Spatial visualization is a fundamental skill in technical graphics and engineering designs. From conventional multiview drawing to modern solid modeling using computer-aided design, visualization skills have always been essential for representing three-dimensional objects and assemblies. Researchers have developed various types of tests to measure students' spatial visualization abilities, in which most pictorial views of three-dimensional objects are represented by isometric views. Isometric views have many advantages such as being simple to draw, and equally representing the front, top, and side surfaces. However, they are also susceptible to drawing mistakes in spite of their relatively simple construction. This paper discusses the typical styles of visualization tests designed for engineering and technology students. Three formats for spatial visualization tests (developments, rotations, and isometric views) are discussed. A popular spatial visualization test is used as example to show some mistakes in its isometric views. Recommendations are made to improve pictorial views in spatial visualization tests. (Contains 3 tables and 13 figures.)