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Usability is one of the main and core concepts for fulfilling the quality requirements of any software product, particularly web-based systems. A widely used method to measure the level of usability of software applications is heuristic evaluation (HE). In this method, experts commonly use Nielsen’s heuristics to assess the usability of a software product. However, it can also be used by non-experts. Although experts yield better outcomes than non-experts, the former are difficult to obtain and recruit, unlike the latter. In order to improve the effectiveness of heuristic evaluation, several studies have sought to develop its heuristics and procedures. However, there are few studies that involve the end-user within this method, and to the best of our knowledge there are no studies involving end-users with non-expert evaluators within heuristic evaluation method procedures. Therefore, the aim of this study is to investigate the impact of end-users on non-expert evaluator results within the heuristic evaluation process, and through that, to explore the number of usability problems and their severity. The research proposed two sessions: a user exploration session (UES-HE) and a user review session (URS-HE). The former session aims to help the non-expert evaluator to understand the end-user, while the latter session tries to help the non-expert evaluator to review his results through communication with the end-user. One group took part in each session and the outcomes were compared with the traditional HE method as a benchmark. The outcomes show that the end-user has a significant impact on non-expert evaluator results in both sessions through the number and type of usability problems discovered. In the UES-HE method, the results outperformed both URS-HE and HE in terms of usability problems discovered, and it tended to find more major, minor and cosmetic problems than the URS-HE and HE methods. In the URS-HE method, the results outperformed HE but not UES-HE, and tended to find more major problem problems than the HE method. Key Words: Usability, Inspection Usability, Heuristic Evaluation, Non-expert Evaluator, User Session.