Is reliability compromised towards the end of long personality inventories?

During very long self-rating sessions there is a risk that respondents will be tired and/or lose interest. Is this a concern for users of long personality inventories, such that the reliability becomes threatened in the latter half when respondents have made hundreds of personality self-ratings? Two thousand three hundred and fifty two volunteers completed long (≈ 500 items) personality inventories on the Internet, where items were presented in a unique random order for each participant. Perhaps counterintuitively, there was no evidence that reliability is threatened as respondents approach the end of a long personality inventory. If anything, the ratings in the second half of the inventories had higher reliability than ratings in the first half. Ratings were quicker towards the end of the inventories, but equally reliable. The criterion validity, estimated using Paunonen’s Behavior Report Form, was maintained too. The current results provide little reason to mistrust responses to items that appear towards the end of long personality inventories.