under-represent

It says the figures "almost certainly" under-represent the number of cases.

Cholera Cases Likely to Increase in Haiti 2010

This may under-represent the left a bit, but I think that with the growth of weblogs our blogroll is going to under-represent everything at this point.

Water Privatization, Continued, Arnold Kling | EconLog | Library of Economics and Liberty 2009

And search marketers tend to over-represent larger advertisers and under-represent the many smaller businesses that use search as a marketing tool, so their reports are far from definitive.

Data Points on Google’s Growth - Bits Blog - NYTimes.com 2008

Academics who developed the 18-item questionnaire said the stigma of admitting some disabilities and that their children were helping look after them, meant that the census was always likely to under-represent the true figures.

700,000 children acting as carers, survey shows Rachel Williams 2010

And search marketers tend to over-represent larger advertisers and under-represent the many smaller businesses that use search as a marketing tool, so their reports are far from definitive.

Data Points on Google’s Growth - Bits Blog - NYTimes.com 2008

A new report seems to pop up every week, and the incidents that find their way into newspapers very likely under-represent the phenomenon.

Paul Helmke: Barack Obama: "I Am Not In Favor Of Concealed Weapons" 2009

| Reply | Permalink yes. and very important to keep in mind that polls under-represent undecided voters, pushing them into one column or the other by posing the obama or mccain question in terms of 'if the election were held today ...'

Top Obama Labor Supporter Warns Race Remains Volatile, Says Voters Lack Clear Sense Of Obama 2009

However, this estimate is known to under-represent many wetland types, and further data are required for some geographic regions.

Ecosystems and Human Well-being~ Wetlands and Water~ Key Messages 2008

However, these sources were known to under-represent many wetland types, and further data are required for some geographic regions.

Ecosystems and Human Well-being~ Wetlands and Water~ Summary for Decision-makers 2008

But there would be huge difficulties in this kind of "improvement"... quite apart from the fact that it would be impossible with today's imperfect knowledge of star distances and even star counts for the dimmer red-dwarfs except the very closest stars.... any such simulator would seriously under-represent dim stars.

32 Nearby Stars 2008