Even where the focus was on more systematic elements of HR eg employee involvement, the exclusion of other elements affecting performance such as training, appraisal or compensation may leag to rather narrow conclusions. It is also not always clear when an HR policy or practice becomes a system or a bundle (eg Bosalie and Dietz,2003). For example, training and development might be considered a single practice but may be expressed through management development, internal labour markets, succession planning processes, or traning. These kinds of practices have also appeared as a develpoment bundle. Some researchers have focused on related concepts such as a high involvment system (Lawler et al' 1995) or a high commitment system (Wood and Albanese,1995). There is also an absence of consensus over which aspects of firm performance it is that work practices are proposed to affect (Den Hartog and Verburg,2004), with measures ranging from financial peformance, productivity, employee commitment, absenteeism and customer satisfaction. Some studies have looked at hard data, other have focused on managerial preceptions of performance.