The phrase "are unable to evaluate" is correct and usable in written English.
You can use it when discussing a lack of capability or capacity to assess or judge something.
Example: "Due to the lack of data, we are unable to evaluate the effectiveness of the new policy."
Alternatives: "cannot assess" or "are not in a position to evaluate."
Many of these buildings remain in service as part of critical lifeline facilities, but engineers are unable to evaluate their seismic performance by modern evaluation methods.
Those behind the bill say minors need to be protected from "homosexual propaganda" because they are unable to evaluate the information critically.
Although we are all a bit narcissistic, especially as children, it becomes a disorder when you get stuck in fixed patterns of behaviour and are unable to evaluate situations realistically or respond appropriately.
It means complainants are unable to evaluate the facts that determine findings, inhibiting complainants' ability to contest these facts and take further informed actions, such as filing civil suits.
"[Without financial education] consumers are unable to evaluate the appropriateness of financial products in relation to personal circumstances; they are exposed to predatory lending, pyramid schemes, financial scams and high penalty fees.
"Google's power in my view comes not from its large market share, but from the fact that consumers are unable to evaluate the product," said Mark R. Patterson, a law professor at Fordham who focuses on antitrust law.
But I would be unable to evaluate the actual x-ray data itself and decide if it's convincing or even legitimate.
Therefore, it was unable to evaluate quantitatively the coating protective performance by an electrochemical impedance method.
Fourth, due to modeling constraints we were unable to evaluate interaction effects of social support quality and quantity, further research is needed.
Due to a variety of factors to affect the herb quality, the existing quality management model is unable to evaluate the process control.
This study was unable to evaluate the efficacy of traditional health maintenance or protective behaviors for PUs, such as weight shifts or skin checks.
