Bradford’s Law and the Literature of Agriculture

The Productivity of Geographical Authors: A Case Study From Nigeria

“…The resulting bibliograph conforms com pletely with the linear ideal of the Bradford-Zipf bibliograph without the characteristic 'droop' that has been reported by earlier investigators who analysed the productivity of periodicals, for example Groos 20 and Lawani. 21 Using the formula whose parameters have already been explained above we find that N= 351.Thatis, 351 individual authors would have been expected to contribute at least one entry during the seventy-year period analysed. From Fig.…”

“…The values of b for different values of n are shown in Table 2 not to be constant. But Lawani, 21 working on periodical literature data for tropical and sub-tropical agriculture, reported that the value of b varies even when dealing with data covering a period of only one year. Similar variability has also been reported for the periodical literatures of other subjects.…”

The Core Periodicals in Career and Technical Education

“…Historically, researchers have found support for the theory that within any academic discipline the majority of citations come from a few core journals (e.g., Bradford, 1934;Broadus, 1952;Davis, 2002;Goldman, 1979;Goldsmith, 1983;Hamelman & Mazze, 1972;Hardesty & Oltmanns, 1989;Lawani, 1973;Subramanyam & O'Pecko, 1979). This pattern, referred to as the 80/20 rule, predicts that 80 percent of citations come from 20 percent of the cited journals (Trueswell, 1969).…”

“…Studies have been conducted to identify the core periodicals in a variety of disciplines such as marketing (Goldman, 1979), agriculture (Lawani, 1973), environmental sciences (Subramanyam & O'Pecko, 1979), sociology (Broadus, 1952), finance (Hamelman & Mazze, 1972), psychology (Sylvia & Lesher, 1995), real estate (Redman, Manakyan, & Tanner, 1999), and women's studies (Marinko, 1998) to name a few. However, a comprehensive review of the literature failed to find any empiricallybased study producing a list of core periodicals in career and technical education.…”

Una revisión crítica de la Ley de Bradford

“…A pesar de que algunas experiencias empíricas parecen haber verificado la clásica aplicación de la ley de Bradford a algunas disciplinas tales como las ciencias de la computación (Kendall, 1960), geografía (Aiyepeku, 1977), bibliotecología (Bulick, 1978), y agricultura (Lawani, 1973), "el suceso alcanzado hasta ahora en la explicación y fundamento teórico de la ley de Bradford y fenóme-nos correlativos pueden ser evaluados como modestos" (Oluic-Vukovic, 1993). Sin embargo, es necesario apuntar que los autores citados anteriormente no controlaron la frecuencia de publicación ni el periodo de participación de las revistas estudiadas.…”