ITA 2.0: A Program for Classical and Inductive Item Tree Analysis

Item Tree Analysis (ITA) is an explorative method of data analysis which can be used to establish a hierarchical structure on a set of dichotomous items from a questionnaire or test. There are currently two different algorithms available to perform an ITA. We describe a computer program called ITA 2.0 which implements both of these algorithms. In addition we show with a concrete data set how the program can be used for the analysis of questionnaire data.

ITA 2.0: A Program for Classical and Inductive Item Tree Analysis

Item Tree Analysis (ITA) is an explorative method of data analysis which can be used to establish a hierarchical structure on a set of dichotomous items from a questionnaire or test. There are currently two different algorithms available to perform an ITA. We describe a computer program called ITA 2.0 which implements both of these algorithms. In addition we show with a concrete data set how the program can be used for the analysis of questionnaire data

Design and Validation of a Framework for the Creation of User Experience Questionnaires

Existing user experience questionnaires have a fixed number of scales. Each of these scales measures a distinct aspect of user experience. These questionnaires can be used with little effort and provide a number of useful support materials that make the application of such a questionnaire quite easy. However, in practical evaluation scenarios it can happen that none of the existing questionnaires contains all scales necessary to answer the research question. It is of course possible to combine several UX questionnaires in such cases, but due to the variations of item formats this is also not an optimal solution. In this paper, we describe the development and first validation studies of a modular framework that allows the creation of user experience questionnaires that fit perfectly to a given research question. The framework contains several scales that measure different UX aspects. These scales can be combined to cover the relevant research questions

Techniques for Sampling Quasi-orders

In educational theories, e.g., learning spaces, mastery dependencies between test items are represented as reflexive and transitive binary relations, i.e., quasi-orders, on the item set of a knowledge domain. Item dependencies can be used for efficient adaptive knowledge assessment and derived through exploratory data analysis, for example by algorithms of item tree analysis. To compare item tree analysis methods, typically large-scale simulation studies are employed, with samples of randomly generated quasi-orders at their basis and assumed to underlie the data. In this context, a serious problem is the fact that all of the algorithms are sensitive to the underlying quasi-order structure. Thus, it is crucial to base any simulation study that aims at comparing the algorithms in a reliable manner on representative samples, meaning that each quasi-order in the population is equally likely to be selected as part of a sample. Suboptimal sampling strategies were considered in previous studies leading to biased conclusions. In this paper, we discuss sampling techniques that allow us to generate representative, or close to representative, random quasi-orders. The item tree analysis methods are compared on ten items with a representative, large sample of quasi-orders, thereby supporting their invariant ordering

Construction of a Benchmark for the User Experience Questionnaire (UEQ)

Questionnaires are a cheap and highly efficient tool for achieving a quantitative measure of a product’s user experience (UX). However, it is not always easy to decide, if a questionnaire result can really show whether a product satisfies this quality aspect. So a benchmark is useful. It allows comparing the results of one product to a large set of other products. In this paper we describe a benchmark for the User Experience Questionnaire (UEQ), a widely used evaluation tool for interactive products. We also describe how the benchmark can be applied to the quality assurance process for concrete projects

Design and Evaluation of a Short Version of the User Experience Questionnaire (UEQ-S)

The user experience questionnaire (UEQ) is a widely used questionnaire to measure the subjective impression of users towards the user experience of products. The UEQ is a semantic differential with 26 items. Filling out the UEQ takes approximately 3-5 minutes, i.e. the UEQ is already reasonably efficient concerning the time required to answer all items. However, there exist several valid application scenarios, where filling out the entire UEQ appears impractical. This paper deals with the creation of an 8 item short version of the UEQ, which is optimized for these specific application scenarios. First validations of this short version are also described

Do Women and Men Perceive User Experience Differently?

We study three web sites to see whether there are systematic differences between women and men in their rating of the user experience of the sites. One of the sites addresses especially the target group of women, another the target group of men, whereas the third site is neutral in this respect. The selection of the sites was safeguarded with gender screening. The participants in the study rated the three chosen websites with the questionnaires UEQ and VISAWI-S. The results indicate that there are no substantial differences in the perception of the UX between men and women. Personal attitudes and preferences seem to have a substantially greater influence than sex

VRpursuits: Interaction in Virtual Reality Using Smooth Pursuit Eye Movements

Gaze-based interaction using smooth pursuit eye movements (Pursuits) is attractive given that it is intuitive and overcomes the Midas touch problem. At the same time, eye tracking is becoming increasingly popular for VR applications. While Pursuits was shown to be effective in several interaction contexts, it was never explored in-depth for VR before. In a user study (N=26), we investigated how parameters that are specific to VR settings influence the performance of Pursuits. For example, we found that Pursuits is robust against different sizes of virtual 3D targets. However performance improves when the trajectory size (e.g., radius) is larger, particularly if the user is walking while interacting. While walking, selecting moving targets via Pursuits is generally feasible albeit less accurate than when stationary. Finally, we discuss the implications of these findings and the potential of smooth pursuits for interaction in VR by demonstrating two sample use cases: 1) gaze-based authentication in VR, and 2) a space meteors shooting game

What Causes the Dependency between Perceived Aesthetics and Perceived Usability?

Several studies reported a dependency between perceived beauty and perceived usability of a user interface. But it is still not fully clear which psychological mechanism is responsible for this dependency. We suggest a new explanation based on the concept of visual clarity. This concept describes the perception of order, alignment and visual complexity. A high visual clarity supports a fast orientation on an interface and creates an impression of simplicity. Thus, visual clarity will impact usability dimensions, like efficiency and learnability. Visual clarity is also related to classical aesthetics and the fluency effect, thus an impact on the perception of aesthetics is plausible. We present two large studies that show a strong mediator effect of visual clarity on the dependency between perceived aesthetics and perceived usability. These results support the proposed explanation. In addition, we show how visual clarity of a user interface can be evaluated by a new scale embedded in the UEQ+ framework. Construction and first evaluation results of this new scale are described

Applicability of User Experience and Usability Questionnaires

To be successful, interactive products need to fulfil user expectations and create a positive user experience (UX). An established method to measure UX involves questionnaires. What we aim in this paper is to present a list of user experience and usability questionnaires and its applicability for different digital products. A total of 13 questionnaires on usability and UX were analysed for this paper, and 25 factors were extracted from those questionnaires. A study was conducted based on this collection of factors with N=61 students. The study investigated the perceived importance of usability and UX factors for seven digital products. The goal was to have a collection of usability and UX factors that could be combined for suitable products evaluation. The results of the study revealed that no questionnaire covered all the factors perceived important by the participants