How External Auditors Evaluate Internal Audit Effectiveness: An Experimental Study of the Case of Jordan

The key focus of this study is to investigate external auditor (EA) perceptions regarding factors that affect the effectiveness of internal audit function (IAF). The study evaluates the influence of internal auditor objectivity, competence, and work performance on the effectiveness of the IAF in Jordanian listed companies (JLCs), as perceived by senior Jordanian EAs. The study employs a mixed method comprising a survey-based factorial experiment in addition to semi-structured interviews. The results, based on 35 completed surveys and nine interviews with senior EAs show that work performance has the greatest influence on the perceived effectiveness of IAF. However, all variables were found to be of substantial influence, and the differences in influence between the three independent variables are relatively minor. The analysis also revealed moderate to large statistically significant interactive effects between independent variables, suggesting that EAs use configural decision-making when evaluating the impact of the three dimensions. In interviews, EAs put forward many reasons for the importance of the three study variables, with no clear consensus on the reasons behind the rankings of the three independent variables. The narrow differences between the effects of the independent variables, in addition to a lack of clear explanations for these differences, suggest that situational factors may be involved (e.g., risk, organization complexity, resource availability, etc.). Our results have direct implications for efforts to improve the perceived effectiveness of the IAF. Professional and regulatory authorities charged with increasing the effectiveness of the IAF need to consider all three dimensions in their policy decision-making, given that all three dimensions have considerable direct and interactive effects.