  Misinformation is an important topic in the Information Retrieval (IR)
context and has implications for both system-centered and user-centered IR.
While it has been established that the performance in discerning misinformation
is affected by a person's cognitive load, the variation in cognitive load in
judging the veracity of news is less understood. To understand the variation in
cognitive load imposed by reading news headlines related to COVID-19 claims,
within the context of a fact-checking system, we conducted a within-subject,
lab-based, quasi-experiment (N=40) with eye-tracking. Our results suggest that
examining true claims imposed a higher cognitive load on participants when news
headlines provided incorrect evidence for a claim and were inconsistent with
the person's prior beliefs. In contrast, checking false claims imposed a higher
cognitive load when the news headlines provided correct evidence for a claim
and were consistent with the participants' prior beliefs. However, changing
beliefs after examining a claim did not have a significant relationship with
cognitive load while reading the news headlines. The results illustrate that
reading news headlines related to true and false claims in the fact-checking
context impose different levels of cognitive load. Our findings suggest that
user engagement with tools for discerning misinformation needs to account for
the possible variation in the mental effort involved in different information
contexts.
