A chronotype label is a cutoff, not a biological fact
Chronotype questionnaires ask about preferred sleep and activity times and then sort people into groups such as morning, intermediate, and evening types. The sorting depends on where the cutoffs are placed and which questions are asked, so two tools can put the same person in different groups. None of the studies here directly compares two questionnaires head to head, which means the size of that shift is not measured in this evidence.
What the studies do show is that the label matters once it is assigned. In adolescents, morning preference was associated with better school performance [1]. In boxers, visual reaction time varied across the day depending on chronotype classification [2]. In children assessed remotely, chronotype and time of day interacted in their cognitive performance [3]. Each of these results is tied to the particular questionnaire used, so the pattern is real for that instrument but not automatically transferable to another.
The same person can look like a morning performer or an evening performer
When a group is mixed, the average hides opposing peaks. Rae and colleagues note that in a group of mixed chronotype, peak time-of-day performance of morning types and evening types falls at different hours, so pooling them flattens the curve [4]. That is the clearest illustration of why classification matters: the observed time-of-day pattern is a blend of subgroups, and the blend depends on how the questionnaire divides them.
Hill and Chtourou found that the relationship between mood state and cycling performance across the day was determined by chronotype [5]. In other words, the same test at the same hour produced different mood–performance links for different chronotype groups. This is consistent with the idea that chronotype is not a minor covariate but a variable that changes the shape of the daily performance curve.
Habitual training time and age shift the observed peak
Rae and colleagues also point out that habitual training time-of-day influences diurnal variation in sports performance [4]. An evening type who habitually trains in the morning may show a morning peak that reflects training habit rather than chronotype alone. This means a questionnaire-based classification can mislead if it is used without information about the person's usual schedule.
Age is another modifier. Chronotype shifts toward eveningness during adolescence [1], so the same questionnaire applied to younger and older adolescents will classify different proportions of each group as evening types. The performance pattern observed in a school setting therefore depends on the age range sampled as well as on the tool.
The evidence supports an interaction, not a specific correction factor
Across these studies, the consistent finding is an interaction: chronotype classification and time of day jointly shape performance [2][3][5]. That interaction is observed with single questionnaires in each case, so it is robust as a qualitative pattern. What is not established is how much the choice of questionnaire moves the classification boundary or the estimated peak hour.
For a reader trying to interpret a time-of-day performance result, the practical takeaway is to ask which questionnaire was used and whether the sample was mixed. A mixed sample analyzed without separating chronotypes can produce a flat or misleading daily curve [4], and a single-group result may not generalize to a different classification scheme. The direction of the effect is clear; the magnitude of the questionnaire effect remains unmeasured in this evidence.
Sources used in this answer
Young people's time-of-day preferences affect their school performance
Adolescents' morning time-of-day preference, measured with a single questionnaire, was associated with better school performance, and chronotype shifted toward eveningness with age.
The effect of time of day on visual reaction time performance in boxers: evaluation in terms of chronotype
Visual reaction time performance in boxers varied across the day depending on chronotype classification from a single questionnaire.
Chronotype, time of day, and children's cognitive performance in remote neuropsychological assessment
In children assessed remotely, chronotype measured by the Children Chronotype Questionnaire and time of day interacted to affect cognitive performance.
Factors to consider when assessing diurnal variation in sports performance: the influence of chronotype and habitual training time-of-day
Classifying participants by chronotype revealed different time-of-day performance peaks, and in a mixed-chronotype group the peak performance times of morning and evening types differed; habitual training time-of-day also influenced diurnal variation.
The effect of time of day and chronotype on the relationships between mood state and performance in a Wingate test
The relationship between mood state and Wingate cycling performance across times of day was determined by chronotype.