[3] On its database page the IBC states: "Gaps in recording and reporting suggest that even our highest totals to date may be missing many civilian deaths from violence.

According to Jonathan Steele, writing in The Guardian, IBC "is widely considered as the most reliable database of Iraqi civilian deaths".

[5] The IBC overview page states: "This is an ongoing human security project which maintains and updates the world's only independent and comprehensive public database of media-reported civilian deaths in Iraq that have resulted from the 2003 military intervention by the USA and its allies.

It also includes excess civilian deaths caused by criminal action resulting from the breakdown in law and order which followed the coalition invasion.

[6][7] The IBC overview page states: "Deaths in the database are derived from a comprehensive survey of commercial media and NGO-based reports, along with official records that have been released into the public sphere.

Reports range from specific, incident based accounts to figures from hospitals, morgues, and other documentary data-gathering agencies.

IBC defines civilian to exclude Iraqi soldiers, insurgents, suicide bombers or any others directly engaged in war-related violence.

as insufficient because it typically does not list the original sources for the information: that is, the NGO, journalist or government responsible for the number presented.

The IBC overview page states that its sources include "public domain newsgathering agencies with web access".

"[1] Civilian deaths in the Iraq war (cumulative): The figures above are those that appeared in real time on the IBC counters on or around those dates.

That page also says: "Gaps in recording and reporting suggest that even our highest totals to date may be missing many civilian deaths from violence.

The first paper, published in the New England Journal of Medicine in April, 2009, analyses civilian deaths between 2003 and 2008 according to weapon types used.

Among the findings were that, "execution after abduction or capture was the single most common form of death overall," and that, "events involving air attacks and mortar fire were the most dangerous" to Iraqi females and children.

[17] The second paper, published in PLoS Medicine in February, 2011, analyses civilian deaths between 2003 and 2008 according to perpetrator, weapon, time, and location.

The study found that unknown perpetrators firing mortars had the highest DWI ratio, followed by Coalition Forces air attacks, leading the authors to advise that such weapons should not be used in populated areas.

"[20] Others, often on the political left, criticized media and government willingness to quote IBC figures more approvingly than the much higher estimate coming from the Lancet study[21] that came out in October 2004.

That day, the Los Angeles Times and the Chicago Tribune each dedicated only about 400 words to the study and placed the articles inside their front sections, on Pages A4 and A11, respectively.

These biases and inadequacies, they claim, mean IBC's count is low by up to a factor of 10, and that it specifically minimizes the proportion of deaths caused by US forces.

[25] It stated: "Of course, in conditions of active rebellion, the safer areas accessible to Western reporters are likely to be those under US/Coalition control, where deaths are, in turn, likely to be due to insurgent attacks.

Areas of insurgent control, which are likely to be subject to US and Iraqi government attack, for example most of Anbar province, are simply off-limits to these reporters.

In a 28 April 2006 BBC Newsnight interview[28] the IBC project's co-founder John Sloboda, in response to these and similar arguments, has said: "we have never had over the entire three years, anyone show us an Arabic source that reports deaths that we haven't already got.

[29] The IBC acknowledges on its website that its count is bound to be low due to limitations in reporting stating; "many if not most civilian casualties will go unreported by the media.

"As a result, this technique of totaling up the dead is incapable of accounting for the deaths that were not being recorded, whether by the English-language news media or the chaotic health care system."

[30] The October 2006 Lancet study states: "Aside from Bosnia, we can find no conflict situation where passive surveillance recorded more than 20% of the deaths measured by population-based methods.

"[31][32] In an April 2006 article the IBC had described an example comparing itself to the 2004 United Nations Development Programme Iraq Living Conditions Survey (ILCS).

The 2006 Lancet study[31] also states: "In several outbreaks, disease and death recorded by facility-based methods underestimated events by a factor of ten or more when compared with population-based estimates.

The Lancet reference used is to Patrick Ball, Paul Kobrak, and Herbert F. Spirer and their 1999 book, State Violence in Guatemala, 1960-1996: A Quantitative Reflection.

Chapter 10[36] elaborates, saying that "In the CIIDH project, participating popular organizations collected many of the testimonies long after the time of the killings, when people were less clear about details, especially the identities of all the victims."

They report in chapter 7:[37] Figure 7.1 shows that in the CIIDH database, most of the information for human rights violations prior to 1977 comes from press sources.

In a 7 November 2004 press release[39] concerning the October 2004 Lancet study[21] the IBC states: "We have always been quite explicit that our own total is certain to be an underestimate of the true position, because of gaps in reporting or recording".