It showed that trustees are generally able to explain their charity's aims and who benefits from their work. However, they are less successful in explaining how they have benefited in practice.
Plan UK director of comms Leigh Daynes said of the findings: 'The apparent deficit in describing the difference charities make is disappointing. Often charities bamboozle the public with jargon and faux management speak when they're sitting on a gold mine of human interest stories.'
The research assessed how registered charities are getting to grips with the requirement, introduced in 2008, to report on public benefit in their Trustees' Annual Report.
In its analysis of the research the Charity Commission notes that, overall, charity trustees have made progress with the new requirement.
Charities with incomes in excess of £500,000 were particularly successful, with 94 per cent partially or fully addressing public benefit. However, the research shows many smaller charities are still not meeting the regulations.
The research involved a review of 1,402 annual reports and discussions with 30 charities.
CharityComms director Vicky Browning said that charities needed to shift from a culture of measuring outputs to outcomes.
'Charities which take a comms-led approach to reporting impact are the ones who tend to be better at it,' she said. 'One of the key ways to demonstrate outcomes is through case studies.'