50 resultados para common method variance

em Deakin Research Online - Australia


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This paper presents a meta-analysis-based technique to estimate the effect of common method variance on the validity of individual theories. The technique explains between-study variance in observed correlations as a function of the susceptibility to common method variance of the methods employed in individual studies. The technique extends to mono-method studies the concept of method variability underpinning the classic multitrait-multimethod technique. The application of the technique is demonstrated by analyzing the effect of common method variance on the observed correlations between perceived usefulness and usage in the technology acceptance model literature. Implications of the technique and the findings for future research are discussed.

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Despite concern about method variance between measures as a bias in survey research, scholars have overlooked or ignored the effects of method variance within measures (i.e., covariation among items from the same scale that may be attributed to the method of measurement employed). Not only do few commonly used survey instruments reflect efforts to control for method variance, but guides to scale construction encourage researchers to implement strategies that enhance the effects of method variance within measures. In this article, we have argued that when method variance inflates relationships between questionnaire items, traditional psychometric indices overestimate the amount of true or construct variance that scales capture. Implications for survey research that uses fixed alternative questionnaire measures are delineated.

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Despite oxygen being one of the most frequently administered substances in the hospital environment, there is little empirical data regarding its use. Review of the literature regarding the clinical assessment of hypoxia and hypoxaemia reveals inconsistency in the definition of terms and raises questions as to the reliability of the clinical indicators currently used to assess the need for supplemental oxygen. Assessment of the need for supplemental oxygen and continued re-evaluation of the patient's oxygen requirements is a nursing responsibility. Physical assessment, in combination with pulse oximetry, is the most common method used by nurses to assess oxygenation status. This paper critically appraises the literature to examine the reliability of clinical indicators of oxygenation used by nurses in acute care settings.

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Flowcharting is a common method of setting out the requirements for a piece of code. It is simple with few rules to follow. Rarely however, is it used as the code itself. This paper describes the outline of a software package that uses the flowchart as the code for a small, autonomous, modular robot, designed for use in High Schools and Universities at an introductory level. By using flowcharting the student is introduced to the concept of structured programming. A flowchart is often the first step in programming. Here it is the only step, easing the student into the art of coding, and simplifying the teachers job.

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Flowcharting is a common method of setting out the requirements for a piece of code. It is simple with few rules to follow. Rarely however, s it used as the code itself. This paper describes the outline of a software package that uses the flowchart as the code for a small, autonomous, modular robot, designed for use in High Schools. It also describe the code used by the robot to complement the flowchart software creating a system that can be used by students and their teachers to design, build and program a robot without previous programming experience.

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A retrospective assessment of exposure to benzene was carried out for a nested case control study of lympho-haematopoietic cancers, including leukaemia, in the Australian petroleum industry. Each job or task in the industry was assigned a Base Estimate (BE) of exposure derived from task-based personal exposure assessments carried out by the company occupational hygienists. The BEs corresponded to the estimated arithmetic mean exposure to benzene for each job or task and were used in a deterministic algorithm to estimate the exposure of subjects in the study. Nearly all of the data sets underlying the BEs were found to contain some values below the limit of detection (LOD) of the sampling and analytical methods and some were very heavily censored; up to 95% of the data were below the LOD in some data sets. It was necessary, therefore, to use a method of calculating the arithmetic mean exposures that took into account the censored data. Three different methods were employed in an attempt to select the most appropriate method for the particular data in the study. A common method is to replace the missing (censored) values with half the detection limit. This method has been recommended for data sets where much of the data are below the limit of detection or where the data are highly skewed; with a geometric standard deviation of 3 or more. Another method, involving replacing the censored data with the limit of detection divided by the square root of 2, has been recommended when relatively few data are below the detection limit or where data are not highly skewed. A third method that was examined is Cohen's method. This involves mathematical extrapolation of the left-hand tail of the distribution, based on the distribution of the uncensored data, and calculation of the maximum likelihood estimate of the arithmetic mean. When these three methods were applied to the data in this study it was found that the first two simple methods give similar results in most cases. Cohen's method on the other hand, gave results that were generally, but not always, higher than simpler methods and in some cases gave extremely high and even implausible estimates of the mean. It appears that if the data deviate substantially from a simple log-normal distribution, particularly if high outliers are present, then Cohen's method produces erratic and unreliable estimates. After examining these results, and both the distributions and proportions of censored data, it was decided that the half limit of detection method was most suitable in this particular study.

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Rights issues remain a common method for raising equity capital in Australia for companies listed on me Australian Stock Exchange. This study investigates the capital raising costs of Anstralian renounceable equity rights issues from 2001 to 2006. Both direct and indirect costs are investigated and the explanatory power of potential influencing factors is analyzed. The total direct costs averaged nearly 4% of gross proceeds raised and the mean offer price was discounted around 17% from the current market price. Issue size, percentage underwritten, concentration of ownership and issuer risk significantly influence the percentage direct costs of the rights issue. The age of the issuer, the average historical volume of shares traded and the offer price appear to influence the percentage discount.

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The theory of reasoned action (TRA) specifies a set of expectancy-value, belief-based frameworks that underpin attitude (behavioural beliefs × outcome evaluations) and subjective norm (normative beliefs × motivation to comply). Unfortunately, the most common method for analysing these frameworks generates statistically uninterpretable findings, resulting in what has been termed the ‘expectancy-value muddle’. Recently, however, a dimensional salience approach was found to resolve this muddle for the belief-based framework underpinning attitude. An online survey of 262 participants was therefore conducted to determine whether the dimensional salience approach could also be applied to the belief-based framework underpinning subjective norm. Results revealed that motivations to comply were greater for salient, as opposed to non-salient, social referents. The belief-based framework underpinning subjective norm was therefore represented by evaluating normative belief ratings for salient social referents. This modified framework was found to predict subjective norm, although predictions were greater when participants were forced to select five salient social referents rather than being free to select any number of social referents. These findings validate the use of the dimensional salience approach for examining the belief-based frameworks underpinning subjective norm. As such, this approach provides a complete solution to addressing the expectancy-value muddle in the TRA.

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© Emerald Group Publishing Limited. Purpose – Although there is growing research on the relationship between ethical leadership and subordinate work behaviors, limited research has examined the boundary conditions under which ethical leadership is more or less effective. The purpose of this paper is to investigate whether subordinate perceptions of role clarity in their job role influence the relationship between ethical leadership and subordinate work behaviors. Drawing on both social exchange and social learning theories, the authors predict that in contexts where subordinates perceive low levels of role clarity, the relationship between ethical leadership behavior and subordinate helping and deviant behaviors will be weaker. Design/methodology/approach – In total, 239 employees in the Chinese public sector completed surveys across three separate time points. Confirmatory factor analysis and hierarchical regression analysis were used to analyze the data. Findings – Analyses provided support for the hypothesized relationships. When subordinates perceived higher levels of role clarity the positive relationship between ethical leadership and helping behavior was stronger, and the negative relationship between ethical leadership and deviant behavior was stronger. Research limitations/implications – As with all research the findings of this study need to be viewed in light of its limitations. First, the use of data from a single set of respondents opens up the possibility of common method bias. Second, given the study used of a sample of public sector employees from one part of China, there would be value in future research examining whether the findings from the present study are generalizable to other industrial and cultural contexts. Practical implications – This research has a number of practical implications. Given that the authors found a significant positive relationship between ethical leadership and helping behavior, and a significant negative relationship between ethical leadership and deviant behavior, it is crucial for organizations to include ethical training as an essential part of leadership development programs. However, the findings also suggest at the same time as facilitating the development of ethical leadership behaviors amongst supervisory employees, it is important for organizations to also provide employees with clarity over what is expected of them in their jobs, and the means they should employ to facilitate goal achievement. Originality/value – This study responds to recent calls for more research to identify factors which may strengthen or mitigate the influence of ethical leadership in the workplace.

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The machining process is the most common method for metal cutting, especially in the fabrication of biomaterials and artificial implants. In modern industry, the goal of production is to manufacture products at a low cost, with the highest quality in the shortest time. The main focus of the research presented here is to provide a review of the machinability of metallic and ceramic biomaterials in traditional machining processes, such as turning, milling and grinding. Thereafter, machining strategies, machinability and surface characteristics post machining are discussed. To provide a better understanding of the machining process, various cutting tools and fluids are analysed. Finally, the current research gap and directions of prospect investigations are highlighted.

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This paper proposes an innovative optimized parametric method for construction of prediction intervals (PIs) for uncertainty quantification. The mean-variance estimation (MVE) method employs two separate neural network (NN) models to estimate the mean and variance of targets. A new training method is developed in this study that adjusts parameters of NN models through minimization of a PI-based cost functions. A simulated annealing method is applied for minimization of the nonlinear non-differentiable cost function. The performance of the proposed method for PI construction is examined using monthly data sets taken from a wind farm in Australia. PIs for the wind farm power generation are constructed with five confidence levels between 50% and 90%. Demonstrated results indicate that valid PIs constructed using the optimized MVE method have a quality much better than the traditional MVE-based PIs.

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A statistical optimized technique for rapid development of reliable prediction intervals (PIs) is presented in this study. The mean-variance estimation (MVE) technique is employed here for quantification of uncertainties related with wind power predictions. In this method, two separate neural network models are used for estimation of wind power generation and its variance. A novel PI-based training algorithm is also presented to enhance the performance of the MVE method and improve the quality of PIs. For an in-depth analysis, comprehensive experiments are conducted with seasonal datasets taken from three geographically dispersed wind farms in Australia. Five confidence levels of PIs are between 50% and 90%. Obtained results show while both traditional and optimized PIs are hypothetically valid, the optimized PIs are much more informative than the traditional MVE PIs. The informativeness of these PIs paves the way for their application in trouble-free operation and smooth integration of wind farms into energy systems. © 2014 Elsevier Ltd. All rights reserved.

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Stock repurchases (or share buy-backs) have become increasingly popular among Australian companies. One of the main aims of announcing a stock repurchase by a listed company is signalling the market that its shares are currently underpriced. When market reacts to the signal, price of the shares is expected to increase immediately after the announcement. While there are several ways of repurchasing shares, 'on-market buy-backs' is the most popular method of stock repurchases in Australia. Australian listed companies have announced more than two hundred on-market share buy-backs over the past three years. The aim of this paper is to examine the information signalling effects of these on-market buy-back announcements. If the signal is considered positively (negatively) by the market, the price of the repurchasing company's shares should increase (decrease) immediately after the announcement. If there is no information content in the announcement, the price will remain the same. In this study, signalling effect of share buy-back announcements was examined using most recent Australian data. The total population of on-market buy-back announcements during the period from January 1, 2000 to March 10, 2003 was included. The abnormal market return over the short-run (announcement day and 9 trading days centred on the announcement date) was computed using the All Ordinaries Accumulation Index as the reference portfolio. The daily Abnormal Returns (AR) and Cumulative Abnormal Returns (CAR) during the event period were computed. The results strongly support the information-signalling hypothesis of share buy..backs. Australian market generally considers announcement of on~market share repurchases as signalling of insider information that shares are currently underpriced.

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A VHF method (30-300 MHz) is applied to identify faults and defects in ceramic insulators. Insulators which exhibit internal cracks and fractures are used as test samples. Different artificial conditions are introduced to the test samples according to the IEC 507 standard under wet and dry conditions. Using a cascading signal processing technique and analysis methods such as FFT and fractal analysis, VHF signals acquired by digital scope are processed and analyzed. This study indicates that the fractal dimension can be used as an effective tool to isolate the common faulty conditions found on the ceramic insulators. The results from this study strongly support the prospect of using a VHF method to monitor the physical condition of ceramic insulators.

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Four treatments including three different concentrations of pineapple solution (I %, 3%, 5%) and the traditional method (salt/urea/tannin solutions) were used to eliminate egg stickiness of common carp. With the traditional method, fertilization and hatching rates were 74.5% ± 1.2 and 70.2% ± 1.1, respectively. The highest fertilization rate (89.3% ± 0.7) and hatching rate (86.6% ± 1.4) were found with treatment of 1% pineapple juice solution and was significantly different from those obtained with other treatments (P<0.05). Using pineapple juice for desticking common carp eggs also reduced the time of egg handling from almost one hour required with the traditional method, to about three minutes, as well as increasing fertilization and hatching rate under hatchery conditions.