The phrase "assessing the truthfulness" is correct and usable in written English.
You can use it when discussing the evaluation or examination of someone's honesty or the accuracy of a statement.
Example: "The investigator was tasked with assessing the truthfulness of the witness's testimony during the trial."
Alternatives: "evaluating the honesty" or "determining the accuracy".
The Times is aggressive this year in assessing the truthfulness of the candidates' statements and ads, often putting it in an adversarial position with them.
Human rights investigators have developed methods for assessing the truthfulness of digital evidence, methods widely and openly shared within the human rights community.
Howard Kahane, a philosopher who sought to rid logic of its strict mathematical connotations, making it instead a tool for assessing the truthfulness of anything, including political statements, advertisements and school textbooks, died on May 2 in Mill Valley, Calif.
Assessing the truthfulness of such inflammatory statements — made by people who deserted the church or were expelled — was a challenge for the newspaper, which has maintained a special focus on Scientology.
The public has an interest in assessing the truthfulness of allegations of official misconduct, the newspaper said in its filing.
Be careful about assessing the truthfulness of someone's statement based on eye movements alone.
Still more ironically, the truth-squad techniques of recent journalism, in which TV reporters assess the truthfulness of negative ads, is probably backfiring.
During the interview process, which took two-and-a-half hours in its entirety, Mr Mullins also asks Mitchell a series of "comparison" questions to help him assess the truthfulness of his responses to the three key questions.
To assess the truthfulness of these values, we checked whether they were recorded simultaneously by Swarm A and C, and we found that these values were seen by both satellites.
The fact that one of the researchers (AMH) has participated throughout the planning process in all meetings, and has had access to most documents - electronic as well as paper-based - has made it possible to assess the truthfulness of, e.g. time pressure and the amount of documents related to the process.
