The Software Usability Measurement Inventory: Background and Usage 3

You can change it to awkward or to cumbersome/awkward without any impact on results. If you want to rate “usability” separately from “learnability,” you can pull out items 4 and 10 and score these separately. However, you can’t tweak it too much or it stops being the SUS.

The Software Usability Measurement Inventory is the latest development in a series of studies into questionnaire methods of analyzing user reactions which started in 1986. An earlier landmark was the Computer User Satisfaction Inventory (see Kirakowski, 1987; Kirakowski and Corbett, 1988). Both CUSI and SUMI depend on there being a working version of the software system. A group of typical users is needed, who have experience of doing a set of representative tasks with the system in a known and specifiable environment. The users then rate the system using the questionnaire and the results are analyzed in a standardized manner, to yield quantitative, numerical data. The result is the users’ view of the quality of use of the system being evaluated.

definition of software usability measurement inventory

The SUS has been in use for quite some time, having been developed in 1986. The 10-item questionnaire is short, and free, as long as you acknowledge the source. A SUS score is best presented as a single number—ranging from 0 to 100—representing a composite measure of the overall usability of the system being studied. SUMI is “a mature questionnaire whose standardization base and manual have been regularly updated.” It is applicable to a range of application types from desk-top applications to large domain-complex applications. SUMI is “a mature questionnaire whose standardization base and manual have been regularly updated.” It is applicable to a range of application types from desktop applications to large domain-complex applications.

In this paper, Software Usability Measurement Inventory is used to evaluate a tool for cost estimate called WebCost, which shows WebCost provides easier interfaces and produces accurate cost estimation results. The SUMISCO report generator is the interface to the extensive standardisation data base developed for SUMI and which is regularly up-dated and maintained. Although there were other options available to conduct a post-test questionnaire (the Questionnaire for User Interaction Satisfaction , the Software Usabil- ity Measurement Inventory or the Post-Study System Usability Questionnaire ), SUS has become one of the most popular post-study standardized questionnaires . The software development process, especially when it comes to complex projects, suggests multiple layers of such factors as customer demands, devel… Methods for testing the practicality of the use of the software product from the point of view of the end user based on the survey.

You can use fewer repondents if you wish, but beware that your results may not be as representative of the true user population. In fact, SUMI has yielded useful information with sample sizes of four or five. The ISO standard includes references to some well-known satisfaction questionnaires such as QUIS developed by Chin, Diehl, and Norman and the SUMI questionnaire developed by J.


As you can see, the statements use the word system, which reflects its original use for software evaluation. It is common practice to substitute website, product, or interface for system without affecting the results. In their comparative evaluation of two websites using five questionnaires to determine user preference, they found that SUS and CSUQ produced the most consistent results with varying sample sizes. The Questionnaire For User Interaction Satisfaction is a tool developed to assess users’ subjective satisfaction with specific aspects of the human-computer interface. This paper has analyzed ten famous quality models for developing a usability model which satisfy the demand of current business software and proposed an integrated improved usability model for assuring software quality. The research reported here examines the usability of Computer Assisted Assessment and the development of domain specific heuristics and concludes with a discussion of the heuristic design methodology and potential for future work.

definition of software usability measurement inventory

It is relatively easy to move from one part of a task to another. It is easy to forget how to do things with this software. This software occasionally behaves in a way which can’t be understood. It is easy to see at a glance what the options are at each stage. Getting data files in and out of the system is not easy.

Although evidence of gender differences would not affect the usefulness of the PSSUQ, it’s notable that the instrument does not appear to have an inherent gender bias. In the office applications study described by Lewis et al. Let’s say you have some rough competitors in the market.

The difference between the complete and incomplete questionnaire means for each of the PSSUQ scales was only 0.1, and the changes cancelled out for the Overall score (means of 2.7 for both complete and incomplete questionnaires). This finding is important because it supports the practice of including rather than discarding partially completed PSSUQ questionnaires when averaging items to compute scale scores. The data do not provide information concerning how many items a participant might ignore and still produce reliable scores, but they do suggest that, in practice, participants typically complete enough items.

Are questionnaires designed for the assessment of perceived usability, typically with a specific set of questions presented in a specified order using a specified format with specific rules for producing scores based on the answers of respondents. For usability testing, standardized questionnaires are available for assessment of a product at the end of a study (post-study—e.g., QUIS, SUMI, PSSUQ, and SUS) and after each task in a study (post-task—e.g., ASQ, Expectation Ratings, SEQ, SMEQ, and Usability Magnitude Estimation). Standardized questionnaires are also available for the assessment of website usability (e.g., WAMMI and SUPR-Q) and for a variety of related constructs.

Usability engineering

Developed by John Brooke at Digital Equipment Corporation, uses 10 Likert-type statements with responses based on a 5-point scale. 14.The information was effective in helping me complete the tasks and scenarios. 3.I could effectively complete the tasks and scenarios using this system. For gender, neither the main effect nor the interaction was significant. The difference between the female and male questionnaire means for each of the PSSUQ scales was only 0.1.

definition of software usability measurement inventory

In order to be widely useful, the SUS is necessarily general. If you want to get more specific about aspects of your product, you can add questions at the end. Just be aware that you shouldn’t include these in the SUS score. The even-numbered items are positive statements, and the odd-numbered items are negative statements.

Considerations when using a SUS

Based on human information processing theory, eight human factors considerations which are relevant to software usability are identified which formed the framework from which the Purdue Usability Testing Questionnaire is derived. Take a look at the detailed article about how SUMI was constructed. If you put “SUMI questionnaire” into any decent search engine you’ll find many pages about how SUMI has been promoted by many orgainsations, and used in applications and research. Use for the third step in the process of estimating n for a McNemar exact test . The System Usability Scale questionnaire shows a sample response and the total score.

  • The data do not provide information concerning how many items a participant might ignore and still produce reliable scores, but they do suggest that, in practice, participants typically complete enough items.
  • Each language version has been carefully translated, back translated, and validated by teams of native speakers of the target language.
  • This paper summarizes results of SUMI questionnaires analysis of product PS designed using TEIM model, which identified usability issues of PS.
  • For convenience, you can use the search bar to simplify and speed up the search process.
  • The 10-item questionnaire is short, and free, as long as you acknowledge the source.

The everyday work of the software development specialists coupled with specialized vocabulary usage. It may be challenging for customers to understand it. Situations of misunderstanding between clients and team members could lead to an increase in overall project time. To avoid such unfavorable scenarios, we prepare the knowledge base. In the glossary we gather the main specialized terms that are frequently used in the working process. All meanings are written according to their generally accepted international interpretation.

SUPR-Q — Standardized User Experience Percentile Rank Questionnaire

Explore the possibility to hire a dedicated R&D team that helps your company to scale product development. Methods of testing the practicality of using the software (e.g., user satisfaction with system or component), based on the questioning technique. •To obtain a sample size estimation formula, take the formula for the appropriate test and solve for n. •To obtain a sample size estimation formula, take the formula for the appropriate test and solve forn.

For convenience, you can use the search bar to simplify and speed up the search process. The System Usability Scale provides a “quick and dirty”, reliable tool for measuring the usability. It consists of a 10 item questionnaire with five response options for respondents; from Strongly agree to Strongly disagree. Originally created by John Brooke in 1986, it allows you to evaluate a wide variety of products and services, including hardware, software, mobile devices, websites and applications.

•Different research goals (e.g., estimation of a value, comparison with a benchmark, or comparison among alternatives) require different methods for sample size estimation. In addition, some tweaking of the language of the questions is acceptable. For example, one study showed that non-native speakers in particular have difficulty with the word cumbersome in item 8.

The software has helped me overcome any problems I have had in using it. DisagreeI sometimes wonder if I am using the right function. The way that system information is presented is clear and understandable. This software seems to disrupt the way I normally like to arrange my work. There is never enough information on the screen when it’s needed.

definition of software usability measurement inventory

To easily show someone how good your product is, a number is probably the most effective way. Then there comes a lot of metrics you can tell, for example the completion time, errors, … that may reflect some aspects of a product. For an overall score of how your product is, well, you may find it useful to try Standardized Usability Tests. This chapter discusses object-oriented software engineering as a process of change, management and reuse, and some of the methods used to develop and implement object- oriented software. This guide uses the term ‘context’ to include all factors which affect the usability of the product, excluding the features of the Product, to represent any interactive system or device designed to support the performance of users’ tasks.

An analysis over the most commonly used standardised questionnaires is presented based on a comparison between them and the results of an analysis done by a group of students, who were asked to compare and decide which standardised questionnaire would be appropriate for their usability evaluation over a certain project. This paper presents the result of a detailed analysis of all items being evaluated in each questionnaire to indicate those that can identify users’ perceptions about specific usability problems and confronts each questionnaire item with usability criteria proposed by quality standards and classical quality ergonomic criteria. Database showed that of 210 total questionnaires, 124 (59%) were complete and 86 (41%) were incomplete.

Besides overall score, you can break down the score into smaller parts, or even each item to compare which item has the highest score and which has the lowest. It’s easy then to find out where the real problem is and clearly set the next goal to upgrade it. Imagine you want to redesign a page/product, you make an SUS survey to test the usability before redesigning. DisagreeThe software hasn’t always done what I was expecting. The software presents itself in a very attractive way. Either the amount or quality of the help information varies across the system.

The reason for the calculation is the test is based on a 100 score scale, and there are 10 questions, so each should account for 10, maximum is 10 and minimum is 0. SUPR-Q or Standardized User Experience Percentile Rank Questionnaire helps measure the Usability, Credibility/Trust, Loyalty and Appearance of a website or an application (SUPR-Qm). It consists of 8 questions, 7 of them are to be answered by a 5-level scale while the 8th one is about NPS , which relates to the likeliness of a user to refer the app to a friend. The approach to the problem is presented, an instrument for calculating objective learnability out of times of completion is introduced, and results of a user study conducted to test adequacy of the method are revealed. Online SUMI might require sample sizes with a minimum of about 20 unless your respondents are well selected.

This is sent to the client as a zipped, encoded file when the evaluation has been completed. SUMI consists of 50 statements to which the user has to reply that they either Agree, Don’t Know, or Disagree. SUMI enables measurement of some of the user-orientated requirements expressed in the European Directive on Minimum Health and Safety Requirements for Work with Display Screen Equipment (90/270/EEC).