Measurement of non-randomness in spatial distributions

Summary The measurement of departure from randomness in spatial distributions has widespread application in ecological work. Several “indices of non-randomness” are compared with regard to their dependence on sample number, sample size and density. Criteria for the best choice of index for specific situations are discussed. A new coefficientC _x is proposed for use with positively contagious distributions and tests of significance are given. WhenC _x and another index (S ²/m−1) are used for positive and negative contagion respectively, values ranging from −1 through 0 (random) to +1 are obtained, regardless of sample number, sample size or density.     

Machine learning and design of experiments with an application to product innovation in the chemical industry

Industrial statistics plays a major role in the areas of both quality management and innovation. However, existing methodologies must be integrated with the latest tools from the field of Artificial Intelligence. To this end, a background on the joint application of Design of Experiments (DOE) and Machine Learning (ML) methodologies in industrial settings is presented here, along with a case study from the chemical industry. A DOE study is used to collect data, and two ML models are applied to predict responses which performance show an advantage over the traditional modeling approach. Emphasis is placed on causal investigation and quantification of prediction uncertainty, as these are crucial for an assessment of the goodness and robustness of the models developed. Within the scope of the case study, the models learned can be implemented in a semi-automatic system that can assist practitioners who are inexperienced in data analysis in the process of new product development.     

AN EXPERIMENTAL EVALUATION OF THE RELATIONSHIP OF UNCERTAINTY IN THE ENVIRONMENT TO INFORMATION USED BY DECISION MAKERS*

This paper discusses the relationship between uncertainty in a decision making environment and the desired characteristics of information used for decision making. The work is aimed at providing a better understanding of the variables that affect the design of Management Information Systems. An experiment was conducted using an inventory simulator. The subjects could decide on inventory control variables and the amount and type of information to be used in monitoring system performance. The demand for inventory was an external random variable under the control of the experimenter. The experiment investigated how different demand variances affected the decision information used, the decisions made, and the resulting decision effectiveness (cost.) It was found that decision review frequency was not affected by demand variability. However, age and degree of summary of information used were greatly affected. Subjects exposed to high variability used data with a shorter history and a higher level of detail than those exposed to low variability. It was also found that the number of reports used increased from the low to middle variance group, then decreased at very high variance. Subjects tended to “give-up” on their information system at high variance, and they relied on additional safety stock to prevent frequent stockouts. Finally, the correlation between the information used and decision effectiveness as measured by cost was low. This result was contrary to the subjects' beliefs that more and better information produced “better” decisions. It indicates that although variability may strongly affect preferences for different types of information, the information used may not in turn affect decision performance.     

RETURN ON INVESTMENT AS A CRITERION FOR INVENTORY MODELS

In the past most inventory formulations have utilized cost minimization or profit maximization as an optimizing criterion. When viewed from the standpoint of the owner or investor, maximizing the return on investment (ROI) is an appropriate criterion for many types of inventories. This paper proposes ROI as a criterion for inventory models and derives optimal reorder rules for some common assumptions. An economic order quantity that differs greatly from the traditional formulas is discussed. The paper also enumerates the conditions under which ROI is an appropriate criterion and contrasts it to the traditional cost minimization and profit maximization criteria.     

Networks,case managers,and the job-search experiences of unemployed people

Employment services are commonly provided in network settings, but it is rare to find social policy analyses of how unemployed people search for jobs through networks. In a germinal analysis of social networks and employment, Mark Granovetter argued that “weak ties” (less familiar contacts) are more important to finding employment than are “strong ties” (family and friends). This is because weak ties provide more novel job-relevant information. Scholarship since Granovetter has predominantly supported the opposite argument, namely, that strong ties are more important for the unemployed, because they are more plentiful and thus provide more information in aggregate. Findings are also generally coloured by the focus being on “informal” networks or personal contacts. “Formal” networks, as represented most cogently by employment service providers, are absent or underestimated in most social network studies. On the basis of a qualitative study of 80 long-term unemployed people in Australia, incorporating analysis of both informal and formal networks, we argue that although “strong informal” ties are vital to job search, it is also important to consider “weak formal” ties, which can be complementary if and where service organizations are able to supply positive case management experiences.     

Switching commuters from car to public transit: a micro modelling approach

This paper examines the perceptions and values of commuters in Toronto concerning public transit and the private car. Interviews were conducted at an office location readily accessible by car, bus or subway. Respondents were characterized by their predominant commuting mode and provided ratings of the perceived benefits of the modes available. Respondents then completed a conjoint analysis task designed to estimate their trade-offs, or the extent to which they were prepared to sacrifice on one aspect of a commuting journey in order to gain on another. The conjoint analysis used a fractional factorial design allowing main effects and two way interactions to be estimated.The conjoint analysis methodology is used to develop benefit segments and evaluate methods of marketing public transit.     

A standard methodology for the analysis,recording, and control of verbal behavior

The Analysis of Verbal Behavior - Lack of a standard methodology has been one of the major obstacles preventing advancement of behavior analytic research in verbal behavior. This article presents a...     

A Preliminary Study of the Role of Attunement in Adult Psychotherapy

This paper presents the results of a preliminarystudy on the recognition of affect attunement in adultpsychotherapy. Brief extracts from six videotapedtherapy sessions were shown to experienced clinicians, who were asked to judge whether the therapistwas attuned to the client/patient or not. Clear examplesof attunement and non-attunement were obtained and thesewere then shown to a sample of postgraduate social work trainees. The trainee resultsshowed none of the consistency of the cliniciansjudgments: 67% (n = 21) were undecided about the exampleof attunement, with only 19.3% (n = 6) giving responses which corresponded with those of theclinicians. For the non-attuned extract, just over athird gave a response which coincided with theclinicians, with 42% (n = 13) undecided. The resultswere used to develop a model for future research on affectattunement, which should provide the basis for thedevelopment of strategies for teaching the attunementskills which may be required by therapists.     

CHILDHOOD FAMILY STRUCTURE AND ENTRY INTO FIRST MARRIAGE

The present study uses data from the National Survey of Families and Households to examine socialization and stress hypotheses which link family structure during childhood with entry into first marriage. Results from logistic regressions show evidence for both hypotheses. The findings show that years lived with mother only during early childhood and change from both biological parents to mother-only families significantly increase chances for delayed marriage for whites. One other factor, being born into a mother-only family, increased chances for early marriage. Thus, for whites, we found counteracting influences of family structure during childhood on marriage. For blacks, the family structure measures, overall, show little effect on entry into marriage. Finally, we found that family structure had a stronger impact for those born in the 1940s than for those born later.