A Pilot Study on Extending the SUS Survey: Early Results

The System Usability Scale (SUS) is a popular method to measure the subjective usability of a system, due largely to the simplicity and rapidity of both collecting and analyzing data. A drawback is that the SUS generates a single unidimensional usability score from 0-100. Several researchers have amassed larger datasets across multiple projects to allow for analysis on additional methods to glean insights from the SUS survey. Along these lines, we investigate the practical value of extending the SUS survey with additional items such as open text responses, and test underlying assumptions of how SUS results are interpreted. We found that while a lower SUS score does generally correlate to a stronger desire to modify the system, people generally want to make modifications to a system regardless of its usability. Further, we found that the amount of user feedback related to modifications to a system provided predicted subjective usability ratings.

Semi-automated stair climbing of a wheel hub-based patient transportation aid for emergency medical services

A novel approach for a patient transportation aid for emergency medical services bases on a wheel hub stair-climbing mechanism, which currently requires a manual adjustment relative to the stair edges. In this paper, an approach for an automation is presented which utilizes two distance sensors to characterize stairs and determine the relative position to them. A controller can then adjust the system’s position automatically. A user supervision concept copes with sensor inaccuracies or errors, resulting in a semi-automatic process. Within a formative usability study ( n = 11 n=11 users) the algorithm was able to reconstruct the stairs and drive the system neither falling down nor colliding with steps. The semi-automatic process reduced climbing time by 59 % and the participants reported a higher subjective usability compared to manual stair climbing.

Usability Evaluation of Slanted Computer Mice

Prevention of musculoskeletal disorders is supported by use of slanted rather than horizontal pointing devices, but user acceptance of the former may be compromised due to lower perceived ease of use. This study compares subjectively rated usability (N = 37) for three sizes of slanted computer mice and includes a horizontal small conventional device as a reference. For a random subset of the sample (n = 10), objective usability parameters were also elicited. Participants followed a standard protocol which is based on executing graphical pointing, steering, and dragging tasks generated by a purpose-built software. Subjective ratings were collected for each of the four pointing devices tested. The three slanted devices differed in size but were chosen because of an approximately similar slant angle (around 50–60 degrees relative to the horizontal plane). Additionally, effectiveness and efficiency were objectively calculated based on data recorded for the graphical tasks’ software for a random subset of the participants (n = 10). The results unveil small differences in preference in some of the subjective usability parameters across hand size groups. This notwithstanding, the objective efficiency results are aligned with the subjective results, indicating consistency with the hypothesis that smaller slanted devices relative to the user’s hand size are easier to use than larger ones. Mean values of weighted efficiency recorded in the study range from 68% to 75%, with differences across devices coherent with preference rank orders.

Is It Time to Go Positive? Assessing the Positively Worded System Usability Scale (SUS)

Objective: The goal of the research presented in this paper was to determine if the positively worded System Usability Scale (SUS) can be used in place of the positively and negatively worded standard SUS instrument for the subjective assessment of usability, and whether the results found here replicate those of Sauro and Lewis. Background: Sauro and Lewis’ previous study found no evidence that responses to SUS items differed across the standard SUS and the modified, positively worded version of the SUS when participants assessed websites. This study replicates and extends this work by examining a large number of different systems with larger sample sizes to add to the generalizability of previous findings. Methods: So that participants could retrospectively assess 20 products, the standard SUS was administered to 268 participants and the positive SUS to 698 participants. SUS scores were computed and the data analyzed using psychometric methods to explore how the two versions of the SUS differed. Results: The standard and positive versions of the SUS yielded similar SUS scores. In addition, both versions of the scale demonstrated evidence in support of reliability and validity. Conclusion: Either version of the SUS can be used with confidence to measure subjective usability. Furthermore, the scores generated from both versions of the SUS can be directly compared. Applications: In situations where cognitive load, participants’ spoken language, or item consistency with other surveys being given may be a factor, the positive SUS is a viable alternative to the standard SUS.

Integrating usability and social cognitive theories with the technology acceptance model to understand young users’ acceptance of a health information portal

The past decade has seen the proliferation of health information portals; however, consumer acceptance of the portals has proven difficult and rate of use has been limited. This study developed a consumer acceptance model by integrating usability and social cognitive theories with the technology acceptance model to explain young Internet users’ acceptance of health information portals. Participants (n = 201) completed a self-report questionnaire measuring model constructs after attending a usability testing with a typical health information portal. Results showed that the hypothesized model accounted for 56 percent of the variance in behavioral intention to use the portal and explained consumer acceptance well. Both subjective usability and application-specific self-efficacy served as significant antecedents in the model, while application-specific self-efficacy also moderated the effect of subjective usability on perceived ease of use. The findings can help practitioners with the design and implementation of health information portals and other health informatics applications in support of consumer acceptance.

Users’ Perception of their Satisfaction and Experience on a Mobile Cinema Application

A subjective usability evaluation was carried out on a mobile cinema application (GSC mobile cinema application) to evaluate the satisfaction and experience of its users. The evaluation was done in two areas: Politeknik Balik Pulau, Pulau Pinang and Kolej Poly-Tech Mara (KPTM) Alor Setar, Kedah. The rationale for the assessment was to evaluate the satisfaction and experience of users in terms of their reactions to the mobile application’s interface, terminology and information, application capability and general impression. Twenty volunteers participated in the study. Ten of these participants were at Politeknik Balik Pulau, Pulau Pinang and the other ten were at Kolej Polytech Technology Mara, Alor Setar. The findings indicate that the application’s interface was easy to use, simple, consistent, clear, operable, understandable, fast, error recoverable, learnable and enjoyable.

Usability Assessments of Mobile Applications as a Function of Geographic Location

Researchers recently demonstrated that subjective usability assessments of common products do not vary across geographic locations. That study did not directly address mobile applications, which are some of the most ubiquitous and geographically diverse systems in use in the United States today. To address this shortcoming, this article examined whether or not geographic location impacts the perceived usability of mobile applications by having 2,590 participants from different regions of the United States rate the usability of several mobile applications using the System Usability Scale. There was a lack of evidence to support statistically significant differences in usability scores across geographic locations for 95% of the mobile applications evaluated. This suggests that system usability assessments for mobile products do not differ across US locations. These findings further reinforce the idea that participants from any locale can be recruited for usability tests as long as all other critical demographic criteria are met.

Prototyping the Automated Food Imaging and Nutrient Intake Tracking System: Modified Participatory Iterative Design Sprint (Preprint)

BACKGROUND A total of 45% of older adults living in long-term care (LTC) have some form of malnutrition. Several methods of tracking food and fluid intake exist, but they are limited in terms of their accuracy and ease of application. An easy-to-use, objective, accurate, and comprehensive food intake system designed with LTC in mind may provide additional insights regarding nutritional support systems and nutritional interventions. OBJECTIVE The aim of this study was to conduct a multistage participatory iterative design sprint of a Goldilocks quality horizontal prototype for the Automated Food Imaging and Nutrient Intake Tracking (AFINI-T) system. Specific design objectives included the following: (1) identify practice-relevant problems and solutions through user-centered participatory design, (2) mitigate feasibility-related barriers to uptake, and (3) employ user-centered technology development. METHODS A 6-stage iterative participatory design sprint was developed and executed. A total of 38 participants and advisors representing 15 distinct roles (eg, personal support worker, nurse, and dietitian) were engaged in the design sprint. Subjective workload (Raw Task Load Index), subjective usability scales, and a modified Ravden checklist were used to assess project advisors’ perceptions of the AFINI-T system prototype compared with the current method of food and fluid intake charting. RESULTS The top priorities for this system were identified as the following: ease of use, high accuracy, system reliability, ease of maintenance, and requirement of integrating with the current PointClickCare system. Data from project advisors informed design decisions leading to a Goldilocks quality horizontal prototype of the AFINI-T system. Compared with the current food and fluid intake charting system, AFINI-T was perceived to have the following: less time demands (t10.8=4.89; P<.001), less effort (t13.5=5.55; P<.001), and less frustration (t13.0=3.80; P=.002). Usability ratings of the AFINI-T prototype were high, with a subjective usability score mean of 89.2 and the highest ratings on a modified Ravden usability checklist of “very satisfactory” for 7 out of 8 sections. CONCLUSIONS The AFINI-T concept system appears to have good practice relevance as a tool for an intelligent food and fluid intake tracking system in LTC. The AFINI-T concept system may provide improvement over the current system, and advisors are keen to try the AFINI-T system. This research gives tangible examples of how the sprint method can be adapted and applied to the development of novel needs-based application-driven technology.

Extraneous Factors in Usability Testing: Evidence of Decision Fatigue During Sequential Usability Judgments

Previous work has examined if cognitive fatigue caused subjects to negatively evaluate products on subjective usability measures but failed to find an effect. The authors suggested that methodological issues may have caused variance, which masked any experimental effect. This study tested that claim by eliminating the extra source of variance. Twenty-six participants voted using six prototype paper voting ballots. The ballots were randomly assigned, with three used before a fatigue manipulation and three after. All the ballots were of a similar usability profile as determined in previous studies. Each ballot was used and evaluated by the subjects using the System Usability Scale (SUS) and the pre-and post-fatigue means were compared, with no significant differences found. Although the reduction in variance did not affect the results, it was discovered that sequential usability judgments may result in decision fatigue. Subjective usability judgments may become increasingly negative with each additional judgment. Evidence from other experiments support this trend and further research may be warranted. Implications for usability researchers and practitioners are discussed.