haku: @indexterm POISSON DISTRIBUTION / yhteensä: 27
viite: 9 / 27
| Tekijä: | Duijn, M. A. J. van Böckenholt, U. |
| Otsikko: | Mixture models for the analysis of repeated count data |
| Lehti: | Applied Statistics
1995 : VOL. 44:4, p. 473-485 |
| Asiasana: | POISSON DISTRIBUTION ALGORITHMS |
| Kieli: | eng |
| Tiivistelmä: | Repeated count data showing overdispersion are commonly analysed by using a Poisson model with varying intensity parameter, resulting in a mixed model. A mixed model with a gamma distribution for the Poisson parameter does not adequately fit a data set on 721 children's spelling errors. An alternative approach is a step function. This gives a solution with many classes that is difficult to interpret. A combination of the two models, resulting in a mixture model with two gamma distributions, however, fits the data very well. Moreover, it yields a substantively satisfactory interpretation: two heterogenous classes of "good" and "poor" spelling children can be identified. |
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