PurposeThis study aims to develop a measurement instrument, which involves four usability dimensions of efficiency, effectiveness, satisfaction, and learnability, as a way of assessing the usability of academic digital libraries.Design/methodology/approachTo generate measurement items, previous research related to usability frameworks, usability guidelines, and empirical usability tests was reviewed. The measurement instrument was then verified in terms of reliability and validity, empirically using data from 230 actual users of an academic digital library. To ensure the reliability of the instrument, internal consistency of measurements, measurement item reliability, and construct reliability were examined. Construct validity, which consists of convergent validity and discriminant validity, was also examined on the basis of confirmatory factor analysis using structural equation modeling.FindingsThe usability evaluation instrument suggested in this study comprises four dimensions: efficiency, effectiveness, satisfaction, and learnability, and three to four items were identified to measure each dimension.Originality/valueTo date, while many of the usability studies have relied on either experimental methods or inspection methods, few studies have been conducted to identify evaluation measures that can assess the usability of a digital library from a survey method. This study is one of a few studies to develop a measurement instrument tailored to academic digital library environments.

The expansion of the social computing environment as a new basis for socioeconomic activities could enhance the quality of life of older adults, but also it could make the problem of digital divide more serious. In this study, the research directions and agenda of social computing for an aging society are presented, which have two major directions: basic study and applied study. Regarding human aspects in social computing mainly dealt with in the basic study, existing research and related theories on cognitive characteristics, information usage patterns, and social network site use of older adults were examined. In the applied study, a study about the most effective contents application and interfaces through user needs analysis, usage context analysis, prototype design, and so on, was conducted. Those studies are discussed to develop applications on a PC platform, mobile platform, and IPTV platform targeting the older adults population.

Purpose: Unplanned conversion is sometimes necessary during minimally invasive liver resection (MILR) of hepatocellular carcinoma (HCC). The aims of this study were to compare surgical outcomes of planned MILR and unplanned conversion and to investigate the risk factors after unplanned conversion. Methods: We retrospectively analyzed 286 patients who underwent MILR with HCC from January 2006 to December 2017. All patients were divided into a MILR group and an unplanned conversion group. The clinicopathologic characteristics and outcomes were compared between the 2 groups. In addition, surgical outcomes in the conversion group were compared with the planned open surgery group (n = 505). Risk factors for unplanned conversion were analyzed. Results: Of the 286 patients who underwent MILR, 18 patients (6.7%) had unplanned conversion during surgery. The unplanned conversion group showed statistically more blood loss, higher transfusion rate and postoperative complication rate, and longer hospital stay compared to the MILR group, whereas no such difference was observed in comparison with the planned open surgery group. There were no significant differences in overall and disease-free survival among 3 groups. The right-sided sectionectomy (right anterior and posterior sectionectomy), central bisectionectomy and tumor size were risk factors of unplanned conversion. Conclusion: Unplanned conversion during MILR for HCC was associated with poor perioperative outcomes, but it did not affect long-term oncologic outcomes in our study. In addition, when planning right-sided sectionectomy or central bisectionectomy for a large tumor (more than 5 cm), we should recommend open surgery or MILR with an informed consent for unplanned open conversions.

This ongoing project investigated effectiveness of query reformulations using user-generated information retrieval diaries. This study is one of a few studies that employed a diary method and assessed query reformulation effectiveness directly from users' ratings. In addition, the pilot analysis investigated the effect of multiple factors on search results improvement, including query reformulation types, user domain knowledge, and familiarity with the system. The pilot analysis results reveal that the parallel movement type of query reformulations was the most effective in obtaining improved search results, while users' domain knowledge and familiarity with the system would not be associated with query reformulation effectiveness.

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