safety management. The main investigation items are shown inTable 1.The participants include owners, construction safety managers,safety engineer and the field workers, from the department of con-struction safety in several famous construction contractors, fromthe construction industry in Wuhan City of Hubei Province. Theyare selected to evaluate the prototype system because these con-tractors are interested in construction risk & safety since they areoften engaged in large, complex and high risk construction pro-jects. In addition, these contractors have better IT automation leveland therefore are more capable of testing the prototype system andproviding feedback. During survey, the research team introducedthe main functions and features of the prototype system. The par-ticipants were then asked to complete the questionnaires and togive their questions and suggestions or issues they were concernedabout the prototype system.The questionnaire includes several items and for each item par-ticipants are requested to give their opinions by ranking theirdegree of agreement. A five level Likert-scale is used in the ques-tionnaire, which is, Strongly agree (SA) = 5, Agree (A) = 4, Neutral(N) = 3, Disagree (DA) = 2 and very disagree (VDA) = 1. The partici-pants were asked to explain any items which they ranked ‘‘Dis-agree” or ‘‘Very Disagree”. The participants were also asked togive their feedback about the prototype system.Total 60 copies of questionnaire were distributed, and 58 copieswere collected and 55 copies were valid for this research. Theresults of the investigation were summarised inTable 1.FromTable 1, the overall feedback is on the positive side, andthe mean score is all above 3.40, with exception of item 6.We also recognised that the vagueness of these ranks and thepossible difficulty to distinguish the difference among these ranks.However, from the results of the table, for each item, except ‘‘item6”, the total proportion of the rank ‘‘Very Agree” and ‘‘Agree” isgreater than ‘‘50%”, therefore, this can still verify the potential ben-efits. All the participants think that the proposed system wouldhelp in decision making for construction risk identification and riskprevention planning. The survey shows that the prototype systemcan indirectly improve the risk or safety management perfor-mance, via facilitating risk management consideration during con-struction process planning. Many participants think that many riskevents are caused mainly by unsafe working practices of fieldworkers. Even though the system may inform them what risksmay occur and how to prevent the risk events, it may be difficultfor the field workers to change their working style (way) andunsafe working practices. Nonetheless, they believe the proposedapproach would help improve safety on construction sites indi-rectly. This opinion of the participants coincides with the investi-gation results byTam et al. (2004), in which ‘‘lack of training”,‘‘reckless operations” and ‘‘poor safety awareness” are identifiedas the main factors affecting construction safety.It is found that almost all participants are very concerned oneparticular issue which is the availability and feasibility of thesystem on construction sites, as they are used to the paper-basedrisk checklist tool. This issue could be resolved via a tablet versionof the system. At the same time, many participants also suggestthat videos and pictures about the risks and safety accidentsshould be added to the prototype system. These visual learningaids would make a more direct and real impact on the learnersabout the risks and their consequences and improve the risk andsafety awareness. This suggestion will be added to the futuredevelopment of the prototype system.5.3. DiscussionIn the prototype system, users can select any 3D components ina BIM environment, and the related construction risk knowledgeand documents can be viewed. BIM models provide visual knowl-edge reuse environment, however, it may be difficult to be imple-mented successfully if the BIM models are not available. Currently,one limitation of the prototype is the deep reliance on the informa-tion describing the construction monitoring objects, provided byBIM project model, such as the construction method and activity.If the information in BIM is incomplete or inaccurate, the construc-tion risk knowledge recommended by the system may be affected.However, in practice many engineers are not familiar with BIMmodel and rule base development. Therefore, the knowledgeexperts need take part in the BIM model and knowledge modelling.Another limitation is the complexity of the semantic represen-tation of risk knowledge, which makes it difficult to maintain. Thesemantic annotation of the construction risk documents can beintroduced to solve this problem. In this case, the accuratenessand correctness of the semantic annotation in the documentsmay greatly affect the knowledge acquisition. As pointed outbefore, it is very crucial for the