The incorporation of information and communication technology (ICT) in the education sector has revolutionized learning techniques, and the way information is passed from the teachers/lecturers to the learners; as well as the way both teacher and learners interact with the learning materials.
This has led to the emergence of electronic learning and its subsequent consolidation with digital learning to produce what has so far been the dominant form of learning technology that powers educational technology in the developed world – E-learning, which incorporates both online and classroom learning.
Like traditional learning, electronic learning requires the teacher/lecture to present the information being discussed on a large display, which allows for a visible representation of knowledge in the form of data (text) and images.
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From Blackboard to Whiteboard
Initially, this large display was the blackboard. It was replaced in the 1950s by the whiteboard.
At this time, both the blackboard and the whiteboard were known as marker boards, wipe boards, dry-erase boards, and dry-wipe boards (we now also have sophisticated paint mixtures to create dry-erase walls).
They have remained popular due to their ability to provided a smooth surface where non-permanent markings could be made, and erased easily.
Even so, the whiteboard has a white surface that is smoother and glossier than that found on the black surface of the blackboard.
Moreover, whiteboards require one to use a marker pen instead of a blackboard chalk, and it for this reason that it is known as a pen-board.
Uniquely, the markings in these early whiteboards were erased by damp cloths, while blackboards were wiped clean by dry cloth dusters. This created a challenge as some markings remained visible after erasing, and this led to the development of dry-erase markers in 1975 which allowed for better erasure of whiteboard markings.
Evolution of Whiteboards
In the late 1980s and early 1990s, the whiteboard had become a popular fixture in offices. This was also the era of the computer and internet revolution; and contemporaneous innovation led to development of collaborative applications called whiteboards which used the white space of text applications as a canvas where users could write, edit, and share information.
In the 2000s, the touchscreen which combined an input device with the computer visual display into a unified information processing system had been developed, and this allowed users to use their fingers as the mouse, as well as to press on the onscreen keyboard input information into the whiteboard applications.
Later, the capabilities to draw and write directly onto the touchscreen using a special type of pen allowed users to draw and write on whiteboards as natively as if they were doing it on a hardcopy paper.
In lecture halls and classrooms, the whiteboard needs to be large so that everyone can see the information. Because most teachers/lecturers used PowerPoint (PPT) presentations, it was convenient for them to connect the computer to an overhead projector which would project the computer screen onto a large fabric, whiteboard, or white wall surface, which served as the projection screen.
Even so, the user could only change the information on the projection screen by typing into the computer the required data. This led to research on how the lecturer/teacher could directly change the information in the projection screen without physically touching the computer.
This led to the development of an interactive display that allowed for direct human-to-computer interaction when the user touched, pressed, or typed data onto the projection screen; with the changes in the display being registered in the computer. This touch-sensitive display was then developed into the form factor of standard whiteboards, and hence the interactive whiteboard was born.
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Introduction to the Interactive Whiteboard
As described earlier, the interactive whiteboard (IWB) is basically a large interactive display sized to a whiteboard form factor.
They are two main types of interactive whiteboards; the standalone (or integrated) unit which is basically a large touchscreen computer, mostly all-in-one computers or a large format screen powered by a system-on-a-chip (SoC).
The connectable IWB that layers a touchpad on top of the projector screen to create an interactive board that allows for instructions and user inputs to be relayed to the computer via the projector.
In both types, the touch-sensitive display is virtually supported by a groupware (which is a collaborative software that allows for real-time editing of information) that is forked and developed from earlier whiteboard applications.
This makes the IWB to operate as a smart device, and hence its alternative designation, the smartboard. Outside the classroom and lecture halls, this smartboard can support collaborative brainstorming, as well as idea development in the workplace, besides allowing for digitalization of cooperative tasks and operations.
The fact that the IWB projects the desktop to the audience/learners means that what can be done on a computer, can be done on the IWB, including allowing lecturers/ teachers to save (lecture) documents, watch (educational) videos, and even show learners how to use computer programs (software).
This gives the IWB priceless capabilities for all-rounded learning as compared to the traditional whiteboards and chalkboards. In fact, the use of interactive whiteboards is advocated by the philosophy of education called constructivist pedagogy.
The computing model used to operate IWB is based on the classroom metaphor, and this allows the classroom environment to be implemented as the graphical shell (or graphical user interface [GUI]) that permits the user to operate the installed programs/applications.
The classroom metaphor means that learning tools found in the classroom environment, such as a protractor, compass, ruler, marker pen, and dry eraser, have virtual equivalents, such as the virtual protractor, virtual compass, and virtual ruler which is also found in the grid document used for drawing graphs; while the equivalents for the marker pen and eraser are the virtual keyboard, including its delete and backspace functions, and virtual drawing.
In terms of technological evolution, the interactive whiteboard defines the technological breakthrough that combined two educational tools; the marker-board, and the overhead projection screens (which consisted of a large screen and an overhead video projector), into a single interactive display that could perform the key functions of both tools.
This has also impacted its functionalization with the three tasks of the IWB being summarized as control, translation, and presentation.
Control means that the user utilizes the projection field to access and control a consumer-grade computer, usually a personal computer (PC). In connectable IWBs, the USB (universal serial bus) port, or the older serial port, of the PC allows for connection to the projector, while newer PCs allow for wireless connection.
Relatedly, IWBs allows user to write directly on the projection field, and these hand-written notes and drawings can be translated seamlessly into standard computer text and images, which can be saved; and this functionality is described as translation.
Regarding presentation, the IWB allows the user to start and control lecture presentations, usually PPT presentations; as well as perform real-time editing of such presentations as the IWB features complete emulation of keyboard and mouse functions, including click-and-drag and markup options.
IWB Application Layer
The application software of IWBs provide features and tools designed to maximize interaction, and this is the reason why one must consider the default application layer of an IWB before purchasing it.
This application layer allows for creation of virtual educational/learning documents and charts, including flipcharts, and also supports highlighter and pen options.
This layer also allows the user to capture texts, cursive writings, and images contained in a graphics tablet connected to an IWB.
Additionally, this layer contains the audience response system that allows for polling, quizzing, and capturing feedback from learners or audience. Besides, the learner response system (which can be forked into a classroom response system) is part of this application layer.
Shape recognition and optical character recognition software can also be added to this layer so that texts and images in scanned documents, including handbooks, can be converted and translated into refined shapes and standard computer texts.
Operationally, IWBs are categorized in two ways; based on location of projector, and based on operation principle. In IWBs, the device driver converts the projection field into a human-input device (HID).
This device driver is basically a program installed in the PC and controls another hardware – the projection field – by providing a software interface that allows for abstraction which ensures that information/data written on the projection field is translated as explained above.
This device driver sometimes comes bundled with a handwriting recognition algorithm. The device driver is normally bundled as part of the system software.
IWBs can be categorized into the following 2 types based on the positioning of the projector
Frontal Projection System
The projector is placed in front of the projection field (the whiteboard). It can be fixed on the whiteboard (and this is called short-throw projection), or positioned as an overhead projector.
This is found in most connectable IWBs. Its key merits include cheaper costs as compared to rear projection, easy installation, and simple cost-effective solution for beginners (or people unacquainted with IWBs). Moreover, the user can block the projection beam easily which cuts communication between the whiteboard and the PC.
Even so, it suffers two key demerits. First of all, the presenter can be distracted by the projector light. Secondly, the presenter can cast his/her shadow onto the projection field if (s)he blocks the projection beam.
This can be avoided if an ultra-short-throw (USTs) video projector is used. These demerits are also eliminated in the rear projection system
Rear Projection System
It is also called back projection as the projector is positioned behind the projection field. Even so, it is quite expensive and is rarely found in school environments, though it is very popular with corporate presentations.
Normally, this use extremely short-throw projection with a lens mounted directly behind the projection screen so as to magnify the projection images onto the projection field. Rear projection models are larger than frontal projection models, and in-wall installation is preferred over flush mounting onto the wall.
Sensing Technology and Operation Principles
Normally, IWBs come with preset modes depending on the available input options, with most featuring the pen mode (for cursive writing) and the cursor mode (for click-and-drag operations). This is made possible by the sensing technology that supports interactivity.
To maximize user convenience, the sensing technology is assisted by beam angulation. Beam angulation is possible because of the use of angle lens. More critically, the angle lens allows for raising or lowering of the display so as to accommodate audience of different heights, for instance, early K-12 learners.
There are different types of sensing technology with the main ones discussed below
This uses the resistance-modification principle that allows a touch-sensitive technology to be built into a dual-layer projection screen. This screen has 2 sheets – the flexible plastic sheet at the front and the rear hard/solid cover – that are separated by a hairline-thin air layer.
Both sheets are coated with resistive material. Pressing the flexible sheet by a finger or stylus causes it to be deformed and breach the air gap to touch the rear sheet, which is the conducting backplate, and this point of contact is electronically located and registered by the IWB as a mouse event/input.
This technology does not require special accessories, and is relatively easy to use, and accurate positing of mouse events can be achieved.
Expectedly, the screen surface is soft, and these types of projection fields are called soft boards, and they can be controlled manually and have low resistance to physical impact. On the downside, it lacks the right mouse button function, and not all soft boards make high-quality IWBs.
This uses an array (or web) of wires arranged into a neat pattern to create a sensory net. This sensory net is embedded in the projection board, and can interact with the coil fitted in the tip of the stylus.
In an active stylus, electric current – supplied by a battery or a wire connected to the IWB – runs through the coil; while in a passive stylus, no electric current flows through the coil.
The electrical signals produced by the sensory net create a magnetic flux which is altered by the magnetic flux in the coil of an approaching stylus tip, with close approach being detected as a mouse pointer hence giving the stylus mouse-over capabilities, and when the tip touches the writing surface, then the pen mode is activated.
Normally, the sensory net is placed between 2 hard plastic sheets with filling material keeping the net in place. The front sheet is covered anteriorly by an indestructible glass which serves as the writing surface.
This durable, hard writing surface gives the electromagnetic projection field the name hard board, and most benefit from a lifetime warranty.
This hard board can only be controlled by a special pen described above, and requires a software layer that allows the pen mode and mouse emulation to be translated into standardized computer data and images. Unlike the soft board, the hard board is more resistant to physical impact and this makes it ideal for incorporation into an IWB.
The aforedescribed hard board is called an active electromagnetic board. There is also a passive electromagnetic board in which the sensory unit is the electromagnetic coil in the stylus, while the hard board features tiny magnetic fibers arranged into a responsive magnetic mesh.
In these boards, wires create a sensory array that can detect touch. This array is based on the x-and-y axes of the cartesian plate, and hence touch location is identified in terms of x,y coordinates.
Specialized capacitive boards such as the Projected Capacitive IWB has an indium-tin oxide (ITO) grid, while newer forked models replace the ITO grid with transparent electrodes.
This uses ultrasonic positioning technology that can be supported by infrared light. Its mode of operation relies on computation of the time difference between light speed and sound speed, which is analogous to calculating the time lag between sighting a lightning and hearing the thunderstorm.
In the pure ultrasonic model, there are 2 ultrasonic transmitters positioned in two corners of the board, while the other two corners feature 2 ultrasonic receivers.
The transmitters cause ultrasonic waves to be propagated across the projection field, with these waves being reflected back when they reach the whiteboard borders.
When this field is touched by a pen or finger, wave propagation and reflection is suppressed, and this is detected by the receivers which precisely locate the point of suppression, with this positioning information being relayed immediately to the controller.
In the hybrid ultrasonic-infrared system, pressing the projection field suppresses wave propagation and reflection, which results in two signals being released – infrared light and ultrasonic sound.
The sound signals are detected by 2 ultrasonic microphones, and the time difference of when each microphone detected the sound signal is used to triangulate the position of the stylus.
Unlike electromagnetic and resistive membrane IWBs, ultrasonic technology allows for boards to be constructed from any material, as long as the writing surface is well-customized and adapted to use of active dry-erase stylus.
Dispersive Signal Technology
This is based on a unique form of wave interference called refraction whereby touch (or press) creates vibrations that causes bent waves to be propagated through a substrate.
These refracted waves are detected by sensors mounted at the corners of the projection field. These sensors operate as transducers that convert vibrational energy to electrical energy in form of electrical signals. Then, proprietary software algorithms perform digital signal processing to locate the touch point.
The touch surface is usually a glass substrate which allows vibrations to be radiated easily through it, and these vibrations produce bending waves.
This uses a projector with an inbuilt CMOS camera, and a supporting active infrared light pen. It was developed in 2007 by Boxlight.
The image projected is displayed in the projection field, and the pen can contact this projected image, with this contact position being triangulated with minimal error. Still, this technology lacks mouse-over capabilities.
Wiimote is a portmanteau of Wii and remote; and it shows that the Wii remote control fitted at the front with an infrared camera is the most critical component in this IWB. This allows the remote to function as the tracking device which detects light produced by an infrared pen.
This allows for positioning of the pen in the projection field. Even so, this technology cannot be used in an environment where it is subjected to direct sunlight.
This IWB combines electromagnetic and infrared technology into a unified optical technology called frustrated total internal reflection (FTIR).
It uses evanescent wave which is transmitted through layers of materials with different refractive index, which results in evanescent wave coupling that causes energy to pass from materials with lower refractive index to the material with the highest refractive index.
Even so, the spacing between the layers must be multiples of the wavelength of the wave (normally less than 10 wavelengths, and the lower the better).
In the IWB, a flexible, transparent surface allows light to be refracted and thereafter reflected internally in the display.
However, a finger press changes the surface uniformity of this layer, and this disrupts internal reflection which allows energy to escape from the surface as light which can be detected by cameras connected to image processing software whose algorithms allow for positioning and tracking of pointer movements.
The projection field of an IWB needs to be calibrated with a display image, usually formed by a sequence of crosses or dots. The user then selects these crosses or dots, and checks for their alignment with the desktop image in the PC.
This process is called orientation, calibration or alignment; and it ensures that the projection field symmetrically matches the desktop display, and this prevents distortion of images.
Automatic calibration using the Gray Code sequence was developed and patented by Mitsubishi Electric Research Laboratories.
An alternative method uses a light sensor in the projector that detects reflected light and uses it to calibrate the display through a process described as training which is based on computation of linear matrix transform co-efficients.
Another automated calibration technology uses a pen camera that detects the human-imperceptible images injected into the projected beam, and then abstracts their position information which is processed through a positioning algorithm that auto-calibrates the display.
IWBs can be divided into 2 types depending on installation; fixed, and portable IWBs. Fixed IWBs are fitted into walls in one of three ways: flush mounting, mounting onto wall brackets, and in-wall installation.
Portable IWBs are smaller than fixed IWBs, and they can be carried around the school, factory, or office. They are mounted onto portable mounts.
The key functional properties of a flat panel display are its picture quality (especially in standalone IWB), maximum image size, and image resolution; as well as audio support and corresponding options for choosing inputs and outputs for audio and video.
When considered as part of an IWB, the touchscreen capabilities gain a priority status as they determine how the flat panel display closely mimics the PC monitor display.
The key touchscreen capabilities considered are support for single-touch, dual-touch, and gesture recognition. High-quality and high-performance IWBs simultaneously support dual-touch and gesture, and depending on its size can accommodate 3 or more concurrent users.
The key PC display capabilities integrated into IWB displays are sampling rates, touch accuracy and cursor speed. Touch accuracy is simply how accurate the IWB recognizes a touch at the point where the projection field has been pressed.