Can the birth quantity be known one year earlier?]

In order to carry out the population control policy, efforts are needed to control pregancies and births. Studies show that 3 types of people may deliver babies next year: 1) those who are married at the end of the current year but have not become pregnant, 2) those who have 1 child at the present time and plan to have an additional child for special reasons, and 3) those who may get married during the 1st season of the coming year. Persons from the 1st 2 categories are easy to calculate or estimate. Persons from the 3rd category represent the core in predicting the birthrate for the coming year. Marriage ages and the distribution of dates for marriage are the 2 major sources of information for estimating the total number of persons who belong to the 3rd category. In the 1st step, we need to figure the ratio between the number of marriages in the 1st season and the total marriages for the whole year. Based upon available data for the past 3 years, a formula can be used to calculate this ratio. The marriage numbers for the 1st season of 1982 multiplied by the above percentage will be the possible number of marriages for 1982. Then, the possible number of births can be calculated by taking the birth ratio multiplied by possible marriages for 1982. Using the same method, the possible birth numbers for 1983 can be calculated. The above information shows that the total predicted births for 1983 includes 3 elements: 1) the number of those who aare married but not pregant and plan to give birth in 1983, 2) the number of those who received special permission to have a 2nd child in 1983, and 3) the number of those who may get married in 1982 and 1983 and who may give birth in 1983.     

Optimal estimation of a finite population mean under generalized random permutation models

Employing certain generalized random permutation models and a general class of linear estimators of a finite population mean, it is shown that many of the conventional estimators are “optimal” in the sense of minimum average mean square error. Simple proofs are provided by using a well-known theorem on UMV estimation. The results also cover certain simple response error situations.     

The Characteristics of Two Samples of Women Seeking Abortion in Queensland

The legalization of abortion is still a live issue in Queensland. The numbers and characteristics of women seeking abortion through the Children by Choice Association in 1973–74 and in 1980 were studied since no official statistics on abortion are available. From 1974 to 1980 there was a threefold growth in demand and a threefold rise in the proportion seeking their second or subsequent abortion. Both samples closely reflect the Queensland population as measured by place of birth and religious affiliation. Contraceptive knowledge was found to be associated with education while the proportion who stated they had formal lessons at school rose from 3% to 16% between the samples. In both samples two-thirds of the pregnancies resulted when no physical contraceptive was in use. Social characteristics of the women and men involved were investigated, as well as factors in the abortion decision.     

The Accuracy of Respondent-Coded Occupation

This study reports results from a methodological experimentconducted in a national survey to test the accuracy of respondent-codedoccupation. For most uses, we conclude that such measures aresufficiently precise. There are, however, some systematic sourcesof error which the investigator should be aware of.     

ON THE NONCENTRAL DISTRIBUTION OF A RANDOM MATRIX USEFUL IN CLASSIFICATION THEORY

To prove the optimality properties of the maximum likelihood (and also minimum distance) discriminant rule Rogers (1980, p. 98) embeds the maximum likelihood discriminant function in a Cauchy-Schwartz inequality. This embedding procedure of Rogers (1980) may be used to derive a new distribution for Anderson's (1958) classification statistic.     

An assessment of the quality of developmental day center playgrounds for exceptional children

This study assessed the playgrounds of developmental day care centers and compared them with playgrounds of regular certified day care centers. Twenty playgrounds, randomly selected from the listing of developmental day centers, were compared with a matched sample of 20 playgrounds from certified day care centers in one state. A revision of Frost's Playground Rating System (1978b) was employed to rate the two groups of playgrounds on content, safety, and function. Data were analyzed using an analysis of variance technique. The quality of developmental day center playgrounds for exceptional children was inferior to that of regular day care center playgrounds in terms of playground content. No significant differences were noted on safety or function.