An Aggregate of Spear Points from Atoka County, Oklahoma

Nine spear points were reported from a farm in northwestern Atoka County, Oklahoma. This aggregate of points appeared to bean isolate as no other prehistoric material was found in the vicinity. The following study discusses the setting and nature of the specimens, stylistic attributes of the spear points and their age, technological and functional characteristics of the pieces, and whether these items represent caching behavior

The effects of after-school physical activity and adult encouragement on adolescents

Includes bibliographical references

Counterbalancing for serial order carryover effects in experimental condition orders

Reactions of neural, psychological, and social systems are rarely, if ever, independent of previous inputs and states. The potential for serial order carryover effects from one condition to the next in a sequence of experimental trials makes counterbalancing of condition order an essential part of experimental design. Here, a method is proposed for generating counterbalanced sequences for repeated-measures designs including those with multiple observations of each condition on one participant and self-adjacencies of conditions. Condition ordering is reframed as a graph theory problem. Experimental conditions are represented as vertices in a graph and directed edges between them represent temporal relationships between conditions. A counterbalanced trial order results from traversing an Euler circuit through such a graph in which each edge is traversed exactly once. This method can be generalized to counterbalance for higher order serial order carryover effects as well as to create intentional serial order biases. Modern graph theory provides tools for finding other types of paths through such graph representations, providing a tool for generating experimental condition sequences with useful properties

Traditional and new principles of perceptual grouping

Perceptual grouping refers to the process of determining which regions and parts of the visual scene belong together as parts of higher order perceptual units such as objects or patterns. In the early 20th century, Gestalt psychologists identified a set of classic grouping principles which specified how some image features lead to grouping between elements given that all other factors were held constant. Modern vision scientists have expanded this list to cover a wide range of image features but have also expanded the importance of learning and other non-image factors. Unlike early Gestalt accounts which were based largely on visual demonstrations, modern theories are often explicitly quantitative and involve detailed models of how various image features modulate grouping. Work has also been done to understand the rules by which different grouping principles integrate to form a final percept. This chapter gives an overview of the classic principles, modern developments in understanding them, and new principles and the evidence for them. There is also discussion of some of the larger theoretical issues about grouping such as at what stage of visual processing it occurs and what types of neural mechanisms may implement grouping principles

A situated cultural approach for cross-cultural studies in IS

Cultural anthropology seeks to understand the similarities and differences among groups of people in the contemporary world. Although there are many different models of national culture, most IS research has tended to rely almost solely on Hofstede’s cultural model (Keil et al., 2000; Straub, 1994; Tan et al., 1995; Watson et al., 1994; Myers and Tan, 2002; Kirkman et al. 2006).). This paper, provides a comprehensive framework of situated culture approach to study culture within IS discipline. This is achieved via an articulation of Structuration Theory and the provision of an approach to study cross-cultural phenomena within IS discipline. The paper proposes two main components of the Structuration Theory based analysis model which is proposed as a way to study culture within IS discipline. First, the paper presents ideas behind the practice lens for studying the use of technology, as proposed by Orlikowski (2000). Secondly, the paper presents a Structurational analysis approach as detailed by Walsham (2002). The paper argues that using a practice lens contributes to identifying the mediated shared structures between actors through understanding the actions of the actors within the phenomena. Then, using a Structurational analysis approach contributes to identifying the cultural dimensions that are embedded in the identified mediated shared structures