00	7.00	7.00	7.00	7.00	7.00	8.00	8.00	8.00	8.00

). Regarding its pedagogical approach, the high correspondence to the time and the possibility of in-class implementation were disclosed. However, the approach revealed average correspondence to the syllabus. This is attributed to the fact that the scenario was based on the new curricula which are being implemented on a pilot basis in selected schools and not universally throughout the country. Finally, the results of the third axis unveiled not only that the educational material highly corresponded to the time and to the cognitive level, but it was also very easy to use.

Through the self-reflection form, the participating teachers uncovered that they followed the didactic planning sufficiently and that they were highly supported to overcome any obstacles (

Table 3. Statistical values of teachers’ self-reflection form.

Statistics
	AA	Followed the Steps as Suggested in the “Educational Activities” Field	I Asked for and Had Support in Obstacles That I Encountered That Made My Work Difficult
N	3	3	3
	0	0	0
Mean	2.00	2.00	3.00
Std. Error of Mean	0.57	0	0
Median	2.00	2.00	3.00
Std. Deviation	1.00	0	0
Variance	1.00	0	0
Range	2.00	0	0
Sum	6.00	6.00	9.00

).

5.3. Students’ Self-Evaluation Results

The students’ self-evaluation results could be characterized as encouraging. Regarding their performance, the students did not notice any need for more improvement, more collaboration, or more involvement in the group tasks (

Table 4. Statistical values of students’ self-evaluation form.

Statistics
		I Believe I Need to Improve My Performance	I Believe That I Need Help to Respond to Tasks	I Feel Satisfied with my Contribution to the Group	I Think I Should Be More Involved	I Believe I Should Collaborate More	I Am Able to Utilize Information and Data	I Can Use What I Learned in My Daily Life	I Understood What Is a Hydroponic Pot	I Was Able to Design My Own Hydroponic Pot on Paper	I Was Able to Use Tinkercad with the Help of the IT Teacher	I Tried to Use Tinkercad in the Classroom from Tablets or Laptops	I Believe That I Obtained Useful Information from the Educational Visit	I Found the Planting of Plants in the Hydroponic Pots Interesting	I Was Interested in Learning More About Hydroponics
N	Valid	49	49	49	49	49	49	49	49	49	49	49	49	49	49
	Missing	0	0	0	0	0	0	0	0	0	0	0	1	0	0
Mean		0.83	0.55	2.00	0.75	0.51	1.73	1.89	2.30	2.37	1.95	2.02	1.81	1.83	1.75
Median		1.00	0	2.00	0	0	2.00	2.00	3.00	3.00	2.00	2.00	2.00	2.00	2.00
Mode		0	0	3.00	0	0	2.00	3.00	3.00	3.00	3.00	3.00	1.00	3.00	2.00
Std. Deviation		0.85	0.73	1.09	1.01	0.71	1.09	1.14	1.00	0.84	1.05	1.07	0.95	1.17	0.94
Variance		0.72	0.54	1.20	1.02	0.5	1.19	1.30	1.00	0.7	1.12	1.14	0.92	1.38	0.89
Sum		41	27	98	37	25	85	93	113	114	96.00	99	87	90	86

). On the contrary, they shared confidence about understanding, utilization, and even designing of a hydroponic pot.

5.4. Core Themes and Categories

The analysis of the research data revealed several core themes and categories that emerged from the students’ experiences during the project (Figure 2A–E).

• Core Theme 1: Engagement in digital design

Category 1.1: Collaborative learning: Illustrations captured students working in pairs on the 3D design project, showcasing their teamwork and shared problem-solving skills. The interactions among students were characterized by discussions and exchanging of ideas as they navigated through the design challenges (A).

Category 1.2: Interaction with technology: Photos documented students exploring 3D modeling software, exemplifying their growing familiarity and adaptability with digital tools (B).

• Core Theme 2: Transformation from digital to physical

Category 2.1: Accomplishing technical tasks: Visual documentation of the 3D printer showcased various technical aspects and the learning outcomes associated with operating such machinery (C).

• Core Theme 3: Hands-on learning experience

Category 3.1: Practical application of knowledge: Photographs depicted students actively participating in the planting process, cementing the cycle from design to real-world application. This hands-on engagement allowed students to apply their theoretical knowledge about hydroponics and environmental science in a practical setting, thereby deepening their understanding of sustainable practices (D).

Category 3.2: Connecting science and nature: Documentary evidence of the planting activity illustrated the students’ active engagement with nature through hydroponics. This component of the project fostered an understanding of ecological principles and sustainable practices, creating a meaningful connection between scientific concepts and the natural world (E).

Overall, the results demonstrated a rich, interactive learning environment where students thrived in collaborative and hands-on educational experiences, integrating technology with practical applications in nature. The evidence collected underscored the project’s success in promoting critical skills among elementary school students.

6. Discussion

This noteworthy project was an important initiative to raise awareness about the conscious use of water through the introduction to the concept and basic principles of hydroponics. It was also a STEAM intervention that permitted the monitoring of 4Cs. Its contribution was multifaceted.

To begin with, students were allowed to participate in a STEAM program with an emphasis on student-centered learning, which incorporated, apart from elements of sustainability and environmental education, particularly elements of technology, such as 3D design and 3D printing. This feature enhanced students’ abilities to draw on paper and use the Tinkercad educational environment [30]. The majority declared “I was able to design my own hydroponic pot on paper” and “I was able to use Tinkercad with the help of the IT teacher”.

In addition, on a cognitive level, the participants were familiarized with hydroponics, which is a concept that is not very widespread, at least in the city environment where they live, in agreement with previous research [6,8,9]. They were provided with the opportunity to increase knowledge, physical activity, work together with others, and observe experientially the plants’ development. They stated “I understood what is a hydroponic pot”, adding “I was interested in learning more about hydroponics”. Not only the importance of agriculture but basic skills, such as caring for, planting, and watering were exercised [26], as well as connecting or reconnecting with nature, such as outdoor-based learning [20]. As the majority of the participating students admitted “I can use what I learned in my daily life”, the authentic context performed the basis for understanding plant basics, how to grow food, and collective learning.

Hydroponics was a valuable way to incorporate the 4Cs into a STEAM project [20]. Competencies such as collaboration for achieving mutual goals, creativity while designing on paper and on a PC, critical thinking to overcome obstacles and solve problems, as well as communication and dialectical processes during the whole project were authentically fostered. Specifically, the statistical analysis revealed that students in this innovative framework exhibited a mean score of 2.77 in the 4Cs total. As one student said, “Participating in the project for producing hydroponic pots made me feel like I can design more objects”. Hydroponics may support learning by scaffolding learning through and rebounding from challenges, learning resourcefulness in addressing these challenges, while supporting well-being through exposure to plants [22].

Regarding the content of the teaching scenario, not only its modern character, its completeness, but also its ease of use, as underlined by the participating teachers who willingly and accurately implemented it, were evident. The evaluation results were consistent with the active participation, team-centered learning, pleasant mood of the participants, and lively interest in the scenario. All the teachers stated that they wish to participate in environmental projects by leading a group of students. When asked about the overall offering of this educational experience, the results were impressive. Students broadened their knowledge based on STEAM, became more familiar with new technologies and learned cooperation and teamwork, and teachers understood the need to integrate technology into education. A participant’s statement was characteristic: “Kids in other schools would love it”.

The significance of the presented activity lies in the fact that it combined modern technological applications, such as hydroponics and 3D printing, with education, providing students with the opportunity to practically understand sustainability and responsible resource management, such as water. This approach enhanced student engagement and the development of important 21st century skills, such as collaboration, communication, critical thinking, and creativity. In relation to previous curricula, which were often focused on theoretical models and less on experiential learning, this may have resulted in a disconnection for students from the real application of their knowledge. Conversely, the activity being examined offers an interactive experience that encouraged students to actively participate in exploring concepts related to sustainability, which is essentially more useful and relevant to the challenges of the modern world. In summary, this intervention was not merely an innovation, but represented a necessary shift toward a more experiential and sustainability-oriented teaching method that has proven to be more effective and appropriate for educating today’s students. The project was easy to implement and had positive results, with students reporting interest in future environmental projects.

7. Conclusions

Taking into account the research purpose, the research questions, and the multitude of collected data, the allocation of deductions is substantial. To begin with, targeted 4Cs were determined when students collaborated in small groups. High levels of collaboration, while working in shared activities were demonstrated. Students formed collaborative bonds in groups and experienced the sharing of tasks, molding productive shared products.

Students’ participation in discussions, as well as the communication of ideas and suggestions enhanced the collaborative learning experience among them. In a learning context, they expressed their opinions and respected the opinions of others, thus promoting their interaction and social behavior. The 3D design and printing processes boosted creativity. The projects’ contributions required reflection and innovation, as they were asked to design a hydroponic pot by combining different ideas.

Through problem-solving procedures, the difficulties that arose regarding the production of hydroponic pots, were addressed as students were forced to think critically about user needs and the possibilities for improving their design. These procedures included analyzing and evaluating their proposals, which was seen as strengthening critical thinking.

Despite the fact that participating students came from the most populous school in town, the selection of a relatively small sample of 57 students may influence the generalization of the results. This sample group might also impact the possibility to generalize the findings to different population characteristics such as age groups, region of residence (town-village), and students’ differentiating learning characteristics (learning difficulties, minorities). As a result, the need to apply to wider and more diverse populations is highlighted.

Teachers expressed high levels of satisfaction about the interventions’ topic, which was considered contemporary and relevant to the proposed implementation time. They also spontaneously manifested a desire to participate in similar projects in the future, which suggests that the experience was quite encouraging and educational. Furthermore, the teaching material was assessed as very user friendly and, at the same time, responsive to the students’ cognitive level. Students also reported their experiences, expressing satisfaction and confidence at the understanding and application of acquired knowledge. In general, the teaching intervention revealed a positive impact both for teachers and students, reinforcing the belief that such approaches may improve the learning process.

However, inadequate teacher training was recorded as the most important barrier to teaching within the existing curriculum. Technological infrastructures in schools that do not meet the needs of a 3D design and 3D printing course and the reduced time available for teachers for activities beyond the curriculum troubled the evaluators. They initially also shared the opinion that 3D design and 3D printing had more relevance to IT and not to other educational subjects. Therefore, the need for training of teachers was demonstrated, who, as the paper recorded, wished to be involved with robotics and have shown a warm interest in hydroponics, on the one hand, and 3D design and 3D printing, on the other hand.

It would be safe to admit that the students responded to the activities of the teaching intervention by completing the required 3D design, printing and planting of the hydroponic container. Evidence that support the statement are students’ digital collaborative class photos from the Tinkercad website, snapshots of hydroponic pots printing process, and finalized planted prototypes.

Several possible implications can be derived from the implementation of the educational scenario. The positive outcomes of the study can inform curriculum developers about the benefits of including hands-on, experiential learning modules in existing curricula. This could lead to a broader incorporation of technology and sustainability topics in primary education.

The research advocates for contextual and nature-based learning experiences that bridge indoor and outdoor environments. This could inspire educational institutions to create more integrated learning environments that relate classroom activities to real-world applications.

Finally, the positive results demonstrated in a small-scale setting indicate that similar models could be implemented in other schools or regions. This has implications for educational policies aimed at funding and supporting innovative educational programs, especially in underserved areas.

In summary, the study implies a shift toward more innovative, engaging, and sustainable educational practices that prepare students for the complexities of the modern world while fostering important skill sets.

8. Limitations

To complete the project, meaningful factors that impeded the process should be pinpointed. The selection of fourth and fifth grade students was deliberate in consideration of the alignment between the curriculum and the students’ readiness to fully engage with the materials and activities. Younger students may not possess the cognitive readiness, while older students might present different educational needs and expectations, which could lead to variations in outcomes.

The study focused mainly on the short-term effects of the teaching intervention on students’ 4Cs and their familiarity with the principles of hydroponics. It did not explore whether students retained or further developed these skills in their later education or daily lives through a longitudinal approach. Furthermore, the potential long-term impact of the skills gained during the intervention on students’ behavior and their approaches to future learning opportunities, as well as their abilities to collaborate, communicate, think critically, and practice responsible water usage, remains unexamined.