Operation Span

Operation span (OSpan) was developed by Turner & Engle (1989) and remains the gold-standard complex working memory measure.

Unlike simple span tasks, OSpan forces simultaneous processing AND storage — the realistic working memory of everyday life.

You alternate solving math equations (true/false) with memorizing letters. At the end, recall the letters in order.

Scores predict reading comprehension, fluid reasoning, and academic performance.

Each test is constructed using Item Response Theory (IRT) and Classical Test Theory (CTT) to ensure reliable measurement of knowledge and ability across different difficulty levels.

Questions undergo rigorous review including difficulty calibration, discrimination analysis, and distractor effectiveness evaluation to maintain high assessment quality.

1. Each round shows a math equation — say True or False fast.
2. Then a single letter flashes — memorize it.
3. After all letters in the round, type them back in order.
4. The next round adds one letter. Two consecutive failures end the session.