Large railway projects suffer from major cost overruns and delays, partly due to project complexity. This study explores how such complexity emerges in the early design stages and affects the project outcomes. Data from 14 interviews were compared with four project complexity frameworks. The results indicate that complexity is mainly institutional rather than structural. Optimism bias, fragmented requirement governance, and weak coordination create self-reinforcing loops of cost growth, showing that governance and decision processes, not technical uncertainty, drive early-stage complexity.

This paper provides a structured overview of methods for assessing assembly complexity in manufacturing. A systematic literature review classifies approaches as product-, information-, or system-centered, each reflecting distinct sources of complexity and application contexts. A four-dimensional scheme enables consistent comparison. The results highlight methodological gaps and support future development of scalable, integrable models for planning and decision-making in high-variety production environments.

Large infrastructure projects often face misalignments that Delays outcomes. This paper presents a co-design workshop addressing such challenges in a European railway project. Guided by complexity theory, the workshop enabled participants to reflect and co-create strategies for alignment. Pre/post surveys and facilitator observations show increased confidence and engagement, with notable awareness in addressing misalignments. These findings highlight co-design’s value as an adaptive, participatory approach for creating recognition and managing complexity in interorganizational projects.

Product variety increases complexity across product, process, and organizational domains, yet existing complexity measures offer limited guidance for design decisions. This study implements established metrics within a framework to enable consistent assessment across domains. The results reveal substantial redundancies among these metrics - with the notable exception of modularity, emphasizing its central role in complexity management. The consolidated measure set provides practitioners with a systematic basis for evaluating design strategies and managing complexity in product families.

This article examines the hybrid network structure of the global sustainability governance system, focusing on the evolving relationships between private transnational regulators (PTRs) and intergovernmental organizations (IOs). We argue that a defining feature of this structure is the mutual dependence between PTRs and IOs: PTRs invoke public international law instruments (PILIs) – and, by extension, the authority of the IOs behind them – to bolster their own authority and to enhance the normative force of the standards they promulgate. IOs rely on PTRs to disseminate their norms within corporate settings, thereby strengthening their compliance capacities. This interdependence carries significant synergistic potential. We examine the grounding relationship between PTRs and PILIs/IOs through extensive network analysis based on a specially curated dataset comprising 55 PTRs, 393 private standards, 261 PILIs (including treaties, conventions, and declarations), and 41 IOs. Citation patterns within this network support our thesis. We also offer tentative evidence regarding the second prong of our model and outline directions for future research. Finally, we assess the vulnerabilities of this interdependent structure, highlighting the fragility of the global sustainability legal order in the face of rising nationalism and anti-multilateralist pressures.

The effect of sound change and analogy upon inflectional paradigms has been traditionally described through Sturtevant’s Paradox, which states that sound change is regular but generates irregularity, whereas analogy is irregular but generates regularity. While past work has explored trends in sound change and analogy qualitatively, quantitative investigation with large data sets remains underexploited. We tackle this by exploring the effects of sound change and analogy from Latin to French in large etymologically paired inflected lexicons containing the complete paradigms of 310 verbs with 11,593 total forms. We employ a novel method combining the automated application of historical sound changes and entropy-based quantitative analysis to examine separately the effects of sound change and analogy. The results confirm the role of some oft-cited predictors of analogy like token frequency and morphological regularity, but offer no support for others like markedness. Results also confirm the complexifying role of sound change, and the simplifying role of analogy, on aspects of morphological complexity like the number of inflection classes and the amount of allomorphy, but suggest that these forces have no comparable effect on more modern measures of complexity like average conditional entropies between inflected forms.

We introduce a new framework for understanding how cognitive systems (e.g., humans) learn from experience, based on the concept of representational capacity—the relative amount of representational resources devoted to encoding past experiences. Most paradigms in cognitive science have operated under the assumption that these resources are constrained, forcing cognitive systems to compress rich and noisy experiences to effectively generalize to new situations. We leverage recent advances in computer science to outline the implications of learning with excess capacity, or applying even more representational resources than needed to perfectly memorize all the details of one’s past experiences. In particular, we review evidence suggesting that excess capacity systems can exhibit many of the characteristics of human learning, such as the simultaneous ability to memorize individual experiences and generalize knowledge to new situations. We define and differentiate between constrained (not enough), sufficient (just enough), and excess (more than enough to perfectly capture all the details of one’s past experiences) capacity. We derive empirical properties of learning in each of these capacity regimes, and compare these predictions to effects documented for human learning. We highlight the broad implications of this framework for advancing theoretical and empirical work across cognitive, clinical, and developmental psychology.

This study examines the interaction between regularity and complexity in the acquisition of morphology and morpho-syntax in Hebrew nominal inflection. Seventy-eight Hebrew-speaking children, ages 4–8, were tested, using sentence completion tasks, on nine structures from three linguistic systems: singular adjectival agreement, noun pluralization, and plural adjectival agreement. Regularity and complexity emerged as organizing factors across ages: regular structures precede irregular ones, and within each level of regularity, less complex structures were acquired before more complex ones. The findings are discussed within the Dual-Route Model pointing to the difference between rule-governed and memory-based knowledge, while suggesting that the advantage of regularity could be attributed to frequency as well as to the strength of regularity cues in language acquisition, as proposed by Usage-Based models. The advantage of less complex structures over more complex ones is accounted for by the greater cognitive and linguistic effort required to acquire the latter.

Recent variationist research indicates that grammatical intra-speaker variation (or: optionality) is unproblematic in speech production. Optionality contexts do not coincide with dysfluencies. In this study, we ask a theoretically significant follow-up question about optionality contexts that strongly cue grammatical variant choice: are optionality contexts in which all variants are probabilistically equally likely more problematic than those that strongly cue choice of grammatical variant? After all, unbiased (un-cued or freer) choices are sometimes theorized as being more difficult than biased (cued) ones. We empirically analyzed a subset of the SWITCHBOARD corpus of spoken American English on a turn-by-turn basis. The dataset covers 7,295 conversational turns containing 7,001 optionality contexts (spread over 20 grammatical alternation types), 2,970 filled pauses, and 41,297 unfilled pauses. Contrary to claims in the literature, weak probabilistic cueing does not trigger more production difficulties than strong probabilistic cueing. Unpredictable grammatical choices are not harder than predictable grammatical choices.

We revisit evaluation of logical formulas that allow both uninterpreted relations, constrained to be finite, as well as an interpreted vocabulary over an infinite domain. This formalism was denoted embedded finite model theory in the past. It is clear that the expressiveness and evaluating complexity of formulas of this type depend heavily on the infinite structure. If we embed in a wild structure like the integers with additive and multiplicative arithmetic, logic is extremely expressive and formulas are impossible to evaluate. On the other hand, for some well-known decidable structures, the expressiveness and evaluating complexity are similar to the situation without the additional infrastructure. The latter phenomenon was formalized via the notion of “Restricted Quantifier Collapse”: adding quantification over the infinite structure does not add expressiveness. Beyond these two extremes little was known. In this work we show that the possibilities for expressiveness and complexity are much wider. We show that we can get almost any possible complexity of evaluation while staying within a decidable structure. We also show that in some decidable structures, there is a disconnect between expressiveness of the logic and complexity, in that we cannot eliminate quantification over the structure, but this is not due to an ability to embed complex relational computation in the logic. We show failure of collapse for the theory of finite fields and the related theory of pseudo-finite fields, which will involve coding computation in the logic. As a by-product of this, we establish the first lower bounds for the complexity of decision procedures for several decidable theories of fields, including the theory of finite fields. This article includes material in the extended abstract “Embedded Finite Models: Beyond Restricted Quantifier Collapse,” that appeared in the Logic in Computer Science conference (LICS ’23).

The case-number suffixes of the Western Nilotic language Nuer (Frank 1999) display a remarkable combination of formal simplicity and distributional complexity, which is manifested in: (i) a seemingly erratic form-function mapping that precludes attributing a consistent meaning to the suffixes, and (ii) a wealth of inflection classes only barely differentiated from each other. The suffixes looks as if they were rule-generated, but behave as if they were memorized. I advance a model of inflection combining principal parts, implicational rules, and default inheritance, in which the bulk of the complexity is attributed to the lexical stem, revealing the underlying systematicity behind suffix assignment.

The present study investigated how initial proficiency impacted development in adolescent learners’ L2 speaking. The study reports on a longitudinal study with dense measurements with twelve adolescent L2 English learners. The participants were tested every week throughout their first year of secondary school (30 datapoints). The participants’ learning trajectory was modeled using generalized additive mixed models (GAMMs). Results showed large differences in development between various lexical and syntactic measures and between individual learners. The learners’ initial proficiency had a significant impact on their development. Overall, more periods of growth were observed in lexical measures than in syntactic measures. In line with previous results, some stabilization was observed once learners reached a certain proficiency level, but this stabilization was dependent on task type. Closed tasks lead to a ceiling effect in some measures, whereas more open tasks give learners from various proficiency levels opportunities to demonstrate their L2 English speaking skills.