An alternative randomized response model using two decks of cards


  • Sally Abdelfatah Cairo University
  • Reda Mazloum Cairo University
  • Sarjinder Singh Texas A&M University - Kingsville



In an attempt to obtain trustworthy answers from the respondents regarding a sensitive question in order to estimate the population proportion possessing that sensitive attribute, Odumade and Singh (2009) have suggested a randomized response model based on the use of two decks of cards. In this paper, a modification to the structure of the two decks of cards used by Odumade and Singh (2009) is proposed. The condition when the proposed model is more efficient than the Odumade and Singh (2009) model has been obtained. The proposed model can be easily adjusted to be more efficient than the Warner (1965), Mangat and Singh (1990), Mangat (1994) and Odumade and Singh (2009) models. Another advantage of the proposed model is that it can increase the respondents’ cooperation as they will be required to answer the sensitive question only once and not twice as in the case of the Odumade and Singh (2009) model.


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N. S. MANGAT, R. SINGH (1990), An alternative randomized response procedure, “Biometrika”, 77, pp. 439-442.

O. ODUMADE, S. SINGH (2009), Efficient use of two decks of cards in randomized response sampling, “Communication in Statistics-Theory and Methods”, 38, pp. 439-446.

S. L. WARNER (1965), Randomized response: a survey technique for eliminating evasive answer bias, “Journal of the American Statistical Association”, 60, pp. 63-69.




How to Cite

Abdelfatah, S., Mazloum, R., & Singh, S. (2011). An alternative randomized response model using two decks of cards. Statistica, 71(3), 381–390.