Time limits can change what aptitude test scores measure, according to an analysis of practice assessments by PrepClubs Research. The findings raise a question for employers using speeded tests as a screening threshold: how much of a candidate's result reflects reasoning and how much reflects pace?
The company analysed 727 re-graded practice attempts from 575 candidates across nine test formats. On 533 speeded attempts, 57.4% of questions in the final fifth of the paper were left unanswered, compared with 12.1% on 184 attempts with a more generous clock.
PrepClubs found that scores on speeded forms correlated more strongly with the share of the paper reached (r=0.72) than with accuracy on answered questions (r=0.56). The pattern reversed on generous-clock forms: the respective correlations were 0.59 and 0.77.
The published report summarises one finding this way:
“57.4% of the final fifth of the paper is never answered.”
The analysis covers voluntary practice tests written to published formats, not official employer assessments or scores used in job applications. PrepClubs excluded attempts that could not be reliably re-graded or showed too little evidence of a full sitting. Employers should therefore treat the results as a prompt to review test design and thresholds, rather than as proof of how their own candidates perform.
Source: PrepClubs Research, The State of Timed Assessment 2026, published 23 September 2026.
