The publication of data as part of the Government's transparency agenda should be accessible and easily understood by all, a group of MPs has said.
Further work needs to be done in certain areas to "realise the full benefits of transparency", including service improvement, public accountability and economic growth objectives, the Commons Public Accounts Committee concluded.
In its report entitled "Implementing the transparency agenda", MPs raised concerns over gaps in giving relevant information and over the comparability of data where it was of poor quality.
As one example, it noted the price and performance information for adult social care was incomplete and could not be easily compared across local authority boundaries.
The committee also found that the presentation of much Government data was poor.
Committee chair Margaret Hodge said: "This committee fully supports the principle of greater openness and its potential to strengthen accountability and drive improvements in public services. But the Government has a lot more work to do before that potential is realised.
"It is simply not good enough to dump large quantities of raw data into the public domain. It must be accessible, relevant and easy for us all to understand.
"Otherwise, the public cannot use it to make comparisons and exercise choice, which is the key objective of the transparency agenda.
"At the moment too much data is poorly presented and difficult to interpret. In some sectors, such as adult social care, there are big gaps in the information provided so users cannot use it to make informed choices."
The report concluded that in some sectors different provider types were subject to different transparency requirements, undermining the comparability of data for users.
It also stated the Government "does not understand" the costs and benefits of its transparency agenda and "has not got a clear evidence-based policy" on whether or not to charge for data.
The committee also warned there was a risk that those without internet access would not gain the full benefits of more open public data.
Ms Hodge added: "As more and more different providers are involved in providing our public services, there must be a level playing field in terms of transparency.
"At the moment, individual academies do not make available information on spending per pupil that allows value for money to be compared fully between different types of school.
"One area of particular concern to this committee is that private providers can hide behind 'commercial confidentiality' to block the disclosure of relevant information. We must be able to follow the taxpayers' pound wherever it is spent.
"Data is also being issued by government and other public bodies without any clear idea of the costs, benefits and risks of doing so.
"The Government should develop a comprehensive analysis of what it actually costs to release data, and of the real benefits and risks.
"Those without access to the internet must not be forgotten. They are often the very people who rely most on public services and could benefit most from access to better information.
"Further steps to ensure universal access to public data should be developed and set out."
TaxPayers' Alliance chief executive Matthew Sinclair, who gave evidence to the committee's inquiry, said: "We have always
campaigned for greater openness and transparency in public data, which will allow taxpayers to hold politicians and bureaucrats to account for how their money is spent.
"The Government has made welcome progress making more information accessible but must not allow the momentum to falter.
"While we note the Public Accounts Committee's concern about how some of that data is presented, this must not be used as a reason for restricting the release of any data or for spending large sums in preparing it for publication.
"The overwhelming priority must be to release as much data as possible and then to allow civil society to innovate and show how it can be used best."
Cabinet Office Minister Francis Maude said: "This is the most transparent Government in British history and we are leading the world on this agenda. We thank the Committee for their support and will carefully review their report before responding.
"We agree that open data allows citizens to hold governments to account, drives improvements in public services by informing choice, and provides a feedstock for innovation and growth.
"We also agree that everyone should have access to open data - that's exactly why we set out last month how the Government will ensure open data is more accessible and more usable, including overhauling the data.gov.uk site."Suggest a correction