A theoretical equation has been developed to described the rate of slow crack growth in an ethylene‐hexene copolymer in terms of the basic morphological parameters. These parameters are spacing of the butyl branches, number of tie molecules, and the thickness of the lamellar crystal. Experimentally, the thickness of the lamellae and the long period were determined as functions of the branch density. The calculation of the number of tie molecules is based on the values of the molecular weight and the long period. The model of slow crack growth is based on the rate of disentanglement of the tie molecules. The rate of disentanglement varies inversely with the number of tie molecules and directly with the number of tie molecules that are not pinned by the branches.

Estimation is influenced by a variety of processes: application of heuristics, domain-specific reasoning, and intuitive statistical induction, among them. In this article, we propose the metrics and mapping framework to account for how these processes are integrated to generate estimates. This framework identifies 2 types of information as critical: knowledge of distributional properties (metric knowledge) and knowledge of relative status of individual entities within the distribution (mapping knowledge). Heuristics and domain-specific knowledge are both viewed as cues that contribute to mapping knowledge; intuitive statistical induction is viewed as providing cues to metric properties. Results of 4 experiments illustrate the framework's usefulness for integrating these types of information and for predicting when people emphasize heuristics and when they emphasize domain-specific knowledge.

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In this study, we used process measures to understand how people recall autobiographical memories in response to different word cues. In Experiment 1, participants provided verbal protocols when cued by object and emotion words. Participants also reported whether memories had come directly to mind. The self-reports and independent ratings of the verbal protocols indicated that directly recalled memories are much faster and more frequent than generated memories and are more prevalent when cued by objects than emotions. Experiment 2 replicated these results without protocols to eliminate any demand characteristics or output interference associated with the protocol method. In Experiment 3, we obtained converging results using a different method for assessing retrieval strategies by asking participants to assess the amount of information required to retrieve memories. The greater proportion of fast direct retrievals when memories are cued by objects accounts for reaction time differences between object and emotion cues, and not the commonly accepted explanation based on ease of retrieval. We argue for a dual-strategies approach that disputes generation as the canonical form of autobiographical memory retrieval and discuss the implication of these findings for the representation of personal events in autobiographical memory.Keywords: autobiographical memory, direct retrieval, generative retrieval, memory organization, memory cueing How do people recall autobiographical memories? The literature provides two answers to this question-answers that correspond to two different research approaches. Psychologists who study involuntary memories tend to focus on directly retrieved memories (Berntsen, 1996(Berntsen, , 1998Berntsen & Hall, 2004;Berntsen & Rubin, 2002;Mace, 2004Mace, , 2005Schlagman & Kvavilashvili, 2008). Work on this topic has shown that cues provided by internal and external contexts sometimes combine to trigger an automatic and effortless retrieval of specific autobiographical-events memories. In contrast, researchers who use the Crovitz cue-word method (Crovitz & Schiffman, 1974) and its variants assume that direct retrieval is uncommon (Haque & Conway, 2001). Instead, they stress the importance of either generation or event (re)construction, and they tend to characterize memory retrieval as a deliberate, effortful, and time-consuming activity (Belli, 1998;Botzung, Denkova, Ciuciu, Scheiber, & Manning, 2008;Burgess & Shallice, 1996;Conway, 1990Conway, , 2005 Despite a widespread tendency to equate retrieval processes with retrieval intentions, it has been noted that direct retrieval can occur when participants recall personal memories in response to word cues (e.g., Barsalou, 1988;Berntsen & Rubin, 2004;Brown, 1993;Conway, 1990;Haque & Conway, 2001). Thus, we took the existence of these two retrieval types, direct and generative, 1 as the starting point for our study and designed it to assess the prevalence and impact of direct retrieval when people are required to recall autobiographical memories in respon...

Processes underlying judgments of absolute event frequency were investigated in 3 experiments. In all 3, word pairs consisting of a target (a category label, e.g., CITY) and context (a category exemplar, e.g., London) were presented in a different-or same-context study list. In the different-context condition, each target was paired with a new context on each presentation; in the same-context condition, a target always appeared with the same context. Verbal protocols (Experiment 1) and response times (Experiments 2 and 3) indicate that multiple estimation strategies were used and that strategy selection was related to memory contents. In particular, different-context participants often enumerated, and same-context participants did not. Also, because range information only affected same-context estimates (Experiment 3), it appears that a numerical conversion process was necessary when nonenumeration strategies were used. Judgments of absolute frequency are collected in most experiments concerned with the encoding and representation of event frequency (for reviews see Hasher & Zacks, 1979, 1984; Hintzman, 1976, 1988; Howell, 1973). The research described in this article was aimed at understanding how these judgments are produced. In particular, I argue that participants use multiple strategies when estimating event frequency; that strategy selection is determined, in part, by the contents of memory; and that the magnitude and accuracy of participants' frequency estimates are related to the strategy they select. The multiple-strategy perspective adopted in this article has numerous precedents. It is well established that people use multiple strategies to perform a wide variety of simple and not-so-simple cognitive tasks. Among these are recognition (e.g.

To understand the nature and etiology of biases in geographical judgments, the authors asked people to estimate latitudes (Experiments 1 and 2) and longitudes (Experiments 3 and 4) of cities throughout the Old and New Worlds. They also examined how people's biased geographical judgments change after they receive accurate information ( "seeds" ) about actual locations. Location profiles constructed from the pre-and postseeding location estimates conveyed detailed information about the representations underlying geography knowledge, including the subjective positioning and subregionalization of regions within continents; differential seeding effects revealed between-region dependencies. The findings implicate an important role for conceptual knowledge and plausible-reasoning processes in tasks that use subjective geographical information.Geographical units like cities, provinces, countries, and continents are almost always irregular in shape and area; in their orientation relative to the cardinal points of the compass; and in their alignment relative to adjacent geographical units. Yet they also fit into a simple hierarchical scheme in which towns and cities are nested within provinces, provinces within countries, and countries within continents. It is obvious that people know about the spatial aspects of world geography as well as the hierarchical relations among geopolitical entities, and it is equally obvious that their knowledge is imperfect. What is less clear is how imperfect geographical knowledge is represented and how it is coordinated and weighed when used in making judgments.The tendency to normalize irregular shapes, combined with the tendency to develop a conceptual understanding of the hierarchical relations between geographical units, implies that geographical intuitions can be biased. In this article, we focus on understanding what geographical biases imply about how people encode, store, and use geographical knowledge in making judgments about locations. We take the position that most geographical biases result from plausible-reasoning processes that operate on complex beliefs about global geography and that few biases result from distortions of perceptually based representations. We conclude that the "mental map" metaphor is a misleading analogy for the representation of geographical knowledge and that the plausible-reasoning framework can account for much of the data in the subjective geography literature.We explored the nature of geographical biases by asking This research was supported by grants from the Natural Sciences and Engineering Research Council of Canada. We thank Ed Comell and Peter Dixon for thorough and thoughtful reading of a draft. We also thank Javier Movellan for suggesting that the seeding method could be used to study subjective geography.

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