# Psychological Sciences Faculty

## Ehtibar Dzhafarov

Professor, Mathematical and Computational Cognitive Science

**Mailing Address:**

Department of Psychological Sciences

Purdue University

703 Third Street

West Lafayette, IN 47907-2081 USA

**Campus Address:
**Peirce Hall, Room 365D

**E-mail:** ehtibar@psych.purdue.edu

**Website:** http://www2.psych.purdue.edu/~ehtibar/

**Degree:** Ph.D. Moscow (Lomonosov) State University, Russia, 1979, Mathematical, Cognitive

### Research Interests:

Mathematical theory of subjective dissimilarities among perceived stimuli; fundamental properties and abstract models of perceptual discrimination; multidisciplinary theory of selective influences (which inputs influence which random outputs); mathematical theory of probabilistic context and its parallels with quantum physics.

### Recent Publications:

**Dzhafarov, E.N.** & Dzhafarov, D.D. (2010). Sorites without vagueness I: Classificatory sorites. *Theoria, 76*, 4-24.

**Dzhafarov, E.N.** & Dzhafarov, D.D. (2010). Sorites without vagueness II: Comparative sorites. *Theoria, 76*, 25-53.

**Dzhafarov, E.N.** (2010). Dissimilarity Cumulation as a procedure correcting for violations of triangle inequality. *Journal of Mathematical Psychology, 54*, 284-287.

**Dzhafarov, E.N.** (2010). Dissimilarity, quasidistance, distance. *Journal of Mathematical Psychology, 54*, 334-337.

**Dzhafarov, E.N.** & Perry, L. (2010). Matching by adjustment: if X matches Y, does Y match X?* Frontiers in Quantitative Psychology and Measurement. 1*:24. doi:10.3389/fpsyg.2010.00024

**Dzhafarov, E.N.** & Kujala, J.V. (2010). The Joint Distribution Criterion and the Distance Tests for selective probabilistic causality. *Frontiers in Quantitative Psychology and Measurement. 1*:151 doi: 10.3389/fpsyg.2010.00151.

Trendtel, M., Ünlü, A., and **Dzhafarov, E.N.** (2010). Matrices satisfying Regular Minimality. *Frontiers in Quantitative Psychology and Measuremen, 1*:211. doi:10.3389/fpsyg.2010.00211.

**Dzhafarov, E.N.** (2011). Mathematical foundations of Universal Fechnerian Scaling. In B. Berglund, G.B. Rossi, J. Townsend, & L. Pendrill (Eds). Measurements With Persons (pp. 185-210). New York: Psychology Press.

**Dzhafarov, E.N.** & Colonius, H. (2011). The Fechnerian idea. *American Journal of Psychology, 124*, 127-140.

**Dzhafarov, E.N.**, Ünlü, A., Trendtel, M., & Colonius, H. (2011). Matrices with a given number of violations of Regular Minimality. *Journal of Mathematical Psychology, 55*, 240–250.

**Dzhafarov, E.N.** (2011). On the reverse problem of Fechnerian Scaling. In E.N. Dzhafarov & L. Perry (Eds). Descriptive and Normative Approaches to Human Behavior (pp. 91-122). New Jersey: World Scientific.

Dzhafarov, D.D. &** Dzhafarov, E.N. **(2011). The equivalence of two ways of computing distances from dissimilarities for arbitrary sets of stimuli. *Journal of Mathematical Psychology, 55*, 469-472.

**Dzhafarov, E.N.** & Kujala, J.V. (2012). Selectivity in probabilistic causality: Where psychology runs into quantum physics. *Journal of Mathematical Psychology, 56*, 54-63.

**Dzhafarov, E.N.** & Dzhafarov, D.D. (2012). The sorites paradox: A behavioral approach. In L. Rudolph (Ed). Qualitative Mathematics for the Social Sciences: Mathematical Models for Research on Cultural Dynamics (pp. 105-136). London: Routledge.

**Dzhafarov, E.N.** & Kujala, J.V. (in press as of 2011). Order-distance and other metric-like functions on jointly distributed random variables. Proceedings of the American Mathematical Society.

**Dzhafarov, E.N.** & Kujala, J.V. (2012). Selectivity in probabilistic causality: Where psychology runs into quantum physics. *Journal of Mathematical Psychology, 56*, 54-63. (available as arXiv: 1110.2388.)

**Dzhafarov, E.N.** & Dzhafarov, D.D. (2012). The sorites paradox: A behavioral approach. In L. Rudolph (Ed). Qualitative Mathematics for the Social Sciences: Mathematical Models for Research on Cultural Dynamics (pp. 105-136). London: Routledge.

Colonius, H. &** Dzhafarov, E.N.** (2012). Ultrametric Fechnerian Scaling of discrete object sets. In M. Deza, M. Petitjean, & K. Markov (Eds.) *Mathematics of** Distances and Applications* (pp. 129-132). ITHEA: Sofia.

**Dzhafarov, E.N.** & Kujala, J.V. (2012). Quantum entanglement and the issue of selective influences in psychology: An overview. Lecture Notes in Computer Science 7620, 184-195. (available as arXiv:1209.0041.)

**Dzhafarov, E.N.**, & Kujala, J.V. (2013). Beyond quantum probability: Another formalism shared by quantum physics and psychology. A commentary on “Can Quantum Probability Provide a New Direction for Cognitive Modeling?” by E.M. Pothos and J.R. Busemeyer. Behavioral and Brain Sciences, 36, 283-284.

**Dzhafarov, E.N.** & Kujala, J.V. (2013). All-possible-couplings approach to measuring probabilistic context. PLoS ONE 8(5): e61712. doi:10.1371/journal.pone.0061712. (available as arXiv:1209.3430.)

**Dzhafarov, E.N. **& Kujala, J.V. (2013). Order-distance and other metric-like functions on jointly distributed random variables. Proceedings of the American Mathematical Society, 141, 3291-3301. (available as arXiv:1110.1228.)

**Dzhafarov, E.N.**, & Kujala, J.V. (2014). Selective influences, marginal selectivity, and Bell/CHSH inequalities. *Topics in Cognitive Science *6, 121-128 (available as arXiv:1211.2342.)

**Dzhafarov, E.N.**(2014). Unfalsifiability and mutual translatability of major modeling schemes for choice reaction time.

*Psychological Review*121, 1-32.

Jones, M., & **Dzhafarov, E.N.** (2014). Analyzability, ad hoc restrictions, and excessive flexibility of evidenceaccumulation models: Reply to two critical commentaries. *Psychological Review *121, 689-695.

**Dzhafarov, E.N.**, & Kujala, J.V. (2014). No-Forcing and No-Matching theorems for classical probability applied to quantum mechanics. *Foundations of Physics *44, 248-265 (available as arXiv:1305.3649.)

**Dzhafarov, E.N.**, & Kujala, J.V. (2014). Embedding quantum into classical: contextualization vs conditionalization. *PLoS One *9(3): e92818. doi:10.1371/journal.pone.0092818 (available as arXiv:1312.0097.)

**Dzhafarov, E.N.**, & Kujala, J.V. (2014). A qualified Kolmogorovian account of probabilistic contextuality. *Lecture Notes in Computer Science *8369, 201-212 (available as arXiv:1304.4546.)

**Dzhafarov, E.N.**, & Busemeyer, J.R. (2014). Quantum models for psychological measurements: An unsolved problem.

*PLoS ONE*9(10): e110909. doi:10.1371/journal.pone.0110909 (available as arXiv:1403.3654.)

**Dzhafarov, E.N**__.__, & Perry, L. (2014). Perceptual matching and sorites: Experimental study of an ancient Greek paradox. *Attention, Perception, and Psychophysics *76, 2441-2464.

**Dzhafarov, E.N.**, & Kujala, J.V. (2014). Contextuality is about identity of random variables. *Physica Scripta *T163, 014009 (available as arXiv:1405.2116.