Children are attracted to smartphones more than other household gadgets [1] and such a new form of media can affect their wellbeing [2]. Smartphones invoke curiosity and interest among children. By the age of 2 years, children can hold a smartphone firmly in their hands and scribble and draw using a simple drawing app [3]. Children explore different types of mobile apps as they grow up [4]. Mobile apps with age appropriate and engaging content and an interactive interface can be used to foster informal learning among young children [5,6]. However, Chau [7] found that many mobile apps marketed for children are not actually suitable for them. Mobile apps for children should have a user interface that takes into consideration the physical and cognitive capabilities of children [8], and use appropriate ways for providing instructions to children on how to use them [9]. Children acquire skills necessary for using mobile apps gradually as they grow up. If the capabilities of children belonging to different age groups are known to software developers, then they can develop suitable mobile apps for them. Ability to perform touchscreen gestures and follow in-app instructions are 2 important skills necessary for using mobile apps. In this study, we evaluate these 2 skills of children.

Users interact differently with personal computers and smartphones even when they are using the same software, and their interaction with smartphones is strongly influenced by their ability to perform various touchscreen gestures. Preliminary studies found that 2- and 3-year-old children can perform gestures like tap, slide and flick [10], while 4- to 6-year-old children can perform more complex gestures like drag and drop and pinch and zoom [10,11]. Nacher et al. [12] experimented with interface designs that allow children to perform touchscreen gestures with more ease.

Mobile apps typically use text, audio and animation to provide instructions to users on how to use them. Young children cannot follow in-app prompting techniques used by mobile apps and need an adult to guide them when using mobile apps. Hiniker et al. [13] observed that children start following the instructions provided by mobile apps around the age of 5 years and can then operate a smartphone alone. McKnight and Fitton [14] observed that children often have problem in understanding the language of the instructions provided by mobile apps.

The objective of our study was to understand the ability of 2- to 8-year-old children to perform touchscreen gestures and follow in-app prompting techniques.

Children aged 2 and 3 years could hardly perform any touchscreen gesture (Fig. 2). Only 27% children in this age group could tap on an intended place on the touchscreen. Alternatively, children aged 4 to 6 years were more proficient in using smartphones. A majority of children in this age group were able to perform simple touchscreen gestures. Among the children in this age group, 57% could tap on an intended place on the touchscreen, 37% could tap on an object moving across the screen and 20% could tap and hold at an intended place on the touchscreen. It was observed that most children learn to perform single-finger touchscreen gestures by the age of 7 years. Children aged 7 and 8 years could perform tap (83%), tap on a moving object (73%), tap and hold (60%), slide (40%), and drag and drop (30%). However, only a few children in this age group could perform 2-finger touchscreen gestures like pinch and zoom (13%) and pinch and rotate (10%).

Children aged 2 and 3 years could not typically follow any in-app prompting technique (Fig. 3). They can use an app only if someone explained it to them in person. However, children typically develop skills to follow in-app prompting techniques by the age of 4 years. A majority of children aged 4 to 6 years (63%) could follow one or more in-app prompting techniques. The most difficult prompting technique that children in this age group could follow was instructions in audio format (17%), instructions in video format (17%) and instructions using animation (37%). Almost all children (97%) aged 7 and 8 years could follow one or more in-app prompting techniques. The most difficult prompting technique that the children in this age group were able to follow was textual instructions (17%), textual instructions on-the-fly (17%), instructions in audio format (20%), instructions in video format (33%) and instructions using animation (10%).

We observed a significant difference between the number of touchscreen gestures that the children could perform and the number of prompting techniques that they could follow (F= 544.0407, P<0.05). However, we did not observe a significant (P>0.05) difference in the number of touchscreen gestures that could be performed by female and male children in any of the 3 age groups (Table 1). Similarly, we did not observe a significant (P>0.05) difference in the number of prompting techniques that could be followed by female and male children in any of the 3 age groups (Table 1).

Nowadays, parents and teachers often use smartphones to entertain and educate young children [15]. However, smartphones can facilitate child development only if the apps are designed suitably [7]. Moreover, children should use mobile apps in conjunction with their academic activities and play in the physical world.

Abdul Aziz et al. [10] and Hiniker et al. [13] studied the ability of children to use mobile apps and a foreknowledge of their findings help ed us to design our study. We designed our experiment to be more systematic and involved more children. We observed that children learn to perform various touchscreen gestures and follow in-app prompting techniques between 4 and 8 years of age. Two- and 3-year-old children typically require help from their caregivers for using mobile apps. Apps for children in this age group should work with little intervention from the children and may ignore accidental touches on the screen. Four- to 6-year-old children can use mobile apps independently. However, using apps meant for children in this age group should require only simple touchscreen gestures like tap and slide. Instructions may be provided through animation which can be understood by a majority of children in this age group. More sophisticated mobile apps may be developed for 7- to 8-year-old children. Seven- and 8-year-old children can perform single-finger touch screen gestures and follow instructions provided in the forms of animation, and audio and video clips. We observed that some children could perform more touchscreen gestures and fol low more prompting techniques than other children of their age. We found that children who use mobile apps frequently could perform more touchscreen gestures and follow more sophisticated prompting techniques. The ability to perform touchscreen gestures or follow prompting techniques is not an appropriate measure of children’s development.

Smartphones may be used to foster child development. However, the apps to be provided to children should be developed according to their physical and cognitive capabilities. Children learn to perform single-finger touchscreen gestures and follow nontextual prompting techniques between 4 and 8 years of age. Apps for children aged 8 years or less should not use textual prompts and using such apps should not require performing multifinger gestures like pinch and zoom and pinch and rotate.