Temporal Aspects of User Experience

There are two different categories of studies pertaining to temporal aspects of user experience. The first category explores the timing of the generation and assessment of user experience (before, during, and after interactions), and the timeframe (past, present, and future) that the analysis of user experience should cover (e.g. Bargas-Avila and Hornbæk, 2011; Law, et al., 2009; Roto, et al., 2011; Vermeeren, et al., 2010). The second category of studies investigates how user experience changes and develops over time, particularly in prolonged product use (e.g. Karapanos, et al., 2009; Kujala, et al., 2011; von Wilamowitz-Moellendorff, et al., 2006).

In relation to the first category of studies, Roto et al. (2011) conceptualise a series of time spans of user experience:

1. Anticipated user experience – imagining experience before usage. This relates to indirect experience through expectations created from previous experiences and other sources of information.

2. Momentary user experience – experiencing during usage. This relates to specific emotions and feelings elicited during interaction.

3. Episodic user experience – reflecting on an experience after usage. This relates to the assessment of a specific usage episode.

4. Cumulative user experience – recollecting multiple periods of use over time. This relates to global perceptions of the product after many periods of use and non-use.

Roto et al. (2011) stress that focusing on different time spans of user experience results in different information about the experience, thus placing different demands on design and evaluation. In a similar vein, Vermeeren et al. (2010) classify user experience evaluation methods based on the attribute period of experience, which comprises five variables: before usage, momentary, single episode, short-term usage, and long-term usage. Thus, it can be suggested that the understanding of each time span or period of experience allows more accurate assessment of user experience, and helps with the setting and achievement of specific design targets.

The nature of user experience – which is dynamic, context-dependent, and subjective (Hassenzahl and Tractinsky, 2006; Law, et al., 2009) – underlies the second category of studies of temporal aspects of user experience. As user experience is a continuing process, a single use situation is inadequate to represent the whole experience (Kujala, Minge, Pohlmeyer, and Vogel, 2012). Moreover, it is the long-term experience that determines user loyalty and ongoing use of a product (Kujala, et al., 2011). Designing for such experience requires designers to understand and measure how users’ experience and their relationship with a product change over time (Karapanos, et al., 2010; Kujala, et al., 2011). For this reason, Vermeeren and Kort (as cited in Pals, et al., 2008) suggest that user experience evaluation tools should enable in situ measurements and measurements in different contexts, as well as support longitudinal studies and continuous or timed measurements.

A number of studies have demonstrated that users’ perception of a product’s quality dimensions changes over time (e.g. von Wilamowitz-Moellendorff, et al., 2006).

Several others have also shown how the relative importance of those quality dimensions shifts throughout different phases of product use (e.g. Karapanos, et al., 2008; Karapanos, et al., 2009). For example, von Wilamowitz-Moellendorff et al.

(2006) investigate the dynamics of quality perceptions of mobile phones by using a retrospective interview technique that reconstructs changes in user experience over more than a year period. The changes in the perceived qualities over time were measured by addressing two pragmatic (i.e. utility and usability) and three hedonic (i.e. stimulation, beauty, and identification) quality dimensions. The authors discovered that pragmatic perceptions continued to be steady (utility) or improved (usability) over time. In contrast, all hedonic perceptions (especially stimulation) declined. Utility and stimulation, which focus on the self, were both influenced by increasing familiarity with the product; on the other hand, beauty and identification, which are related to social aspects, were affected by comparisons with other people’s products (von Wilamowitz-Moellendorff, et al., 2006).

Karapanos et al.’s (2008) study reveals that during early experiences with a product, the product’s perceived goodness was primarily determined by pragmatic dimensions (utility and usability). After four weeks of use, however, the goodness of the product was prominently formed on the basis of a hedonic dimension (identification).

Furthermore, while stimulation largely shaped judgments of the product’s beauty in the first week of use, over time its influence on the product’s perceived beauty deteriorated (Karapanos, et al., 2008). Accordingly, it is argued that in long-term experience, aspects of product ownerships, rather than of product use, play a more significant role in integrating the product into the user’s everyday life (Karapanos, et al., 2008). Nonetheless, as also acknowledged by the authors, this study only measured the users’ perceptions at two discrete points in time (the first and the fourth week), rather than measuring them repeatedly over a continuous period. Hence, the dynamics of user experience presented may be limited.

In response to the above limitation and to explore how the quality of user experience develops over time, Karapanos et al. (2009) conducted a longitudinal study over a five-week period, monitoring six participants during the purchase and usage of the Apple iPhone. They found that the product qualities that evoked positive early experiences would be replaced by different qualities to motivate ongoing use of the product. Hedonic aspects (e.g. novelty) that mainly shaped the first experiences of use faded away quickly, and the product’s ability to be meaningful in users’ lives increasingly became the main factor that formed long-term experiences (Karapanos, et al., 2009).

The authors go a step further by proposing a conceptual model of user experience temporality as comprising three sequential forces: increasing familiarity, functional dependency, and emotional attachment. These forces contribute to the shift of users’

experience across three distinct stages of the product adoption process: orientation, incorporation, and identification (Karapanos, et al., 2009). In each stage, different quality dimensions are valued: (1) the early orientation to the product is largely influenced by stimulation and learnability qualities; (2) the incorporation of the product in users’ daily lives is characterised by long-term usability and usefulness;

and (3) the identification with the product is dominated by the product’s abilities to partake in users’ personal and social experiences (Karapanos, et al., 2009).

Lightweight alternatives to laborious and time consuming longitudinal studies of user experience temporality have been recently proposed. They include the use of iScale (Karapanos, et al., 2010) and UX Curve (Kujala, et al., 2011) methods. The iScale employs sketching, and aims to retrospectively elicit users’ most impactful

experiences in the form of experience narratives. Karapanos et al. (2010) used this method to study the changes of users’ experiences with mobile phones over the first six months of use. The results mostly confirm their previous finding (in Karapanos, et al., 2009) regarding the changes of four perceived qualities – innovativeness, learnability, long-term usability, and usefulness – over time. They also show that the majority of users’ experiences (75%) were related to the first month of product use.

Similar to iScale, UX Curve is a retrospective technique that asks users to draw a curve delineating how their experiences with a product have evolved from the first time of use until the present (Kujala, et al., 2011). Focusing on attractiveness, ease of use, utility, and degree of usage aspects, K ujala et al. (2011) employed the UX Curve to investigate the quality of prolonged experiences with mobile phones and the factors that improve or deteriorate the experiences over time. They found that the attractiveness curves produced the highest number of reasons explaining the changes of user experience, and that these reasons seemed to focus on hedonic aspects (e.g.

beauty, stimulation, and pleasure). Furthermore, K ujala et al. (2011) suggest that the improving perceived attractiveness of a product over time pertained to users’

satisfaction and willingness to recommend the product to others.

2.6 SUMMARY

User experience is becoming more widely accepted as an indicator of the quality of user-product interaction. It is also increasingly becoming a design goal. However, the definition, theory, and scope of user experience are still evolving, and a unified understanding has not yet been reached (Law, et al., 2009). This fact is reflected in the diverse range of definitions, models, and frameworks presented in this chapter.

There is, however, general agreement that user experience is subjective, context-dependent, and dynamic (Hassenzahl and Tractinsky, 2006; Law, et al., 2009).

Another key attribute that characterises user experience and differentiates it from usability is its holistic attribute. That is, user experience includes not only instrumental aspects (e.g. functionality and ease of use), but also includes non-instrumental aspects (e.g. aesthetics, emotion, and self-expression). Hassenzahl (2003, 2008) refers to instrumental aspect as pragmatic quality, and to non-instrumental aspect as hedonic quality (Section 2.3). He argues that hedonic quality

contributes directly to positive user experience, whereas pragmatic quality only acts as a ‘barrier remover’.

This chapter presented a picture of known definitions, models, and frameworks of user experience (Section 2.2 and Section 2.4), all of which appear to generally regard user experience as a result of using products or systems. In other words, user experience is viewed as being constructed during or after actual interactions between users and products or systems. For example, models from Hassenzahl (2003) and Mahlke and Thüring (2007) both assume that the perception of a product’s qualities is the outcome of repeated interactions between users and the product’s features (Section 2.4.2). Hence, the notion of user experience before interaction or anticipated experience is still widely disregarded. While acknowledging that there are some exceptions to this disregard (e.g. ISO 9241-210, 2010; Roto, 2007; Sward and Macarthur, 2007), it is concluded that existing definitions, models, and frameworks of user experience do not, for the most part, support the early stages of product development, during which interactions with an actual product (prototype) are not possible. This is the identified knowledge gap that is addressed in this study.

This research explores both anticipated (before interaction) and real (during and after interaction) user experiences. Therefore, the temporal aspects of user experience become relevant. Roto et al. (2011) distinguish four sequential time spans:

anticipated, momentary, episodic, and cumulative user experience (Section 2.5). In relation to this research, anticipated experience belongs to the first time span, while real experience belongs to the three other spans. A focus on different time spans produces different information about the experience, thus placing different demands on design and evaluation (Roto, et al., 2011). The dynamics of user experience also cause the relative importance of quality dimensions to change over time; for example, improving or deteriorating (e.g. Karapanos, et al., 2009; von Wilamowitz-Moellendorff, et al., 2006).

The next chapter reviews and discusses various methods and approaches for evaluating user experience. The evaluation methods that can support the early stages of product development are highlighted.