Pertti Saariluoma

Research and Innovation

Thinking is the property of the human mind. Scientists engage in constructive thinking: they set up hypotheses and test them, and develop logical chains of arguments to decide which assumptions are facts and which are not. They also create new perspectives for searching out truths by designing more accurate concepts, which allow them to ask new types of questions concerning the states of affairs.

Surviving task interruptions: Investigating the implications of long-term working memory theory

Typically, we have several tasks at hand, some of which are in interrupted state while others are being carried out. Most of the time, such interruptions are not disruptive to task performance. Based on the theory of Long-Term Working Memory (LTWM; Ericsson, K.A., Kintsch, W., 1995. Long-term working memory. Psychological Review, 102, 211-245), we posit that unless there are enough mental skills and resources to encode task representations to retrieval structures in long-term memory, the resulting memory traces will not enable reinstating the information, which can lead to memory losses. However, once encoded to LTWM, they are virtually safeguarded. Implications of the theory were tested in a series of experiments in which the reading of an expository text was interrupted by a 30-s interactive task, after which the reading was continued. The results convey the remarkably robust nature of skilled memory-when LTWM encoding speed is fast enough for the task-processing imposed by the interface, interruptions have no effect on memory, regardless of their pacing, intensity, or difficulty. In the final experiment where presentation time in the main task was notably speeded up to match the limits of encoding speed, interruptions did hamper memory. Based on the results and the theory, we argue that auditory rehearsal or time-based retrieval cues were not utilized in surviving interruptions and that they are in general weaker strategies for surviving interruptions in complex cognitive tasks. We conclude the paper by suggesting three ways to support interruption tolerance by the means of task and interface design: (1) actively facilitating the development of memory skills, (2) matching encoding speed to task processing demands, and (3) supporting encoding-retrieval symmetry.

Long-term working memory and interrupting messages in human-computer interaction

The extent to which memory for information content is reliable, trustworthy, and accurate is crucial in the information age. Being forced to divert attention to interrupting messages is common, however, and can cause memory loss. The memory effects of interrupting messages were investigated in three experiments. In Experiment 1, attending to an interrupting message decreased memory accuracy. Experiment 2, where four interrupting messages were used, replicated this result. In Experiment 3, an interrupting message was shown to be most disturbing when it was semantically very close to the main message. Drawing from a theory of long-term working memory it is argued that interrupting messages can both disrupt the active semantic elaboration of content during encoding and cause semantic interference upon retrieval. Properties of the interrupting message affect the extent and type of errors in remembering. Design implications are discussed.

Location coding in chess

Whether the chunks used in memorizing chess positions are general and relatively encoded schemata or very precisely coded instances is a problem that has raised some controversy within the psychology of chess skill. As chess research has had a strong impact on expertise research, this problem is important in many areas of skills research other than chess. To resolve it, four experiments were set up. In the experiments it was shown that subjects were better at recalling correctly located non-transposed chunks than transposed chunks, which were similar in structure but incorrectly located on the chessboard. The results imply that the representation of chess-specific patterns in the memory of a chess player contains not only information about the forms of chess-specific patterns, but also about their absolute locations on the chessboard. This provides an explanation for the well-known interaction between skill and type of position and its disappearance in recent experiments by Lories and Saariluoma. It can be argued that the difficulty of recalling random positions is not chiefly caused by the total absence of chunks but by their dislocation.

Emotional Dimensions of User Experience: A User Psychological Analysis

User psychology is a human–technology interaction research approach that uses psychological concepts, theories, and findings to structure problems of human–technology interaction. As the notion of user experience has become central in human–technology interaction research and in product development, it is necessary to investigate the user psychology of user experience. This analysis of emotional human–technology interaction is based on the psychological theory of basic emotions. Three studies, two laboratory experiments, and one field study are used to investigate the basic emotions and the emotional mind involved in user experience. The first and second experiments study the measurement of subjective emotional experiences during novel human–technology interaction scenarios in a laboratory setting. The third study explores these aspects in a real-world environment. As a result of these experiments, a bipolar competence–frustration model is proposed, which can be used to understand the emotional aspects of user experience.

Taxi drivers’ exceptional memory of street names

In this paper, we explore the nature of taxi drivers’ serial recall of street names. The main question is whether the memory of verbal material benefits from the possibility of using visuospatial associations and knowledge concerning large-scale environment. In two experiments, expert taxi drivers’ recall of street names was superior to that of control groups. In Experiment 1, experts’ superiority of memory was greater when the street names reflected a visuospatially continuous route than when the street names were located along a straight line across the map without spatial continuity or were presented in random order. In Experiment 2, the expert taxi drivers recalled spatially continuously organized lists much better than they recalled lists of street names belonging to the same semantic category or lists presented in alphabetical order. This result also suggests that interitem associations, which are based on spatial co-occurrence, are efficient in comparison with other mnemonics.

Visual information chunking in spreadsheet calculation

Abstract Spreadsheet calculation causes a heavy memory load, since it is necessary to remember complex cell and calculation systems. A series of experiments were carried out to study the role of visual information chunking in spreadsheet calculation. The experiments showed that a possibility to visual information chunking substantially decreases the memory load caused by spreadsheet calculation. If subjects are able to induce the structure of a formula or a network of connected formulas, they usually learn it fast. The surface structure of a formula may cause subjects essential difficulties in chunking. Badly ordered formula networks, in which cell layers are embedded within each other and references cross each other, are difficult to learn and remember. Subjects are not able to abstract the deep structure and encode formula networks.

Defining user experience goals to guide the design of industrial systems

The key prerequisite for experience-driven design is to define what experience to design for. User experience (UX) goals concretise the intended experience. Based on our own case studies from industrial environments and a literature study, we propose five different approaches to acquiring insight and inspiration for UX goal setting: Brand, Theory, Empathy, Technology, and Vision. Each approach brings in a different viewpoint, thus supporting the multidisciplinary character of UX. The Brand approach ensures that the UX goals are in line with the companys brand promise. The Theory approach utilises the available scientific knowledge of human behaviour. The Empathy approach focuses on knowing the actual users and stepping into their shoes. The Technology approach considers the new technologies that are being introduced and their positive or negative influence on UX. Finally, the Vision approach focuses on renewal, introducing new kinds of UXs. In the design of industrial systems, several stakeholders are involved and they should share common design goals. Using the different UX goal-setting approaches together brings in the viewpoints of different stakeholders, thus committing them to UX goal setting and emphasising UX as a strategic design decision.

Apperception, content-based psychology and design

A core area of scientific thinking is explaining. This means answering to the “why-questions and how questions” (Hempel 1965). Why does Sam have a fewer? Why did an organization fail abroad? Why a structure is able to support the weight of snow? How more effective valves for an engine can be designed? How to make computer games more attractive for female users? These are typical examples of design problems, all of which should be based on scientific explanation, i.e., what should be answered based on the laws of nature or as is becoming increasingly more evident, based on the laws of the human mind.

Transforming verbal descriptions into mathematical formulas in spreadsheet calculation

A common subtask in spreadsheet calculation is the transformation of verbal task instructions into spreadsheet formulas. This task can be used to study the relation of imagery to thinking. Research using physics and mathematics problems has indicated that mental transformation from verbal to mathematical representations is not necessarily direct but is intermediated by imagery. Therefore, a human-computer interaction task such as spreadsheet calculation provides a good task environment for analysing mental imagery operations, the role of imagery operations, and the role of intermediate imagery in thinking tasks. Testing the use of imagery in spreadsheet calculations also improves our understanding of representational systems used in this specific task and in user interfaces in general.Four experiments provided different types of evidence for the intermediate imagery hypothesis, which means that subjects do not directly transform verbal instructions into spreadsheet formulas. They first try to code an overall image of the areas referred to by verbal instructions, segment it into suitable fields, and only thereafter do they write down the set of formulas which best extract the information demanded. Typically, the field borders, used in this segmentation are often imagined and are not presented at all in the original verbal task instructions.Intermediate imagery is a relevant notion in discussing the construction of user models because the most important current models, such as GOMS, assume only propositional representations. Also, the use of images should be taken into account in designing spreadsheet packages by providing features which aid analog information processing.