Sahito, Waqas Ali 10MSIT22 Supervisor - Prof. Dr. Zahid Hussain Abro creator Department of Information Technology text Nawabshah QUEST 2014 monographic 52p, : ABSTRACT The online information is steadily increasing More online course are now being offered by many universities worldwide. Publishers are releasing more online books and journals. Consumers are accessing online news, weather forecast, and product information daily. Therefore, the examination of the factors that influence the readability of online text is very important. Most of the time people prefer using Tablet PCs for onscreen reading. The foremost results of a prescribed experiment about onscreen text line lengths on Tablet Pc will be presented in the research. Efficiency is defined as a combination of reading speed and accuracy. The experiment examined the possessions of four different line lengths i-e 30 CPL (characters per line), 60 CPL, 90 CPL and 120 CPL. Seventy five people between the age of 20 and 40 participated in the experiment. The participants were the students and the teachers of the university. This usability test was conducted in university class rooms and office environment. The experiment was based on four age groups. All the groups had to read four different texts with an average line length that will vary by considering the devices. The texts contained substitution words which are pronounced similarly with slight difference which were to be detected by the reader in order to measure the reading accuracy. The previous work done in this area was on comparatively larger screen like computers and laptops, but when we are going to read the text on smaller screen like Tablet PC. The results of the usability test were calculated for individual user, group wise and overall for all the participants. Moreover on the usability test results like reading speed and accuracy, the readers were asked to individually vote on their reading experience. The results show that 90 CPL is better for online reading on the Tablet PC. For the Publisher to publish the e-books in the recommended CPL and result can be very useful for e-book reading. https://tinyurl.com/37exfbne https://tinyurl.com/37exfbne