Serial Reasoning
Serial Reasoning presents a sequence of three to five figures and asks you to choose the next figure. NNAT3 Level D uses these items to test whether you can detect a progression and extrapolate it. The sequence may change one attribute at a time or run two rules in parallel, so you need to inspect each feature separately.
Rules to test
- Position: a shape may move one cell or corner per frame, clockwise or counterclockwise.
- Orientation: a shape may rotate by a constant angle, such as 45° or 90° per frame.
- Number: dots, lines, or sides may increase or decrease by a fixed step.
- Shading: black, gray, and white may cycle or alternate.
- Structure: the sequence may alternate between two shapes, or two independent sequences may be interleaved.
Worked example
A black dot moves clockwise around the four corners of a square, one corner per frame. A short line inside the square alternates horizontal, vertical, horizontal, vertical. Frame 1: dot at top-left, line horizontal. Frame 2: dot at top-right, line vertical. Frame 3: dot at bottom-right, line horizontal. Frame 4: dot at bottom-left, line vertical. The next frame returns the dot to top-left and the line to horizontal. A distractor with the dot at top-left but a vertical line satisfies the position rule and fails the alternation.
Traps
- Assuming a single rule when two attributes change independently.
- Continuing a rotation in the wrong direction because you checked only the last two frames.
- Missing an alternating pattern that resets every second or third frame.
- Choosing the option that repeats the last frame instead of advancing the sequence.
- Ignoring a count that changes by a constant amount but not by one.
Verify your rule against every given frame before selecting the next one.