Does handwriting on a tablet screen affect students’ graphomotor execution? A comparison between Grades Two and Nine

Highlights

• Does handwriting on a tablet screen with a plastic tip affect students’ movements?

• We compared graphomotor execution on tablet and on paper in Grades Two and Nine.

• The tablet surface modified graphomotor execution differently according to grade.

• Segment calculation was disturbed in Grade Two, changing pause durations.

• Trajectory control was hindered in Grade Nine, changing pressure and movement speed.

Abstract

We sought to ascertain how handwriting with a plastic-tipped pen on the screen of a digital tablet affects graphomotor execution in students, compared with handwriting on paper with a ballpoint pen. We predicted that the modification to propriokinesthetic feedback induced by the screen/plastic tip combination would differently disturb younger and older students, who rely on perceptual feedback either to form letters (former) or to adjust movement execution (latter). Twenty-eight students from Grades Two and Nine were asked to handwrite the alphabet and their names and surnames under the two conditions. Kinematics were recorded using the tablet, controlled by Eye and Pen software. Results showed that handwriting on the tablet surface with a plastic-tipped pen primarily affected pen pauses in the second graders and pen movements in the ninth graders, suggesting a disturbance in segment trajectory calculation in the younger participants and reduced control of muscular adjustment in the older children.

Introduction

The advent of new technologies in schools means that students are now having to write with different tools in different media, including keyboards, virtual keyboards (tablets), and pen or fingers on a tablet surface, and no longer just with pen/pencil on paper. While this new technological reality may arouse fresh interest in writing (Clark and Dugdale, 2009, Karsenti and Collin, 2013), it does not necessarily make the activity itself any easier. For example, keyboarding is less efficient than handwriting in at least three areas (for a summary, see Caporossi and Alamargot, 2014, Mangen and Velay, 2010, Matthewman and Triggs, 2004). (i) Keyboarding requires frequent shifts of attention between the screen and the keyboard, an aspect that does not exist in handwriting. In addition, with handwriting, the text is produced at the very place where the motor action is performed, so the writer can simultaneously consider the letter’s formation and its textual context (Caporossi & Alamargot, 2014). (ii) Second, using readymade letters in keyboarding does not involve any graphomotor processing, unlike handwriting. The writer’s task is therefore limited to spatially locating the specific letters on the keyboard and pressing the corresponding keys (Mangen & Velay, 2010). This difference in motor execution has an effect on reading, as the additional motor encoding that occurs during letter formation has been shown to promote the recognition of these letters, both in kindergarten children (Longcamp, Zerbato-Poudou, & Velay, 2005) and in adults (Longcamp, Boucard, Gilhodes, & Velay, 2006). (iii) The use of a keyboard can prove to be a costly alternative for children, as they consume cognitive resources searching for the keys they have to press, at the expense of written production. By comparing the handwriting and typing fluency of 300 children aged 4–11 years as they copied out a sentence, Connelly, Gee, and Walsh (2007) demonstrated the superiority of handwriting, regardless of age. In a second study with fifth and sixth graders, the authors showed that keyboarding can be as much as two years behind handwriting in development. Only students who have received keyboard training (i.e., touch-typing instruction) seem to benefit from the use of word processing software (see also Christensen, 2004, Rogers and Case-Smith, 2002).

This series of examples linked to the use of a keyboard clearly shows that while technology can provide new and stimulating tools for writing, it can also impose new cognitive constraints that are not immediately perceptible. There is a similar problem when children use digital tablets in class, writing on the screen with a plastic-tipped pen. The few studies to have observed the impact of tablet use on writing have focused mainly on the new learning methods offered by interactivity (Berninger et al., 2015, Jolly and Gentaz, 2013). The question of graphomotor constraints introduced by the particularly smooth tablet surface does not seem to have been considered, probably because this tool has only very recently been introduced into the classroom. Nonetheless, we all seem to have difficulty writing on a smooth and slippery surface, such as when we sign our name on the back of a credit card (Wann & Nimmo-Smith, 1991). In the same way, writing with a plastic-tipped pen on the glass surface of a tablet produces a sensation of sliding over a slippery surface, which suggests that the fine motor control required for adjusting pen movements is disturbed.

It therefore seems timely to analyze the effects of screen surface on handwriting, by comparing the two handwriting media (i.e., paper and screen). Moreover, as handwriting control develops with age, notably with the mastery of motor programs at around 9 or 10 years of age, these possible effects probably vary according to the student’s level of development.

Handwriting movements are complex, and their mastery takes time. Assuming that handwriting acquisition begins formally at school at around 5–6 years, proficiency in handwriting is not definitively acquired before 14–15 years (Accardo et al., 2013, Blöte and Hamstra-Bletz, 1991, Rueckriegel et al., 2008, Ziviani and Wallen, 2006). During this developmental period, movement control shifts from a retroactive mode, based on the interpretation of sensory information (visual and propriokinesthetic feedback), to a proactive mode, based on central motor programs. Elaborated for each letter, these programs generally emerge at around 9–10 years (Blöte and Hamstra-Bletz, 1991, Chartrel and Vinter, 2006, Chartrel and Vinter, 2008, Schmidt and Lee, 2005, Vinter and Chartrel, 2010, Zesiger, 1995) and provide the instructions needed for the motor control system to produce integrated movements (Paillard, 1990, Ziviani and Wallen, 2006). It is only at around 14–15 years that motor programs become completely automated (Ajuriaguerra et al., 1971, Rueckriegel et al., 2008).

Before 9–10 years of age and the acquisition of motor programs, handwriting is slow and laborious. Considerable pressure is exerted on the pen, reflecting significant muscle tension, as well as the use of the shoulder and elbow to write (Bara and Gentaz, 2011, Chartrel and Vinter, 2004). The letters children form are often large, and have an irregular or rough appearance. The handwriting process is punctuated by pauses needed to calculate letter segments, based on sensory information. At the developmental level, Accardo et al. (2013) have shown that pause duration, which decreases significantly between 6 and 11 years, represents a sensitive indicator of changes in handwriting skills. Adopting another perspective, Paz-Villagrán, Danna, and Velay (2014) compared handwriting pauses in dysgraphic children aged 8–11 years with those of proficient children aged 7–9 years. These authors found that pauses that are either too numerous or too long are an indicator of dysfluency or poor handwriting. Beyond 9–10 years of age and the acquisition of motor programs, letter size, the amount of pressure exerted on the pen, and the frequency and duration of pauses between two segments decrease, while the speed, fluidity and legibility of letter formation increase (Accardo et al., 2013, Bara and Gentaz, 2011, Chartrel and Vinter, 2006, Chartrel and Vinter, 2008, Freeman, 1914, Meulenbroek and Van Galen, 1988, Vinter and Chartrel, 2010, Vinter and Zesiger, 2007, Zesiger et al., 2000, Ziviani and Wallen, 2006).

Thus, in young writers who have not yet acquired any motor programs, perceptual feedback plays an essential role in controlling handwriting movements (Ziviani & Wallen, 2006). Chartrel and Vinter (2006) showed that when they were blindfolded, students aged 8–10 years increased their propriokinesthetic feedback by putting more pressure on the pen and by making the letters larger and increasing pen speed. In adults, while the proactive control of movement limits recourse to sensory feedback, it does not totally replace it. Deprivation of visual and/or propriokinesthetic information has been shown to disturb movement kinematics. By asking university students to handwrite the letter sequences gegegeg and nenenen with and without visual feedback, Van Doorn and Keuss (1993) highlighted an increase in pressure, speed and letter size in the absence of vision. Increased pressure augments the contact with the paper, and thus the amount of proprioceptive information available (see also Van Doorn, 1992, Van Doorn and Keuss, 1992). The proprioceptive system therefore continues to contribute to the proper execution of motor programs and the effective production of movements in adults. By studying pointing gestures in deafferented patients, Bard, Turrell, Fleury, and Teasdale (1999) showed that the motor system has the ability to modify and correct erroneous trajectories simply on the basis of feedback loops. For these authors, proprioceptive information, alongside vision, has a special status among motor programs, ensuring the online regulation (adjustment) of the initial motor commands (see also Prochazka, 2011).

Regarding the adjustment of handwriting movement on the basis of propriokinesthetic information, paper smoothness has been shown to modify handwriting speed and pressure in experienced writers. When Chan and Lee (2005) asked adults to write a series of Chinese characters, they found that handwriting speed was slower for coated paper than for uncoated paper: writers needed to exercise more care and greater pen control to be able to write on the low-friction surface. A similar effect, but restricted to pen pressure, was demonstrated by Wann and Nimmo-Smith (1991). By asking adults to handwrite under conditions where pen (nylon tip vs. ballpoint tip) and paper (80 g/m paper vs. plain white paper) combinations produced different degrees of friction,¹ the authors showed that mean pressure decreases when writing on a high-friction surface and then increases on switching to a low-friction surface. Pen pressure was therefore modulated in order to maintain a more stable ratio between frictional forces and input forces. This result highlights the sensitivity that skilled adults appear to have to the kinematics of handwriting movement, and reflects an acquired strategy of increasing frictional forces in order to maintain the input–output dynamics at a level comparable to that of a normal, usual writing surface.

On the strength of studies with adults comparing paper textures and/or pen combinations (Chan and Lee, 2005, Wann and Nimmo-Smith, 1991), we can assume that, by modifying the propriokinesthetic feedback that students are accustomed to receive when writing on paper in the classroom, the smooth surface of a tablet screen, coupled with a plastic tipped pen, makes it more difficult for them to execute their handwriting movements. As far as we know, no such comparison has yet been undertaken among children, even for different roughnesses of paper. Furthermore, studies of the development of handwriting skills lead us to think that the modification in propriokinesthetic feedback, induced by the screen/plastic tip combination differently disturbs younger and older students (before and after motor program acquisition). Because younger students rely more heavily on perceptual feedback (retroactive visuo-propriokinesthetic feedback) to form letters, this type of change in the propriokinesthetic information presumably leads them to make longer pauses between segments in order to calculate their succession appropriately. By contrast, owing to their mastery of motor programs, more advanced writers (above the age of 9–10 years) can produce larger segments more fluently and without any significant pauses (Accardo et al., 2013). As the propriokinesthetic system therefore continues to contribute to the proper execution of motor programs and the ability to modify and correct erroneous trajectories (Bard et al., 1999), we reasoned that the change brought about by the screen/plastic tip combination would induce adjustments to pen movements. Older students would maximize their propriokinesthetic feedback by increasing the pressure they exerted on the pen and, possibly, the size of the letters they produced and, as a consequence (isochrony principle), their speed of movement.

To verify these hypotheses, we took several methodological decisions and precautions. In order to compare participants’ graphomotor performances in two types of handwriting conditions (pen on a sheet of paper and pen on a tablet screen), we (i) administered the written alphabet recall task and the name-surname task (Chuy et al., 2012, Pontart et al., 2013) to children from two different age groups (Grades 2 and 9) corresponding to the stages before and after acquiring handwriting motor programs; (ii) analyzed graphomotor performances, looking at letter legibility and handwriting kinematics (see Accardo et al., 2013, Mergl et al., 1999, Rosenblum et al., 2006, Rosenblum et al., 2006, van Galen and Weber, 1998).

To maximize the validity of our comparison of the two different writing conditions, we controlled for the effects of important factors such as handwriting tool, kinematic measurements, writing situation (posture, gesture, brightness), and friction between tip and surface. (i) The magnetic pen that had to be used with the tablet was the same size and shape as the pen that is commonly used in the classroom. It did not induce any particular difficulties with pen grasp, even among the younger students. (ii) To be able to compare handwriting kinematics on paper and on the screen, it was vital to use the same screen tablet and pen each time to preserve the digitizing rate and sensitivity. This is why we decided to place the sheet of paper over the tablet screen in the paper condition. Because the magnetic grid of the digitizing screen tablet is able to detect the presence of the pen even when it is in the air (up to about 1 cm from the surface), the addition of an ordinary sheet of paper (without any magnetic component) did not interfere with the tablet’s sensitivity and its ability to detect pen movements. To allow the magnetic pen to actually write on paper, the plastic tip of the pen (used for writing on the screen) had to be removed and replaced with a ballpoint tip. (iii) The decision to place the sheet of paper on the tablet had the added advantage of putting participants in exactly the same postural situation (body position, room for arm and gestural movement) and limiting the difference in brightness (owing to the relative transparency of the sheet of paper). Moreover, in order to control the amount of information displayed to participants and the amplitude of their writing movements in the two conditions, the size and location of the writing zones on the screen were replicated on the sheet of paper. (iv) To ascertain the effect induced by the surface and the pen tip, we first assessed the static friction effect between tip and surface. To do so, like Wann and Nimmo-Smith (1991), we used an articulated arm that held the pen on the surface and constrained its path. The translational force exerted on the pen to move it was generated by a 40 g load, while the pressure exerted on the pen was varied by adding weights to the pen (10, 20, 30 or 40 g) (see Fig. 1).

Measures of pen movement speed (for 22 cm of translational motion) were repeated under 16 conditions (4 loads × paper/screen surface × ballpoint/plastic tip). As shown in Table 1, results clearly indicated that the screen surface, when using a plastic tip, was dramatically smoother, generating, for the same translational force, a higher pen movement speed (mean: 47.27 cm/s) than the 80 g/m paper surface, when written on with a ballpoint tip (mean: 5.18 cm/s). This difference remained however much pressure was exerted on the pen.

It should be noted that the paper/plastic tip pairing induced such high friction that the 40 g weight did not generate any translational motion, however little pressure was exerted on the pen.