ABSTRACT
INTRODUCTION An important reason for undertaking an investigation into an area of research of relevance to dentists is the estimation of the value of a particular feature of a population. A question of this nature might be: “What proportion of 12-year-old girls have evidence of dental caries?” Although it might seem straightforward to calculate a proportion from a sample of girls, what is more diffi cult is to provide a range of believable values for the true proportion in the whole population. Statistical methods are required in order to give an indication of the accuracy of an estimate.
