Showing papers in "Quality & Quantity in 2007"

A caution regarding rules of thumb for variance inflation factors.

Abstract: The Variance Inflation Factor (VIF) and tolerance are both widely used measures of the degree of multi-collinearity of the ith independent variable with the other independent variables in a regression model. Unfortunately, several rules of thumb – most commonly the rule of 10 – associated with VIF are regarded by many practitioners as a sign of severe or serious multi-collinearity (this rule appears in both scholarly articles and advanced statistical textbooks). When VIF reaches these threshold values researchers often attempt to reduce the collinearity by eliminating one or more variables from their analysis; using Ridge Regression to analyze their data; or combining two or more independent variables into a single index. These techniques for curing problems associated with multi-collinearity can create problems more serious than those they solve. Because of this, we examine these rules of thumb and find that threshold values of the VIF (and tolerance) need to be evaluated in the context of several other factors that influence the variance of regression coefficients. Values of the VIF of 10, 20, 40, or even higher do not, by themselves, discount the results of regression analyses, call for the elimination of one or more independent variables from the analysis, suggest the use of ridge regression, or require combining of independent variable into a single index.

Validity and Qualitative Research: An Oxymoron?

Abstract: Although the importance of validity has long been accepted among quantitative researchers, this concept has been an issue of contention among qualitative researchers. Thus, the first purpose of the present paper is to introduce the Qualitative Legitimation Model, which attempts to integrate many of the types of validity identified by qualitative researchers. The second purpose of this article is to describe 24 methods for assessing the truth value of qualitative research. Utilizing and documenting such techniques should prevent validity and qualitative research from being seen as an oxymoron.

A call for qualitative power analyses.

Abstract: The purpose of this paper is to emphasize the importance of sampling and sample size considerations in all qualitative research. Such considerations would help qualitative researchers to select sample sizes and sampling designs that are most compatible with their research purposes. First, we discuss the importance of sampling in qualitative research. Next, we outline 24 designs for selecting a sample in qualitative research. We then discuss the importance of selecting a sample size that yields data that have a realistic chance of reaching data saturation, theoretical saturation, or informational redundancy. Based on the literature, we then provide sample size guidelines for several qualitative research designs. As such, we provide a framework for making sampling and sample size considerations in interpretive research.

Action Research is Similar to Design Science

Abstract: In management information systems (MIS) action research is long considered as promising but low-level research approach. It has an utmost relevance because action researchers are working with practitioners to solve the important practical problem. Design science outlined some years ago is just winning a wider audience. Action research was traditionally classified into qualitative research methods. But it seems to be the “wrong” home of action research. We shall show that after comparison of the seven aspects: concrete results of the study, knowledge produced, activities, the intent and the nature of a study, the division of labor in a study and generation, use and test of knowledge, the concordance between the characteristics of action research on the one hand and of design science on the other hand is very good. Hence, action research and design science should next be considered as similar research approaches, and this is a turning point in the history of both action research and design science.

Ordinal Methodology in the Analysis of Likert Scales

Abstract: Likert scales are widely used in survey studies for attitude measuring. In particular, the questionnaires propagated by the SERVQUAL approach are based on Likert scales. Though the problem of attitude suggests an ordinal interpretation of Likert scales, attitude survey data are often evaluated with techniques designed for cardinal measurements. The present paper discusses the interpretation of scales for attitude measuring and gives a survey of data analysis techniques under the proper ordinal understanding.

Modeling society with statistical mechanics : an application to cultural contact and immigration

Abstract: We introduce a general modeling framework to predict the outcomes, at the population level, of individual psychology and behavior. The framework prescribes that researchers build a cost function that embodies knowledge of what trait values (opinions, behaviors, etc.) are favored by individual interactions under given social conditions. Predictions at the population level are then drawn using methods from statistical mechanics, a branch of theoretical physics born to link the microscopic and macroscopic behavior of physical systems. We demonstrate our approach building a model of cultural contact between two cultures (e.g., immigration), showing that it is possible to make predictions about how contact changes the two cultures.

Evaluating the Validity of Self-Reported Deviant Behavior Using Vignette Analyses

Abstract: In this paper, the validity of vignette analyses of various forms of deviant behavior in the presence of opportunities is analyzed on the basis of ideas derived from cognitive psychology. Abelson’s Script Theory together with insights into human memory of visual and verbal information, allow the assumption that vignette analyses using visual stimuli are valid measures of deviant behavior in particular. The study includes an empirical examination of these ideas (n = 450). Nonparticipant observations and vignette analyses with visual and verbal material were carried out with regard to three forms of deviant behavior occurring in the presence of opportunities presenting themselves in everyday life. Observed and self-reported frequencies of deviant behavior or deviant intentions were counted and cross-tabulated. Log-linear analyses with dummy coding using observation data as reference category were run. Data analyses yielded the result that frequencies of deviant behavior were related to the techniques of data collection under consideration. Especially vignette analyses of the return of ‘lost letters’ that use both visual and verbal stimuli overestimate ‘actual’ (i.e. observed) return rates. This result is discussed with regard to the underlying methodological assumptions as well as its implications.

How Qualitative Data Analysis Software may Support the Qualitative Analysis Process

Abstract: The last decades have shown large progress in the elaboration of procedures for qualitative data analysis and in the development of computer programs to support this kind of analysis. We believe, however, that the link between methodology and computer software tools is too loose, especially for a novice qualitative researcher. It is very unclear to select the proper functions and tools as a support in a specific phase of analysis. In texts, you will find a description of the steps of qualitative analysis, and in separate texts computer tools are presented, but what function or tool to use in what phase of analysis is hardly discussed. In this article, we will elaborate the phases of the grounded theory approach and indicate which of the tools of the computer program Kwalitan is to be used in each of the steps and procedures. We will also show how the functions of the computer program may be used when doing a qualitative analysis according to three other approaches, namely summarizing analysis, ethnographic analysis and narrative analysis.

Investigating the value of information sharing in multi-echelon supply chains

Abstract: Under the structure of multiple business entities, supply chain management (SCM) offers the external and internal integration of business processes in enterprises. The most important objective of SCM is to enhance the supply chain performance such as reinforcing the service level and increasing profit as well as reducing order cycle time and inventory. In recent years, due to the advancement of information technology, enterprises can manage the product flow and the information flow via economical and efficient mechanisms. The well-organized information sharing can enhance the supply chain performance and allow enterprises to refine their strategies of supply chain in order to maximize their profits. The previous studies pointed out the positive effect of information sharing on the efficiency of supply chain. However, relatively little literature focuses on the performance analysis for multi-echelon supply chain with various information sharing scenarios. By using the simulation technique, this paper models different scenarios of information sharing, and further analyzes the impacts of information quality on multi-echelon supply chain performance. In addition, this paper employs Data Envelopment Analysis (DEA) to integrate multiple performance measures to ensure the information sharing scenarios with enhanced performance.

Of songs and men: a model for multiple choice with herding

Abstract: We propose a generic model for multiple choice situations in the presence of herding and compare it with recent empirical results from a Web-based music market experiment. The model predicts a phase transition between a weak imitation phase and a strong imitation, ‘fashion’ phase, where choices are driven by peer pressure and the ranking of individual preferences is strongly distorted at the aggregate level. The model can be calibrated to reproduce the main experimental results of Salganik et al. (Science, 311, 854–856 (2006)); we show in particular that the value of the social influence parameter can be estimated from the data. In one of the experimental situation, this value is found to be close to the critical value of the model.

From 2000 Bush–Gore to 2006 Italian elections: voting at fifty-fifty and the contrarian effect

Abstract: A sociophysical model for opinion dynamics is shown to embody a series of recent western hung national votes all set at the unexpected and very improbable edge of a fifty-fifty score. It started with the Bush–Gore 2000 American presidential election, followed by the 2002 Stoiber–Schroder, then the 2005 Schroder–Merkel German elections, and finally the 2006 Prodi-Berlusconi Italian elections. In each case, the country was facing drastic choices, the running competing parties were advocating very different programs and millions of voters were involved. Moreover, polls were given a substantial margin for the predicted winner. While all these events were perceived as accidental and isolated, our model suggests that indeed they are deterministic and obey to one single universal phenomena associated to the effect of contrarian behavior on the dynamics of opinion forming. The not hung Bush–Kerry 2004 presidential election is shown to belong to the same universal frame. To conclude, the existence of contrarians hints at the repetition of hung elections in the near future.

Quality and Quantity in Test Validity: How can we be Sure that Psychological Tests Measure what they have to?

Abstract: During the twentieth century, many authors have offered their contributions to the controversial subject of test validity. Thus, the concept of validity seems to be quite a simple idea until one looks at the literature on the subject. Validity can be defined as “the degree to which the test actually measures what it purports to measure,” but the question of how to define validity and how to test it is both an old question and a never-ending story. We have to deal with it every time we are asked to use a test that already exists or to construct a new one. Therefore, the article aims at dealing with test validity in order to point out the different (qualitative and quantitative) aspects of validity, which have emerged from empirical research and theoretical reflections. It is thought as a critical review which can be useful both to theoretically oriented and practically inclined psychologists.

Fuzzy Control Chart A Better Alternative for Shewhart Average Chart

Abstract: This paper through a real illustrative example and a power test shows that designing a fuzzy control chart for process average of a continuous (variable) quality characteristic with a warning line is a better alternative to Shewhart \(\bar{X}\) chart in many respects, like providing better neural view to inspectors, offering different strategic options for company to choose, detecting the desire shifts more quickly, and more sensibility to small shifts without any complexity augmentation to the chart.

Developing and Implementing a Selection Model for Bedding Chain Retail Store Franchisee Using Delphi and Fuzzy AHP

Abstract: This work presents a Fuzzy Analytic Hierarchy Process (Fuzzy AHP) model that adopts several important criteria. A questionnaire based on selection criteria identified from pertinent literature and interviews with experts is designed using the modified Delphi Technique and then sent to experts and decision makers. Major selection criteria are then analyzed and ranked using Fuzzy AHP. The proposed selection model not only enables a franchiser to select franchisees more objectively, but also be apply to other brand bedding company chain stores, thus enhancing commercial operations.

Using Print Media Indicators in Management Fashion Research

Abstract: Quantitative empirical research into ‘management fashions’ or ‘organization concepts’ is dominated by studies using print media indicators (PMI). Such research builds on the simple premise that the number of publications on an organization concept in the course of time reflects managerial interest in this concept. However, whilst PMI may be fruitfully used to study management fashions, this use is less straightforward than appears commonly assumed. We aim to fulfil the need for a methodological paper discussing the possibilities and limitations of using PMI. Thereby we draw on insights from bibliometrics and management fashion research, including our own ongoing research.

Optimising a probabilistic model of the development of play in soccer

Abstract: We present a probabilistic model based on the one developed by Hernandez Mendo and Anguera (Revista de Psicologica Social, 16(1), 71–93, 2001). Here we have tried to break down the interaction contexts that the opposing teams are able to generate and transform during the game. We are aware that a given player or team does not produce consistent behaviour in similar situations. However, a degree of uncertainty is assumed to exist regarding whether the results obtained are a specific function of the analysis used. In order to carry out this research a category system which optimized that used in the previous model was developed. This system should enable the interaction between teams to be observed within the actual play of a soccer game. A lag sequential analysis was performed on the basis of a coding of the behavioural flow. After describing the behavioural patterns obtained a probabilistic model of the development of play in soccer is proposed.

Collecting Event Histories with TrueTales: Techniques to Improve Autobiographical Recall Problems in Standardized Interviews

Abstract: This article deals with the challenges autobiographical recall processes present to validity of events and their dates in the collection of life histories in standardized interviews. Effective interviewing techniques should support the idiosyncratic cognitive structure and the reconstructive memory processes of autobiographical memory by allowing to flexibly explore the interconnections between memories. We describe the techniques and strategies of interviewing and data recording used in the German Life History Study, namely modularization, forward recall and single case data edition. We introduce TrueTales, a CATI-Program designed to support memory and communication in the interview, and results of its experimental evaluation. TrueTales personalizes instructions, questions and probes and permits controlled flexibility in dealing with individual biographies and recall strategies. Working with a calendar-based time-line, it yields more complete, consistent and valid event histories. Finally, we discuss implications for standardized interviewing practices and the concept of standardization.

Reciprocity, multiplexity, and exchange: Measures

Abstract: We introduce measures and statistical tests for multiplexity and exchange that are modeled on similar ideas developed for reciprocity quite early in the history of social network research. As properties of a multi-relation network, multiplexity, and exchange have almost as ancient a history as reciprocity, but have not been as intensively investigated from a methodological perspective. Multiplexity refers to the extent to which two ties, for example, advice and friendship, coincide over population; that is, do respondents name the same people as friends as the persons they nominate as individuals from who they seek advice. Exchange refers to the extent to which a tie of one type directed from person i to person j is returned by a tie of another type from j to i. We conceive of the current paper as the first part of a two-part paper, wherein the second part explores specific theoretical models for multiplexity and exchange.

Destination Choice: An Important - Satisfaction Analysis

Abstract: In the last decade under the effects of globalization, all destinations have had experienced significant changes under different national and/or international pressures. This is especially the case for developing countries like Turkey. With cultural, economic and social aspects in the tourism sphere, countries are competing with each other by emphasizing their differences. This research examines the perceptions of tourists in the Antalya Region of Turkey in terms of importance and satisfaction. The sample consisted of 645 tourists who came to Antalya in 2001. This research presents valuable information to the tourism sector about tourist preferences through its use of importance-satisfaction analysis.

A Note Regarding the Condition Number: The Case of Spurious and Latent Multicollinearity

Abstract: The detection of multicollinearity in econometric models is usualy based on the so-called condition number (CN) of the data matrix X. However, the computation of the CN, which is the greater condition index, gives misleading results in particular cases and many commercial computer packages produce an inflated CN, even in cases of spurious multicollinearity, i.e. even if no collinearity exists when the explanatory variables are considered. And this is due to the very low total variation of some columns of the transformed data matrix, which is used to compute CN. On the other hand, we may have the problem of latent multocollinearity which can be revealed by additionally computing a revised CN. With all these in mind, we figure out the ill-conditioned situations, suggesting some practical rules of thumb to face such problems using a single diagnostic in a fairly simple procedure. It is noted that this procedure is not mentioned in the relevant literature.

Social Distance, Respondent Cooperation and Item Nonresponse in Sex Survey

Abstract: This paper examines the ways in which the number of item nonresponses is determined by social distance and/or interview rapport, with a focus on responses of “refusal” and “don’t know”, implying the respondent’s lack of willingness and ability to provide substantive responses to sensitive questions. The data analyzed were from 39 self- administered questions concerning sexual attitudes and behaviors in the 2002 Taiwan Social Change Survey for module “Family and Changing Gender Role”. Poisson Regression in 2-level Hierarchical Linear Model was employed to enhance the accuracy of the analysis of the accumulation of “don’t know” and “refusal” responses. The results showed that respondent cooperation significantly decreased the number of both “don’t know” and “refusal” replies. The decrease was not conditioned by any kind of social distance. Age and education distances have respectively negative and positive effect on the number of “don’t know” and “refusal” answers. The married–married interview produced more “don’t know” and “refusal” than other paired interview types. The larger the ethnicity distance is, the more “refusal” appears. The substantial findings imply that the effects of social-distance and rapport (respondent cooperation) on the number of item nonresponses deserve more attention in research on survey methodology. The divergent findings on gender-distance effect and marital-status effect, however, call for replication studies in the future.

Cumulative culture and explosive demographic transitions

Abstract: A demographic transition is a change in the pattern of growth of a population. Human history records several kinds of such transitions, e.g., from stability to growth or between different kinds of growth. Culture is often implied as the main fuel of demographic transitions, but theorizing is so far limited to verbal arguments. Here we study two simple formal models in which population size and the amount of culture in a population influence each other’s dynamics. The first model has two regimes: an equilibrium regime in which both population size and amount of culture reach stable values, and an explosive regime in which both variables increase exponentially without bound. A transition between these regimes is caused by changes in parameters that describe the accuracy of cultural transmission and the interaction between demography and culture. The second model suggests that a transition from extensive to intensive accumulation of culture may derive from a qualitative change in how individuals cooperate to create culture.

Selection of Indicators for the Interaction Term in Structural Equation Models with Interaction

Abstract: Kenny and Judd (1984, Psychological Bulletin 96: 201–210) suggested using structural equation models to model interaction effects since they allow correction for measurement error. They proposed using all possible products of the indicators of the two interacting variables as indicators for the interaction term. Joreskog and Yang (1996, Advanced Structural Equation Modeling. Mahwah, NJ: Lawrence Erlbaum, pp. 57–88.) defended that this is not necessary; one product variable is sufficient to estimate the interaction effect. However, they did not specify which indicators should be chosen if there is more than one possibility. We prove that the optimal choice is to select the indicators with the highest reliabilities. But this is only true if certain assumptions hold. We go on to show that one can get very different results depending on the indicators chosen for the interaction term if the indicators are not congeneric which is often the case. These methodological arguments will be illustrated by a study of the purchasing or boycotting of certain products for environmental reasons.

LINEX Loss Functions with Applications to Determining the Optimum Process Parameters

Abstract: In the classical Taguchi quality model, the symmetric quadratic loss function has been used to measure the loss of quality. However, there are a number of situations in which the symmetric quadratic loss may be inappropriate. In this paper, we proposed an asymmetric loss function, called linear exponential (LINEX) loss function, to determine optimum process parameters for the product quality. When the coefficient of LINEX loss function is small, it will be close to the quadratic loss. Moreover, the trade-off problem between quality and cost will be discussed.

Applied Product Capability Analysis Chart in Measure Step of Six Sigma

Abstract: This paper will apply product capability analysis chart PCAC in Measure step of Six Sigma. Because the test model is sampling, sampling error must be consider. Thus minimum value will be used to evaluate process capability. Besides the paper used minimum value to evaluate process capability, we also applied the concept of Six Sigma in PCAC and construct PCAC of Six Sigma standard. Finally, PCAC of Six Sigma standard will apply in Six Sigma project of Offset Ratchet Wrenches which manufactured by Y company.

Can Findings of Qualitative Research in Education be Generalized

Abstract: Most qualitative researchers do not recommend generalization from qualitative studies, as this research is not based on random samples and statistical controls. The objec- tive of this study is to explore the degree to which in-service teachers understand the con- troversial aspects of generalization in both qualitative and quantitative educational research and as to how this can facilitate problems faced by the teachers in the classroom. The study is based on 83 participants who had registered for a 10-week course on 'Method- ology of Investigation in Education' as part of their Master's degree program. The course is based on 11 readings drawing on a philosophy of science perspective (positivism, con- structivism, Popper, Kuhn, Lakatos). Course activities included written reports, class room discussions based on participants' presentations, and written exams. Based on the results obtained it is concluded: (1) almost 91% of the teachers agreed that external generalization in a different social context is feasible; (2) almost 63% of the participants used a fairly incon- sistent approach, that is in a theoretical context agreed that qualitative research cannot be generalized and still when asked with respect to the experience of two particular teachers, agreed that generalization was possible; (3) almost 28% of the participants used a consis- tent approach. Some of the reasons provided by the participants as to why generalization was feasible are discussed. An analogy is drawn with respect to Piaget's methodology, viz., it was not based on random samples or statistical treatments and still his oeuvre has been generalized (criticisms not withstanding) in both the psychology and educational literature.

Estimating and Testing Process Precision with Presence of Gauge Measurement Errors

Abstract: Process capability indices have been widely used in the manufacturing industry. Those capability indices, quantifying process potential and performance, are important for any successful quality improvement activities and quality program implementation. Because of the simplicity and easy of understanding, the precision index Cp has gained its popularity for measuring process consistency. However, the quality of data on the process characteristics relies very much on the gauge measurement. Conclusions about capability of the process just only based on the single numerical value of the index are not reliable. In this paper, we not only conduct the performance of the index Cp with gauge measurement errors, but also present adjusted confidence interval bounds and critical values for capability testing purpose of Cp with unavoidable measurement errors. Our research would help practitioners to determine whether the factory processes meet the capability requirement, and make more reliable decisions.

Control Charts for One-sided Capability Indices

Abstract: There are many industrial product characteristics are desired to be the bigger the best and the smaller the best. The two well-know processes capability indices Cpl and Cpu, which measure larger-the-better and smaller-the-better process capabilities. Obviously, the formulae for the two indices Cpl and Cpu are easy to understand and straightforward to apply. Thus, indices Cpl and Cpu have been utilized by a number of Japanese companies and the U.S. automotive industry by Ford Motor Company. Boyles (1991, Journal of Quality Technology. 23: 17–26) and Spring (1995, Total Quality Management 6(3): 427–438.) point out that as soon as \(\overline{X}\) and S control charts are in statistical control, the control charts of process capability indices can be used to monitor the quality of process. In the previous, we know that if the process is not in control, the process capability index control chart can be used to monitor the differences of process capability, and as soon as the process is in control the stable process capability can be identified. Therefore, process capability index control chart not only can be used to monitor the stability of process’s quality but also can be used to monitor the quality of process. Since Boyles (1991, Journal of Quality Technology 23: 17–26.) and Spiring (1995, Total Quality Management 6(1): 21–33.) had had research about control chart of the bilateral specification index Cpm., but there are many kinds of products, which meet unilateral quality specification. Therefore, we will construct the control chart of unilateral specification index Cpl and Cpu to monitor and evaluate the stability of process and process capability.

The Brand Choice Model of Wine Consumers: A Multinomial Logit Model

Abstract: The objective of this study is to determine factors influencing brand preferences of wine consumers in the Marmara region where viniculture and wine production is so important in Turkey. First, the consumers’ preferences survey has been conducted with 1022 persons in the region randomly selected and evaluated. Then, the informative factors influencing brand preferences collected in these surveys have been determined by the multinomial logit model. A lot of independent variables have been used in the multinomial logit model, but, because some independent variables were not found as significant according to Likelihood Ratio test, these variables are not included in the multinomial logit analysis. Six important factors influencing wine brand preferences have been determined. These factors are brand change causes of consumers, occupation of consumers, marital status of consumers, birthplace of consumers, income of consumers and gender of consumers. In addition, whether the wine brand preferences are independent, has been tested with Testing Independence of Irrelevant Alternatives of Hausman. According to this test, it has been found that the wine brand preferences are independent.

Investigating the Number of Non-linear and Multi-modal Relationships Between Observed Variables Measuring Growth-oriented Atmosphere

Abstract: This study investigates the number of non-linear and multi-modal relationships between observed variables measuring the Growth-oriented Atmosphere. The sample (N = 726) represents employees of three vocational high schools in Finland. The first stage of analysis showed that only 22% of all dependencies between variables were purely linear. In the second stage two sub samples of the data were identified as linear and non-linear. Both bivariate correlations and confirmatory factor analysis (CFA) parameter estimates were found to be higher in the linear sub sample. Results showed that some of the highest bivariate correlations in both sub samples were explained via third variable in the non- linear Bayesian dependence modeling (BDM). Finally, the results of CFA and BDM led in different substantive interpretations in two out of four research questions concerning organizational growth.