RT Journal Article T1 The difference model with guessing explains interval bias in two-alternative forced- chocice detection procedures A1 García Pérez, Miguel Ángel A1 Alcalá Quintana, Rocío AB The standard difference model of two-alternative forced-choice (2AFC) tasks implies that performance should be the same when the target is presented in the first or the second interval. Empirical data often show “interval bias” in that percentage correct differs significantly when the signal is presented in the first or the second interval. We present an extension of the standard difference model that accounts for interval bias by incorporating an indifference zone around the null value of the decision variable. Analytical predictions are derived which reveal how interval bias may occur when data generated by the guessing model are analyzed as prescribed by the standard difference model. Parameter estimation methods and goodness-of-fit testing approaches for the guessing model are also developed and presented. A simulation study is included whose results show that the parameters of the guessing model can be estimated accurately. Finally, the guessing model is tested empirically in a 2AFC detection procedure in which guesses were explicitly recorded. The results support the guessing model and indicate that interval bias is not observed when guesses are separated out. PB Wiley SN 1745-459X YR 2010 FD 2010 LK https://hdl.handle.net/20.500.14352/44909 UL https://hdl.handle.net/20.500.14352/44909 LA eng NO Ministerio de Educación y Ciencia (España) NO Ministerio de Ciencia e Innovación (España) DS Docta Complutense RD 29 abr 2024