NoSQL data models such as document databases and wide-column databases have gained popularity in industry and education in the last two decades. The database design principles and query languages of different NoSQL systems differ from those of the relational model and SQL, which can cause challenges in transitioning from relational systems to NoSQL systems. In this mixed-methods study, we explore the challenges novices experience with database design and querying with two NoSQL systems: MongoDB and Cassandra. Our results show that NoSQL database design is perceived more difficult than relational due to access-pattern-first design patterns, old habits, and the limits imposed by database distribution. Querying, however, is not perceived as more difficult or easier due to similarities of query languages to previous experiences with SQL and programming. These results are applicable in the classroom in determining the teaching order of novel data models, and in focusing teaching on the challenging aspects in document and wide-column databases.

Abstract Error messages are one of the primary ways software developers communicate with database management systems in SQL query writing tasks. Even though reading and interpreting error messages is a significant part of a software developer’s work, the error messages of SQL compilers have received criticism in terms of readability and their perceived detrimental effects on user experience. Consequently, redesigned SQL error messages have also been proposed to tackle the problems in current error messages. In this study, we examine the effects of enhanced error messages on query writing from several perspectives. The results indicate that when compared to PostgreSQL error messages, the enhanced error messages facilitate faster error fixing, as well as perceived benefits in error finding and error recovery confidence. Our results are applicable in industry, where development time is of significant importance, as well as in educational contexts, where user experience, user confidence, and perceived support in learning play an important role.

Reading and interpreting error messages are significant aspects of a software developer's work. Despite the importance and prevalence of error messages, especially for novices, SQL compiler error messages from various relational database management systems have seen limited development since their inception. This lack of progress may stem from the fact that it is not well-understood what constitutes an effective error message. With data from 568 participants across three student cohorts, we investigate whether novel SQL error message design guidelines can explain success in fixing SQL syntax errors. The results indicate that some of the guidelines indeed serve as building blocks toward more effective SQL error messages for novices. However, error messages that adhered to certain guidelines showed inconclusive or negative results. These findings can be applied to iterate on SQL error messages in SQL learning environments or SQL compilers.

Driver distraction by smartphone use is a major contributor in traffic accidents. Context-sensitive driver (in)attention monitoring and warning systems might mitigate the associated risks. However, few naturalistic studies are yet available on the effects of such systems. In this paper, utility of context-sensitivity in inattention monitoring was studied by a smartphone-based context-sensitive distraction warning system. The warnings were based on driver's phone use and the attentional demands of the upcoming traffic environment. The system's effects on 26 heavy smartphone users’ phone usage and acceptance were analyzed after a within-subject naturalistic study with 12 weeks of control (warnings off) and 12 weeks of interventions (warnings on). The system decreased odds that the drivers would touch their smartphones in reminder areas that were defined a priori as high demanding for attention. Against expectations, the system had no effect in urban road environments. The drivers reported that they had paid more attention to traffic because of the system and that the warnings were acceptable and useful, even if annoying. Similar systems’ safety effects should be further studied. No eye-tracking or driving performance measures were collected and thereby it is questionable if there was a true positive effect on participants’ attention. However, the findings suggest that (in)attention warning systems might benefit from adaptation of the warnings to the upcoming driving demands. The findings can be utilized for the development of proactive and context-sensitive (in)attention monitoring and distraction mitigation systems.

Software developers use a significant amount of time reading and interpreting error messages. However, error messages have often been based on either anecdotal evidence or expert opinion, disregarding novices, who arguably are the ones who benefit the most from effective error messages. Furthermore, the usability aspects of Structured Query Language (SQL) error messages have not received much scientific attention. In this mixed-methods study, we coded a total of 128 error messages from eight database management systems (DBMS), and using data from 311 participants, analysed 4,796 queries using regression analysis to find out if and how acknowledged error message qualities explain SQL syntax error fixing success rates. Additionally, we performed a conventional content analysis on 1,505 suggestions on how to improve SQL error messages, and based on the analysis, formulated a framework consisting of nine guidelines for SQL error message design. The results indicate that general error message qualities do not necessarily explain query fixing success in the context of SQL syntax errors and that even some novel NewSQL systems fail to account for basic error message design guidelines. The error message design framework and examples of its practical applications shown in this study are applicable in educational contexts as well as by DBMS vendors in understanding novice perspectives in error message design.

Modern database management is often faced with a high number of concurrent end-users, and the need for database distribution to ensure fault tolerance and high throughput. To flexibly address these challenges, many modern database management systems (DBMS) provide highly automated and effortless, i.e., highly usable database distribution, deployment, and maintenance. However, the usability considerations are yet to extend from the aforementioned DBMS features to query language compilers. In this study, based on participant answers (N = 157), we compare the error message qualities of four modern DBMSs (CockroachDB, SingleStore, NuoDB, and VoltDB) using one objective and three subjective metrics. Our results show that some of the DBMSs provide the users with more useful error messages, even though many of these error messages violate even the most basic usability guidelines. These results (i) are applicable in further developing the usability aspects of query language compilers, (ii) provide a timely effort of bridging the gap between human-computer interaction and query language compilers, and (iii) offer suggestions on teaching novices, who require emphasized support in query formulation.

The database and the database management system (DBMS) are two of the main components of any information system. Structured Query Language (SQL) is the most popular query language for retrieving data from the database, as well as for many other data management tasks. During system development and maintenance, software developers use a considerable amount of time to interpret compiler error messages. The quality of these error messages has been demonstrated to affect software development effectiveness, and correctly formulating queries and fixing them when needed is an important task for many software developers. In this study, we set out to investigate how participants (N=152) experienced the qualities of error messages of four popular DBMSs in terms of error message effectiveness, perceived usefulness for finding and fixing errors, and error recovery confidence. Our results show differences between the DBMSs by three of the four metrics, and indicate a discrepancy between objective effectiveness and subjective usefulness. The results suggest that although error messages have perceived differences in terms of usefulness for finding and fixing errors, these differences may not necessarily result in differences in query fixing success rates.

Three text entry methods were compared in a driving simulator study with 17 participants. Ninety-seven drivers' occlusion distance (OD) data mapped on the test routes was used as a baseline to evaluate the methods' visual distraction potential. Only the voice recognition-based text entry tasks passed the set verification criteria. Handwriting tasks were experienced as the most demanding and the voice recognition tasks as the least demanding. An individual in-car glance length preference was found, but against expectations, drivers' ODs did not correlate with in-car glance lengths or visual short-term memory capacity. The handwriting method was further studied with 24 participants with instructions and practice on writing eyes-on-road. The practice did not affect the test results. The findings suggest that handwriting could be visually less demanding than touch screen typing but the reliability of character recognition should be improved or the driver well-experienced with the method to minimize its distraction potential.

This is the first controlled quantitative analysis on the visual distraction effects of audio-visual route guidance in simulated, but ecologically realistic driving scenarios with dynamic maneuvers and self-controlled speed (N = 24). The audio-visual route guidance system under testing passed the set verification criteria, which was based on drivers' preferred occlusion distances on the test routes. There were no significant effects of an upcoming maneuver instruction location (up, down) on the in-car display on any metric or on the experienced workload. The drivers' median occlusion distances correlated significantly with median in-car glance distances. There was no correlation between drivers' median occlusion distance and intolerance of uncertainty but significant inverse correlations between occlusion distances and age as well as driving experience were found. The findings suggest that the visual distraction effects of audio-visual route guidance are low and provide general support for the proposed testing method.