Figure 4.

Item information curves for the Lincoln Canine Anxiety Scale (LCAS). The x-axis measures the size of the latent trait (here the anxiety level) in arbitrary units. The Y–axis is the Item Information Function (IIF), indicating where an item is most informative w.r.t. the latent trait. The steepness and sharpness of the curve reflect the discriminating power of the respective item and thus the contribution the item makes to the precision of the measurement. Items with steeper curves are more useful.