Abstract: Evaluating and comparing the quality of surface interpolants is an important problem in computer graphics, computer aided geometric design and scientific visualization. Geometric uncertainty is a measure of interpolation error, level of confidence or quality of an interpolant that depends upon geometric characteristics of interpolants such as position, normals, isophotes, principal curvatures and directions, and mean and Gaussian curvatures. We present several new techniques for visualizing geometric uncertainty of surface interpolants, that combine the strengths of traditional techniques such as pseudo-coloring, differencing, overlay, and transparency with new glyph and texture-based techniques. The viewer can control an interactive querydriven toolbox to create a wide variety of graphics that allow probing of geometric information in useful and convenient ways. We demonstrate the effectiveness of these techniques by visualizing geometric uncertainty of surfaces obtained by different interpolation techniques bilinear, C⁰ linear, C² bicubic B-spline, multiquadrics, inverse multiquadrics and thin plate splines.