TAM posits that the intention to adopt a particular technology is driven by two kinds of perceptions: (1) how easy it is to use a system and (2) how useful it will be to use it [180]. Furthermore, the perceived ease of use affects the perceived usefulness: If technology is hard to use, it is less useful.

it is perfectly possible to have a program which is structured, modular, readable, flexible, self-documenting, maintainable, which performs its specified function, and which is a source of constant frustration and irritation to its users.

The theory of task–technology fit (TTF) can illuminate what users consider useful and how this affects their decision to adopt a particular technology. TTF refers to the ability of technology to support a task [197]. The capabilities of the technology should match the demands of the task and the skills of the individual; in this case, the fit is perfect.

Users actively repurpose tools to make them more personally usable and relevant. Design should support such repurposing. For example, Renom et al. [696] conducted a study on text editing using a novel user interface. They found that exploration and technical reasoning facilitate creative tool use.

One prominent definition of accessibility is given by ISO 9241-171, which defines it as 'the usability of a product, service, environment or facility by people with the widest range of capabilities.'

The second dimension, social acceptability, concerns whether interactions map well to the social norms and roles in the settings where they occur.

Acceptability has two main dimensions [591]. The first dimension, practical acceptability, includes costs, the reliability of the interactive system, and its compatibility with other systems. The perceptions of utility and usability may also influence the judgment of practical acceptability.

usability is multidimensional. This means that in most settings, a valid characterization of usability will need to employ several dimensions and measures.

usability is measurable, that is, it is possible to quantify usability based on users' behaviors or opinions.

usability is relational; it arises as an interplay between people, tasks (problems), and interactive systems (tools)

ISO 9241-11 definition... defines usability as the 'extent to which a system, product or service can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use.'

One shorthand way of expressing this is that utility is 'whether the functionality of a system in principle can do what is needed' [591, p. 25]. In practice, whether people can do anything concerns—among other things—usability.

The utility of an interactive system concerns its match with the tasks of users. If the match is good, the tool has high utility; if the tasks that users want to do are not supported by the tool, the tool has low utility.

Usability concerns how easily computer-based tools may be operated by users trying to accomplish a task. Usability differs from utility. Usability concerns whether users can use the product in a way that makes it possible to realize its utility; utility is about whether the goal is important to the user. Ideally, the user can use the tool without unnecessary effort so that the use is direct, transparent, and unnoticeable.

Usability is one of the best predictors of users' willingness to adopt software. For example, the User Burden Scale is a questionnaire for measuring the felt burden in software use [806]. It consists of six subscales: difficulty of use, physical burden, time and social burden, mental and emotional burden, privacy burden, and financial burden.

Trailblazer offers you a new, more intuitive file layout in applications.

Instead of grouping by technology, classes and views are structured by concept, and then by technology. A concept can relate to a model, or can be a completely abstract concern such as invoicing.

While Trailblazer offers you abstraction layers for all aspects of Ruby On Rails, it does not missionize you. Wherever you want, you may fall back to the "Rails Way" with fat models, monolithic controllers, global helpers, etc. This is not a bad thing, but allows you to step-wise introduce Trailblazer's encapsulation in your app without having to rewrite it.