Abstract

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.

Keywords: Interruptions; Working memory; Expertise; Human factors; Human–computer interaction; User psychology; Long-term working memory

Article Outline

1. Introduction

2. LTWM and safeguarding

2.1. Long-term working memory theory

2.2. On the nature of LTWM encoding

2.3. Objectives of the study

3. Experiments

3.1. General method

3.1.1. Participants

3.1.2. Materials

3.1.3. Procedure

3.1.4. Measurements

3.1.5. Statistical analysis

3.2. Experiment 1

3.2.1. Method

3.2.1.1. Participants

3.2.1.2. Materials

3.2.1.3. Design

3.2.1.4. Procedure

3.2.2. Results

3.2.3. Discussion

3.3. Experiment 2

3.3.1. Method

3.3.1.1. Participants

3.3.1.2. Materials

3.3.1.3. Design

3.3.1.4. Procedure

3.3.2. Results

3.3.3. Discussion

3.4. Experiment 3

3.4.1. Method

3.4.1.1. Participants

3.4.1.2. Materials

3.4.1.3. Design

3.4.1.4. Procedure

3.4.2. Results

3.4.3. Discussion

3.5. Experiment 4

3.5.1. Method

3.5.1.1. Participants, materials, design, and procedure

3.5.2. Results

3.5.3. Discussion

3.5.4. Post hoc analysis of the locus of interruption effect

3.6. Analyses of experiments 1–4

3.6.1. Power

3.6.2. Overall memory performance

4. General discussion

4.1. Role of rehearsal

4.2. Role of temporal cues

4.3. Qualities of task environments that support interruption tolerance

4.3.1. Support for development of skilful encoding

4.3.2. Match to encoding speed

4.3.3. Encoding-retrieval symmetry

Acknowledgements

Appendix A. Appendix

References