tools to assist in generating actor maps). The exercise is essential for ensuring that information is sought in a systematic and methodologically consistent manner. The challenge is to create and maintain such tools within the constraints (mostly time and resources) that affect all investigations. Information frequently arrives in inconsistent ways: a small piece from one interviewee who is reliable; a large portion of detailed information from another who is less so, and so on. Open-source information can make a significant contribution in this respect, but its credibility must be scrutinized, as with all sources. Actor maps help manage this diversity of source material. Investigations generally begin by canvassing available information from reliable open sources, and proceed by filling in missing pieces as the investigation progresses. Mapping actors and entities is no different: publicly available information on potential perpetrators is recorded and updated as further information is gathered. Good practice is to include ratings on the credibility of the information and the reliability of the source, in order to assess the level of confidence in each such identification. Example 1: Sri Lanka 2015 In its public report the OHCHR Investigation on Sri Lanka (OISL) set out the Sri Lankan military and security structures involved in hostilities during the latter periods of the conflict. Over 27 paragraphs described in detail – in some cases using organization charts – their functions, leadership (including names) and manner of involvement. Much of that information was gathered from publicly available sources: Task Force: “This was an ad-hoc grouping put together for a specific task requiring a separate formation command. It was hierarchically equivalent to a division, but had the size of a strong brigade. It comprised a mixture of existing units “borrowed” from other formations and new units that were raised by new recruitment during the rapid expansion of the army. According to maps compiled by the Defence Ministry, Task Forces 2, 3, 4 and 8 were particularly involved in the final weeks of the conflict. According to the Ministry of Defence website, the following were Commanders of Task Forces: Brigadier Rohana Bandara (Task Force 2); Brigadier Sathyapriya Liyanage (Task Force 3); Colonel Nishantha Wanniarachchi (Task Force 4); Colonel G.V. Ravipriya (Task Force 8).”88 A/HRC/30/CRP.2, 2015, para. 119 (emphasis added). 88 COLLECTING AND ANALYSING THE INFORMATION 47