THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

Social scientists often estimate models from correlational data, where the independent variable has not been exogenously manipulated; they also make implicit or explicit causal claims based on these models. When can these claims be made? We answer this question by first discussing design and estimation conditions under which model estimates can be interpreted, using the randomized experiment as the gold standard. We show how endogeneity – which includes omitted variables, omitted selection, simultaneity, common-method variance, and measurement error – renders estimates causally uninterpretable. Second, we present methods that allow researchers to test causal claims in situations where randomization is not possible or when causal interpretation could be confounded; these methods include fixed-effects panel, sample selection, instrumental variable, regression discontinuity, and difference-in-differences models. Third, we take stock of the methodological rigor with which causal claims are being made in a social sciences discipline by reviewing a representative sample of 110 articles on leadership published in the previous 10 years in top-tier journals. Our key finding is that researchers fail to address at least 66% and up to 90% of design and estimation conditions that make causal claims invalid. We conclude by offering 10 suggestions on how to improve non-experimental research.

On making causal claims : A review and recommendations

The main purpose of this paper is to draw attention to some facts and ideas that perhaps can help to identify problems or fields for development and research within the evaluation of training. Topics for group discussion are preceded by material on some basic concepts of evaluation and educational measurement. The ratio scale, the interval scale, the ordinal scale, and the nominal scale are given as examples of kinds of scales used in educational measurement; the problem of norms is discussed; potential purposes of evaluation or educational measurement are outlined; and some characteristics of a good measuring instrument are explained. The author also defends the inclusion of evaluation as an Integral part of a model for planning and carrying out educational programs. (BW) *********************************************************************** Documents acquired by ERIC include many informal unpublished * materials not available from other sources. ERIC makes every effort * * to obtain the best copy available. Nevertheless, items of marginal * * reproducibility are often encountered and this affects the quality * of the microfiche and hardcopy reproductions ERIC makes available * * via the ERIC Document Reproduction Service (EDRS). EDRS is not * responsible for the quality of the original document. Reproductions * * supplied by EDRS are the best that can be made from the original. *********************************************************************** U S DEPARTMENT OF HEALTH, EDUCATION &WELFARE NATIONAL INSTITUTE OF EDUCATION EVALUATION OF TRAINING

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Evaluation of Training.

textPrior studies have emphasized that structural attributes are crucial to simultaneously pursuing exploration and exploitation, yet our understanding of antecedents of ambidexterity is still limited. Structural differentiation can help ambidextrous organizations to maintain multiple inconsistent and conflicting demands; however, differentiated exploratory and exploitative activities need to mobilized, coordinated, integrated, and applied. Based on this idea, we delineate formal and informal senior team integration mechanisms (i.e. contingency rewards and social integration) and formal and informal organizational integration mechanisms (i.e. cross-functional interfaces and connectedness) and examine how they mediate the relationship between structural differentiation and ambidexterity. Overall, our findings suggest that the previously asserted direct effect of structural differentiation on ambidexterity operates through informal senior team (i.e. senior team social integration) and formal organizational (i.e. cross-functional interfaces) integration mechanisms. Through this richer explanation and empirical assessment, we contribute to a greater clarity and better understanding of how organizations may effectively pursue exploration and exploitation simultaneously to achieve ambidexterity.

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Structural Differentiation and Ambidexterity: The Mediating Role of Integration Mechanisms

The Sage Encyclopedia of Social Science Research Methods

Orientation: Beneficiary contact moderates the relationship between authentic leadership and work engagement. Research purpose: The objective of this study was to examine the moderating effect of the breadth, depth and frequency of employee interaction with the beneficiaries of their work on the positive impact of authentic leadership on work engagement. Motivation for the study: Investigating the boundary conditions of the relationship between leaders and followers is vital to enhance the positive effect of leadership. Authentic leadership has not previously been examined with respect to beneficiary contact as a specific situational factor. The researchers therefore set out to ascertain whether beneficiary contact has a strengthening or weakening effect on the impact of authentic leadership on work engagement. Research design, approach and method: The researchers administered the Authentic Leadership Questionnaire (ALQ), the Utrecht Work Engagement Scale (UWES-9) and Grant’s scale on Beneficiary Contact. Main findings: The findings showed that beneficiary contact had a weakening effect on the positive relationship between authentic leadership and work engagement. Practical/managerial implications: Ideally, organisations create environments conducive to work engagement in which leadership plays an important role. This study found that one factor in the work environment, namely beneficiary contact, might have an adverse effect on the positive relationship that authentic leadership has on work engagement. Leaders should therefore take organisational contextual realities into account, such as regular, intense interaction of employees with the beneficiaries of their work. This situation could create strain for individual employees, requiring additional organisational support. Contribution/value-add: Organisations need to recognise the impact of beneficiary contact on the relationship between authentic leadership and work engagement. The researchers propose further studies on the influence of contextual variables on the relationship between leaders and followers.

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Beneficiary contact moderates relationship between authentic leadership and engagement

Orientation: Human resource practices influence the psychological contract between employee and employer and, ultimately, organisational performance. Research purpose: The objective of this study was to examine the effect of human resource practices on the types of psychological contracts in an iron ore mining company in South Africa empirically. Motivation for the study: Although there have been a number of conceptual studies on the effect of human resource practices on psychological contracts, there has been no effort to synthesise the links between these contracts and various human resource practices systematically. This study endeavoured to provide quantitative evidence to verify or refute conceptual studies on this relationship. Its findings could inform human resource strategies and, ultimately, the prioritisation of human resource practices to improve the cost-effective allocation of resources. Research design, approach and method: The researchers administered two questionnaires. These were Rousseau’s Psychological Contract Inventory (2000) and the Human Resource Practices Scale of Geringer, Colette and Milliman (2002). The researchers conducted the study with 936 knowledge workers at an iron ore mining company in South Africa. They achieved a 32% response rate. Main findings: The findings showed that most participants have relational contracts with the organisation. Another 22% have balanced contracts, 8% have transitional contracts whilst only 1% have transactional contracts. The study suggests that there are relationships between these psychological contracts and specific human resource practices. The study found that training and development was the most important human resource practice for developing relational and balanced contracts. Employees thought that they contributed more than their employer did to the relationship. The researchers developed a model to illustrate the influence of the various human resource practices on psychological contracts. Practical/managerial implications: The influence of human resource practices on relational contracts could assist organisations to invest in human resource practices. During recessions, organisations tend to reduce expenditure on human resource practices, especially training and development. The findings of this study, about the relationship between training and development and relational contracts, highlight the negative effect that this trend could have on psychological contracts, individual and organisational behaviour and, ultimately, organisational performance. Contribution/value-add: Based on this empirical study, the researchers proposed a conceptual model to illustrate the relationship between different psychological contracts and specific human resource practices, like training and development, which had the strongest relationships with relational contracts.

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The effect of human resource practices on psychological contracts at an iron ore mining company in South Africa

The purpose of this paper is to investigate the influence of a positive form of leadership, particularly authentic leadership, on ambidexterity, as ambidexterity has shown to improve financial performance. What is less clear, however, is how to create the organisational context towards ambidexterity or balanced exploitative and explorative innovation. This study set out to fill that gap in researching the direct influence of authentic leadership as well as indirect effect through innovation climate on ambidexterity.,A quantitative research approach was followed, with an online survey to employees in South African organisations. There were 733 useable questionnaires. Structural equation modelling was used to test proposed hypotheses of direct, indirect and moderation effects.,The results revealed that authentic leadership has a significant and positive direct effect on ambidexterity and a significant indirect effect through an innovation climate. Environmental dynamism lessened the regression weight of the relationship between authentic leadership and ambidexterity.,The data collected were cross-sectional and respondents were South African employees; therefore, caution should be exercised when generalising the results to other organisations in a broader African context.,Understanding that both authentic leadership and innovation climate are required to significantly influence ambidexterity allows organisations to direct their leadership selection and development.,The main contribution of this research lies in clarifying the influence of authentic leadership on ambidexterity in the South African context.

Authentic leadership’s influence on ambidexterity with mediators in the South African context

Orientation: Leadership styles influence knowledge workers’ job-stress-related presenteeism (JSRP) and, ultimately, organisational performance. Knowledge workers generally work under strict deadlines in fast-paced, stressful environments, and require organisational support. Research purpose: The objective of this study was to examine empirically the effect of three leadership styles, namely transformational, transactional and laissez-faire, on job-relatedstress presenteeism in knowledge workers across a number of industries in South Africa. Motivation for the study: Absenteeism has been the subject of much investigation but more research is required into the antecedents and consequences of presenteeism, the phenomenon of employees being physically present at work, but not fully functional and therefore unproductive. Illness as an antecedent to presenteeism has been studied, but limited attention has been given to presenteeism caused by stress. There are very few studies that investigate leadership styles as antecedents for JSRP and this study therefore sets out to provide quantitative evidence of this relationship. Research design, approach and method: The researchers used a cross-sectional quantitative approach within the positivism research philosophy. Two questionnaires were administered: the multifactor leadership questionnaire form 6S and the job-related-stress presenteeism questionnaire. Descriptive statistics and Pearson’s product-moment correlation were used to answer the research questions. The participants ( N = 242) were knowledge workers, representing 12 widely categorised industries. The researchers analysed job role descriptions to ensure the respondents were all knowledge workers. Main findings: Transformational leadership has a higher negative correlation with JSRP than does transactional leadership, whereas laissez-faire leadership has no significant relationship with job stress or JSRP. Practical/managerial implications: The research provides a compelling case for investment into transformational and transactional leadership development by showing the preventative effect that transformational leadership and, to a lesser degree, transactional leadership, has on stress-associated presenteeism. Contribution/value-add: Presenteeism lowers organisational performance even more than absenteeism does, and exists at huge cost to employees’ quality of work-life. This empirical study, the first to use valid, reliable questionnaires to investigate the relationship between transformational, transactional and laissez-faire leadership on the one hand, and JSRP on the other, suggests that transformational leadership development should be prioritised.

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An investigation into the effect of leadership style on stress-related presenteeism in South African knowledge workers

The purpose of this paper is to investigate the relationship between complexity leadership and contextual ambidexterity as well as the mediating effect of organisational innovation climate in this link. This study is an answer to a call on which leadership approach and mediating factors can meet today’s seemingly contradictory challenges of efficiently managing business demands, while simultaneously searching for new opportunities.,The researchers analysed 1,204 usable survey responses from employees of South African organisations. Analysis was in the form of structural equation modelling. Mediation analysis was carried out on estimates of the indirect effect.,Results show that complexity leadership was a strong predictor of innovation climate; in turn, innovation climate positively impacts exploratory innovation by 64 per cent; complexity leadership and innovation climate positively affect exploitation by 57 per cent. The innovation climate plays a total mediator role between complexity leadership and exploratory innovation and a partial effect on exploitation.,This study gives human resource management (HRM) insight into strategically directing leadership recruitment and development towards creating an organisational climate to enhance ambidexterity. HRM must conduct regular climate surveys to ascertain whether current leadership is creating an environment that enables exploratory and exploitative innovation.,The authors’ contribution includes a theoretical contribution to the emerging field of complexity leadership by offering conceptual as well as empirical evidence of its role in ambidexterity. This study extends previous research in highlighting organisational climate’s mediating role of being open to new ideas to enable exploratory innovation.

Caren Brenda Scheepers

Papers

Beneficiary contact moderates relationship between authentic leadership and engagement

The effect of human resource practices on psychological contracts at an iron ore mining company in South Africa

Authentic leadership’s influence on ambidexterity with mediators in the South African context

An investigation into the effect of leadership style on stress-related presenteeism in South African knowledge workers

Innovation climate mediating complexity leadership and ambidexterity