  The visualization community regards visualization literacy as a necessary
skill. Yet, despite the recent increase in research into visualization literacy
by the education and visualization communities, we lack practical and
time-effective instruments for the widespread measurements of people's
comprehension and interpretation of visual designs. We present Mini-VLAT, a
brief but practical visualization literacy test. The Mini-VLAT is a 12-item
short form of the 53-item Visualization Literacy Assessment Test (VLAT). The
Mini-VLAT is reliable (coefficient omega = 0.72) and strongly correlates with
the VLAT. Five visualization experts validated the Mini-VLAT items, yielding an
average content validity ratio (CVR) of 0.6. We further validate Mini-VLAT by
demonstrating a strong positive correlation between study participants'
Mini-VLAT scores and their aptitude for learning an unfamiliar visualization
using a Parallel Coordinate Plot test. Overall, the Mini-VLAT items showed a
similar pattern of validity and reliability as the 53-item VLAT. The results
show that Mini-VLAT is a psychometrically sound and practical short measure of
visualization literacy.
