A more rational way to test a person's suitability would be to consult their years of existing performance reviews and evaluations with the department, she said, rather than take to a "pseudo-scientific" test.
"We're concerned that psychometric testing is being used as a kind of Trojan horse to make whatever unilateral and arbitrary staffing decisions that senior managers want," Polaczuk said.
The Inland Revenue says it sought an urgent hearing in the Employment Court when it received notice of legal proceedings from the PSA.
Mark Daldorf, chief people officer at the IRD said the department was undergoing a major redesign of its organisation and as part of it there would be a significant number of new roles that would be different to those people were currently performing.
"We are currently going through a selection process for around 860 of these positions, many of which are new specialist roles."
As part of that process it was using a broad range of information about staff to ensure it had the right people in the roles.
"Included in this are psychometric assessments, which help demonstrate a person's suitability for a new position."
Daldorf said people could choose to complete the assessment as part of the selection process.
"Inland Revenue uses these types of assessments in recruitment processes, and for existing employees as part of staff development. "
A date for the Employment Court hearing had yet to be scheduled but in the meantime its transition processes were continuing as planned.
Daldorf said he had no further comments at this time as the matter was before the court.
- with AAP