Ulrich Rolf, Vorberg Dirk
Department of Cognitive and Biological Psychology, Psychological Institute, University of Tübingen, Friedrichstr. 21, 72072 Tübingen, Germany.
Atten Percept Psychophys. 2009 Aug;71(6):1219-27. doi: 10.3758/APP.71.6.1219.
Discrimination performance is often assessed by measuring the difference limen (DL; or just noticeable difference) in a two-alternative forced choice (2AFC) task. Here, we show that the DL estimated from 2AFC percentage-correct data is likely to systematically under- or overestimate true discrimination performance if order effects are present. We show how pitfalls with the 2AFC task may be avoided and suggest a novel approach for analyzing 2AFC data.
辨别性能通常通过在二选一强制选择（2AFC）任务中测量差别阈限（DL；或刚好可察觉差异）来评估。在此，我们表明，如果存在顺序效应，从2AFC正确率数据估计出的DL可能会系统性地低估或高估真实的辨别性能。我们展示了如何避免2AFC任务中的陷阱，并提出了一种分析2AFC数据的新方法。
