Pattern Completion
Pattern Completion asks you to restore a design that has a piece missing. On NNAT3 Level E, the item shows a large geometric pattern with a blank region, and the answer choices are small patches. Only one patch continues every line, color, and spacing rule in the surrounding design.
Read the whole design first
Before looking at the options, name the pattern's structure. Is it a grid of repeating cells? A figure with one or more lines of symmetry? A shape that repeats after a rotation? A border that alternates two motifs? The missing patch must satisfy the same structure at its edges, not just look similar in isolation.
Match at the boundary
Trace each line that meets the blank. If a diagonal stripe enters the blank on the left, it must leave on the right at the same angle and width. If a row of dots is evenly spaced outside the blank, the spacing must continue inside it. Check color and shading as carefully as shape: a black diamond cannot replace a white diamond merely because the outline matches.
Worked example
A square design has four triangular quadrants made by its two diagonals. The upper-left, upper-right, and lower-left quadrants each contain one small black dot, placed the same distance from the center. The lower-right quadrant is blank. The completed design is built so that a 90° rotation maps it onto itself. The missing patch must therefore contain one black dot in the lower-right quadrant, at the same distance from the center as the other three. An option with the dot in the corner of the patch, or with a white dot, breaks the rotation rule.
Traps
- Choosing a patch that fits the blank's outline but reverses a color.
- Copying a neighboring quadrant without applying the rotation or reflection.
- Ignoring spacing: a dot that is too close to an edge looks plausible but breaks the rhythm.
- Treating a symmetrical design as if only one half mattered.