Serial Reasoning (NNAT3 Level B)
Serial Reasoning presents a sequence of figures that changes in a rule-governed way. You choose the figure that comes next or fills a blank in the sequence. Level B sequences are short and use visible features such as shape, size, color, number, and position.
Core rules
- Look for one change at a time: size, color, number, position, rotation, or shape type.
- Decide whether the change is progressive (grows by one side each time), repeating (A-B-A-B), or alternating (two rules taking turns).
- Check the step size: does the figure rotate 90 degrees each time, or 45? Does the number increase by one or two?
- Confirm the rule against every figure in the sequence, not just the last two.
Worked example
Sequence: a triangle, a square, a pentagon, then a blank. The number of sides increases by one each time: 3, 4, 5. The next figure must have 6 sides, a hexagon. If the answer choices include a hexagon rotated differently, orientation does not matter unless the sequence also rotates. Here the shapes stay upright, so choose the upright hexagon. A circle is wrong because it has no sides and breaks the counting rule.
Traps
- Assuming the sequence repeats when it is actually growing.
- Skipping a step and choosing the figure two steps ahead.
- Missing a second feature that changes at a different rate.
- Choosing a figure that matches only the last figure, not the rule.