The purpose of this study was to examine if the interactivity of e-book has impacts on cognitive load
factors in reading and performing tasks with smartpad. the use of smartpad. In this study three types of
e-book format were tested: 1) PDF with a single column edition, 2) PDF with two column edition, and
3) app-book with swiping and link functions. Seventy-seven college students , male=35 and female=42)
were recruited as a paid participant. With the consideration of various screen sizes, two types of smartpad
were used: iPAD and iPAD-mini. As experiment tasks two activities were required to the participants: 1)
reading e-book and 2) finding specific information in e-book. As a result, a significant main effect was
found that the PDF formats were generally more effective than app-book format. However, no significant
differences were found by the screen size. Moreover, there was a significant difference between the levels of
activity , reading vs. finding information). Reading required less cognitive loads than finding information.
However, it was not for all of the cognitive load factors. This study concluded that simple design may be
a better principle for e-book design. It may not be necessary to consider the screen size to design and
develop e-book. Different types of interface design may need to be applied depending upon types of
activities.