Active learning in STEM education

Although inquiry-based learning originated in physics and science education, where students are involved in authentic scientific practices, it also occurs in mathematical or technological contexts. This approach to learning mirrors the procedure and thinking that scientists, engineers, and innovators use in the real world. As a result, inquiry-based learning naturally suits to related disciplines such as science, technology, engineering and mathematics or STEM disciplines. In this paper we present examples of STEM related projects designed for students in order to solve real-life problems using digital technologies to support inquiry represented by modelling or experimental approach. Examples of interdisciplinary projects involve motion of sportsmen, sky or scuba divers, or solving other problems using various programming platforms. Students working on interdisciplinary projects effectively use and deepen their knowledge from different subjects and develop skills to use smart technologies and coding. As a result, they move from the role of passive users to active learners and designers.


Introduction
It is well-known for a long time that active learning can bring positive effect on students´ learning outcomes.Active learning can be represented by various strategies such as problem-based learning, cooperative/collaborative learning/group work, think-pair share or peer instruction, inquiry-based science education strategies and many others.Although inquiry-based learning originated in physics and science education, where students are involved in authentic scientific practices (e.g.planning and designing experiments and collecting data), it also occurs in mathematical or technological contexts.This approach to learning mirrors the procedure and thinking that scientists, engineers, and innovators use in the real world.As a result, inquiry-based learning naturally suits to related disciplines such as science, technology, engineering and mathematics or STEM disciplines [1].High quality education in STEM disciplines has been in the focus of many education systems worldwide over the last two decades.One of the reasons is a rapidly changing world with radical technological changes that needs well-educated people equipped with knowledge and skills to be successful in workplace where science and technology is prevalent.In addition, it is also a response to low level of students´ interest and engagement in STEM disciplines and concerns about shortages in qualified graduates in STEM field needed for STEM skilled labour [2] [3] [4].Current upper secondary schools´ curriculum in Slovakia is based mainly on isolated approach to teaching and learning within separate STEM related teaching subjects.Even though the current STEM subjects´ curricula emphasize not only the development of knowledge but it strongly emphasizes development of skills and competencies related to inquiry, the educational standards of science, mathematics and informatics are more or less independent [5].However, real-life problems are usually complex and require to use knowledge from different areas as well as various competencies and skills.Students during their study should be exposed to solving such problems.We have developed a series of examples of problems designed for students in the form of STEM related projects that can complement and enhance teaching and learning STEM subjects.The designed STEM projects examples utilize digital technologies to support inquiry represented by modelling or experimental approach.

Inquiry-based and project-based learning in STEM education
Inquiry-based learning (IBL) in STEM is closely related to project-based learning (PBL).They both represent active learning student-centred strategies.Inquiry-based learning is centred around a research question that students answer through research.In STEM subjects students conduct investigation that involves mainly experimentation or modelling, in particular, when students follow the steps of inquiry cycle from conception, planning and design of experimental or modelling procedure, through implementation of the designed plan, analysis and interpretation of gained results to their communication and application and follow-up [6].There are many definitions of project-based learning (PBL).Holbrook, as presented in [7], defines project-based learning as a "model for classroom activity that shifts away from the classroom practices of short, isolated teacher-centred lessons and instead emphasizes learning activities that are long-term, interdisciplinary, student-centred and integrated with real-world issues and practices".Goodman and Stivers [8] characterize PBL as a dynamic approach to teaching in which students explore real-world problems and challenges, simultaneously developing 21 st century skills while working in small collaborative groups.Krajcik and Shin [9] propose six key characteristics of PBL that teachers should be aware of when implementing PBL: 1) driving question that has an authentic link to real world, is open-ended and needs to understand scientific concepts related to STEM subjects, 2) learning goals: students gain a deeper understanding of the topic, ask questions and collaborate, the PBL unit should last for longer than one lesson 3) scientific practices: students should actively use scientific methods in order to solve and study the driving question 4) collaboration: students carry out research in collaboration with each other, 5) using technological tools, 6) creating an artefact or an end product that answers the driving question.Project-based learning has also been defined as a "special case of inquiry" [10].STEM project-based learning and inquiry-based learning go hand-in-hand in terms of student-centred instruction.In both cases students work on a problem and seek an answer to a research question while applying scientific methods that require specific skills usually known as inquiry skills [6].However, Safin [11] points to differences between IBL and PBL that involve the following aspects.In IBL students conduct investigations and make their own discoveries as opposed to producing a product or artefact that represents what they have learned.STEM project-based learning is less structured than IBL since groups of students has to organize their own work, and manage their own time.PBL is typically more interdisciplinary, i.e. students study one problem from the perspective of multiple disciplines.In PBL, the whole process from assigning a driving question or a problem to solve through students´ work in groups in solving the problem and looking for the answer to the question up to the final results represented by a product and sharing the results with a community, is usually referred to as project work.The project end product may involve constructing and sharing a physical or intellectual artefact of some kind.It can be in the form of an oral presentation, performance, written report, poster, brochure, webpage, physical models, objects using 3D printers, games, plays, simulations, computer programs, photographic exhibitions, short movies, audio recordings of music or podcasts, other media productions, etc.

STEM related projects to support inquiry enhanced by digital technologies
In solving authentic problems or answering driving questions, students apply and combine knowledge and skills from various STEM subjects, e.g.knowledge of physics can help to explain the principles of modern hardware, various phenomena connected with physics, chemistry or biology can be described by models applying knowledge of mathematics, skills to process and analyse data is closely connected to computer science and informatics´ skills in working with data, coding and programing, etc. Teaching science offers many opportunities to study interesting real-life phenomena with the help of digital technologies.As also stressed by Krajcik and Shin [9], the framework of the key characteristics of PBL [12] involves also the use of technological tools.The authors emphasize that science education should model the importance of computer aided technology in modern scientific research.Learning technologies constitute an important scaffold to students to manage the project activities.Specific group of technologies are digital technologies used as a scientific research tool.These are tools used to do scientific measurements and observations (various sensors, digital microscope, etc.) as well as modelling tools to develop scientific computer models.They can help in collecting data with the help of various sensors, then analysing and data processing and also mathematical modelling of observed phenomena using various programming platforms.In the following paragraphs we present project ideas that can be implemented at the upper or lower secondary level in cooperation of science, mathematics or informatics teachers.They were conducted in COACH [13], however, any other available platforms can be used.

Human Body Projects
Human body offers various ideas for students' project work.They can involve different physical and biological aspects of human body.

How can the rate of breathing and heart rate be affected?
Students answering this driving question are expected to investigate different breathing patterns in various situations, such as rest or during or after exercise.They collect data of air temperature during inhalation and exhalation to analyze differences in breathing rates.In addition, they can design a model of lungs using simple tools and collect data about pressure changes inside the bottle while reducing and increasing the bottle volume (figure 1,2).Inhalation and exhalation modelled with the help of the bottle (rib cage) and a pair of balloons (lungs) can be monitored also with the help of spirometer that measures real airflow rate of a person during the breathing cycle.Students can also investigate the relationship between physical activity and heart rate by monitoring heart rate during various activities such as running, cycling, jumping, weight lifting.They can use an available heart rate sensor.Moreover, students can analyze an electrocardiogram diagram (figure 1), to study heart rate diagrams, and their phases, such as P wave, QRS complex, T wave and U wave using also knowledge of biology and medicine.The project needs understanding of the concept temperature, volume and pressure, interpretation of data represented by a diagram and basics of human physiology connected with breathing and heart rate.The end product may involve a written report of analysis and interpretation of experimental results as well as an artefact of lungs' model.

How do we move? 4.2.1. How do different parts of human body move?
In this project, students can explore motion of different parts of their body using videomeasurement.They collect data by tracking selected points on the video of a walking or jumping person that students can record beforehand.After that they analyze diagrams of position of selected moving body points to interpret the specific patterns and conclude that the body motion is rather complicated (figure 3).The project end product may involve results of videomeasurement and their analysis and interpretation in a written report.

How many steps do we take in a day? Can you design your own pedometer using mobile phone?
Another option is to study the body motion using mobile phones.In this project students are expected to explore what sensors are available in their mobile phone and which sensor would be the most appropriate to study motion.Students familiarize themselves with the properties of accelerometer and analyze the data it provides.They can see that three components of acceleration are displayed.The values are changing periodically during walking.The best way is to calculate the magnitude of acceleration  = √(  2 +   2 +   2 ).When monitoring acceleration, it is important to decide where to place the mobile phone in order to count the number of steps accurately.
Students are expected to design a simple application using a programming platform -MIP App Inventor [14] in this caseto record acceleration data.The application calculates the acceleration magnitude (figure 4, left).The diagram needs to be analyzed in order to identify peaks that indicate a step.For accurate step detection the threshold value needs to be adjusted.Then a step counting algorithm is developed.It calculates number of events when the acceleration exceeds the threshold value in a certain direction (figure 4, right).This way the final project producta pedometer is designed.This project represents a complex task, requiring understanding the concept of acceleration, interpretation of data represented by a diagram, algorithm design and programming.The application can serve as a starting point for other STEM projects., e.g. to design a digital trainer that counts the number and frequency of squats or moreover, it could be developed to a tool that can diagnose various movement disorders, such as limping or tremors of body or limbs.

Motion projects
The motion projects can involve investigation of motion of sportsmen or persons performing specific or interesting kind of motion, such as sky or scuba divers or bungee jumpers.They involve motion in specific environments like air or water.Before they start they need to be sure that their jump or dive is safe.Understanding of physical laws and human physiology is crucial to ensure a safe experience.

How does sky diver move and what affects his safe dive?
In this project a group of students can look for the answer from different perspectives.They can study the motion and its physical principles.In order to predict how such a diver moves students can develop a mathematical model of his motion.For this they need to understand the concepts of gravity, Newton's laws of motion, air drag and basics of aerodynamics.Mathematical model can be designed in various programming platforms, e.g.professional, such as Python [15] or specialized school learning environments, such as COACH [13] and its modelling platform.The latter one enables to create models in a text or graphical mode.If the differential equation describing an investigated phenomenon or a process cannot be solved since it is far beyond the students' knowledge, numerical methods can be applied.In this case, the model calculates the change of a variable over small time steps when the rate of change of this variable can be considered constant.In figure 5 the model of a skydiver in text mode developed the described way can be seen.The skydiver falls from the height of 3000 m firstly in a bellyto-earth position achieving the speed of 55 m/s and later he opens a parachute that results in the terminal speed of 5 m/s that enables safe landing [16].The model enables to predict the results for different model parameters, e.g.smaller parachute cross-sectional area can lead to much higher terminal speed of 13 m/s that can be quite dangerous to land.
Both models can be simulated for different parameters in order to predict how the system behaves, however students need to be aware that they are still simplified models that did not capture the complexities of real-world diving scenarios.

Other motivating motions projects
There are many other motions that can attract students' attention and so that can be used for project work.During a bungee jump, the jumper descends with the belief that the rope stops him.Students can investigate his motion in detail answering questions, e.g.what does his motion look like?What properties should the rope have?What is the g-force experienced by a jumper?How is the body affected by the g-force?What are the g-force physiological effects?Students can design a mathematical model of the bungee jumper motion that needs understanding of the concept of gravity, elastic force and Newton's laws of motion.They can even design a physical model using a weight suspended on a rubber string with a force sensor and a motion detector and measure and analyse position and force acting on the weight during the fall (figure 8, left).Skywalk as another adrenaline attraction can be a motivating example for the project assignment.The skywalker walks on a tightrope at great height, usually between two buildings.In the design and construction of skywalks a lot of physical principles come into play.Safe skywalking is connected with balance, tension in the rope, friction between the footwear and the rope as well physiological aspects (muscular strength, vestibular and cardiovascular system, etc.).One of the driving questions can be: What properties does the rope need to have in terms of tensile strength?This question needs to analyse forces acting on the rope during skywalking.Students can design a simple model using a rope stretched between two stands with a weight in the middle with two force sensors.They can see that in certain cases the components of the skywalker weight may exceed his own weight (figure 8, right) [18].Other examples for project work may involve motion of various sportsmen, such as high or long jumper, basketball player jumping up towards the basket, diving from a platform or springboard.An example of a driving question can be connected with the motion of the centre of mass.Students can collect data with the help of videomeasurement.They can measure the position of the centre of mass for parts of the body with the known relative mass to calculate the centre of mass of the sportsman body and monitor its motion during the jump.

Conclusion
The project-based learning represents one of the active learning strategies that requires and enhance deep understanding and critical thinking through students' active engagement in solving real-life problems.In this paper we have explored the main principles and benefits of PBL also pointing to the benefits of digital technologies that can enhance PBL.We have presented a series of ideas for the project work that integrate different subject areas and develop interdisciplinary knowledge and skills.They utilize digital technologies to support experimentation (sensors) or modelling (various programming platforms).When working on projects connected with such complex problems, learners develop deeper understanding of the relevance of their education in real-life situations.When implementing PBL, teachers also must be aware of some challenges such as the level teachers' guidance and support, time management, and also assessment strategies.For successful implementation teachers' professional development is important.In the near future we plan to compile the project ideas with examples of the project outputs as well as teacher training sessions to provide teachers with the project ideas and implementation scenarios.

Figure 1 .
Figure 1.Diagrams of breathing and heart rate at rest (left) and after exercise (right).

Figure 2 .
Figure 2. Model of lungs and pressure measured inside bottle.

Figure 3 .
Figure 3. Diagrams of x and y position coordinates of left and right foot and knee during walking.

Figure 4
Figure 4 Acceleration data during walking (left) and threshold settings (right).

mFigure 8
Figure 8 Experimental results of position and force acting on the falling weight (left) and the experimental setup of the skywalker model with concrete results (right).