Presentation
Investigating Effects of Elemental Design Characteristics on NASA-TLX Ratings
DescriptionThe NASA Task Load Index (NASA‑TLX) is the most widely used subjective measure of mental workload, yet its implementation varies substantially across studies and even within NASA’s own official materials. Differences in anchor labels, tick patterns, and dimension descriptions may unintentionally influence rating behavior, threatening the tool’s validity and comparability. This study systematically evaluates how these design characteristics affect NASA‑TLX ratings and identifies which versions best align with objective task performance. Thirty‑two participants completed Multi‑Attribute Task Battery II (MATB‑II) scenarios of varying difficulty and provided workload ratings using eight scale designs representing the full factorial combination of official NASA‑TLX design discrepancies. Linear mixed‑effects models assessed the effects of design elements on each TLX dimension. Results show that subtle visual and textual design differences meaningfully alter rating distributions. These findings highlight the need for standardization in NASA‑TLX scale design and provide evidence‑based guidance for selecting rating formats that improve measurement validity in human factors research.
Event Type
Lecture
TimeThursday, October 22nd11:20am - 11:40am PDT
Location