Representatives of people who were, as children, in residential institutions have expressed disappointment at decisions of the Investigations Committee of the Commission to Inquire into Child Abuse.
The committee chairman, Mr Justice Seán Ryan, yesterday said it had decided "not to name individual perpetrators of abuse unless they were convicted in the courts".
He also said he intended only "to call witnesses to give evidence of abuse suffered by them to the extent necessary for the inquiry".
Ms Christine Buckley, of the Aislinn centre in Dublin, said she was "shocked" and "very sad" the committee had decided to take the "sampling" route. She believed cost factors had superseded other issues.
Mr Mick Waters, of the SOCA (UK) group, representing survivors of child abuse, said he was very disappointed at what he considered a "massive change" where the committee was concerned.
Mr John Kelly, of Irish SOCA, said he was "extremely disappointed about the naming and shaming" but felt the committee had made it easier for the religious congregations to co-operate more fully with the investigation.
Mr Tony Treacy, of the Cork-based Right of Place group, said he was "sad that the committee does not appear to be listening to what survivors have been saying". As regards "sampling", Mr Treacy said "it would break my heart if I was not called to give evidence".
In a statement, the One in Four group said "the State made promises it could not keep, it assured each person of a hearing and a finding of fact in each case.
"Those involved, who were clearly failed in the past by the State, have good reason to believe that the State has once again failed them," the group said.
Mr Justice Ryan also said the committee planned to investigate the role of the courts in committing children to the institutions over the years.