The shape persistence of a crop yield
probability density function (PDF) was studied by using
two variants of the Visual Impact Method (VIM) to elicit
subjective estimations by farmers. In one ...variant ten
weights were used to describe the PDF and in the other
variant the farmer chose the number of weights. Results
were compared directly and by means of Weibull
distributions fitting, with evidence being obtained in
favor of methodological persistence and the equivalence
of the two estimation methods.
The shape persistence of a crop yieldprobability density function (PDF) was studied by usingtwo variants of the Visual Impact Method (VIM) to elicitsubjective estimations by farmers. In one variant ...tenweights were used to describe the PDF and in the othervariant the farmer chose the number of weights. Resultswere compared directly and by means of Weibulldistributions fitting, with evidence being obtained infavor of methodological persistence and the equivalenceof the two estimation methods.
The aim of this research is to establish the persistence of annual crop yield point values subjective estimates, and the coherence and reliability of subjective crop yield probability density ...functions (PDF) elicited from a series of interviews carried out on a wide group of farmers, and then to determine whether they should be included or not in a decision support system (DSS). Three different elicitation techniques were used:
a) The Two Step PDF estimation method
b) Triangular distribution
c) Beta distribution
Although the results are noteworthy, further studies should be carried out to perfect the aforementioned techniques before crop yield PDF's are used in decision making processes.
The shape persistence of a crop yield probability density function (PDF) was studied by using two variants of the Visual Impact Method (VIM) to elicit subjective estimations by farmers. In one ...variant ten weights were used to describe the PDF and in the other variant the farmer chose the number of weights. Results were compared directly and by means of Weibull distributions fitting, with evidence being obtained in favor of methodological persistence and the equivalence of the two estimation methods.
The shape persistence of a crop yield probability density function (PDF) was studied by using two variants of the Visual Impact Method (VIM) to elicit subjective estimations by farmers. In one ...variant ten weights were used to describe the PDF and in the other variant the farmer chose the number of weights. Results were compared directly and by means of Weibull distributions fitting, with evidence being obtained in favor of methodological persistence and the equivalence of the two estimation methods.
To know the Spanish homes reasons of purchasing broiler meat a survey of 1,000 families, by means of a 13 question interview, was carried out during
2007. After processing the information it was ...concluded that Spanish families purchase food an average of 2.34 times/week, 95% of which do not exceed 100 € and, with the exception of more than 400 € purchases, in more
than 90% of which broiler meat accounts for more than 14% of the spent budget. Broiler meat is bought near home, in butcher’s shops or supermarkets, with purchases via telephone or the internet being marginal. The main declared benefits of consuming broiler meat
were the low fat content, being a healthy meat, and being proper in a healthy diet. Surprisingly, 72% of interviewees did not see any benefit in chicken meat or did not answer to that question, contrasting with the fact
that only 20% of interviewees admitted low price as a benefit. Most of the Spanish families do not feel influenced by the media and/or advertising campaigns, what would support the hypothesis that they purchase
broiler meat as a “shelter product”, due to its quality and price competitiveness.
To know the Spanish homes reasons of purchasing broiler meat a survey of 1,000 families, by means of a 13 question interview, was carried out during2007. After processing the information it was ...concluded that Spanish families purchase food an average of 2.34 times/week, 95% of which do not exceed 100 € and, with the exception of more than 400 € purchases, in morethan 90% of which broiler meat accounts for more than 14% of the spent budget. Broiler meat is bought near home, in butcher’s shops or supermarkets, with purchases via telephone or the internet being marginal. The main declared benefits of consuming broiler meatwere the low fat content, being a healthy meat, and being proper in a healthy diet. Surprisingly, 72% of interviewees did not see any benefit in chicken meat or did not answer to that question, contrasting with the factthat only 20% of interviewees admitted low price as a benefit. Most of the Spanish families do not feel influenced by the media and/or advertising campaigns, what would support the hypothesis that they purchasebroiler meat as a “shelter product”, due to its quality and price competitiveness.
The aim of this research is to establish the persistence of annual crop yield point values subjective estimates, and the coherence and reliability of subjective crop yield probability density ...functions (PDF) elicited from a series of interviews carried out on a wide group of farmers, and then to determine whether they should be included or not in a decision support system (DSS). Three different elicitation techniques were used: a) The Two Step PDF estimation method b) Triangular distribution c) Beta distribution Although the results are noteworthy, further studies should be carried out to perfect the aforementioned techniques before crop yield PDF's are used in decision making processes.
The aim of this research is to establish the persistence of annual crop yield point values subjective estimates, and the coherence and reliability of subjective crop yield probability density ...functions (PDF) elicited from a series of interviews carried out on a wide group of farmers, and then to determine whether they should be included or not in a decision support system (DSS). Three different elicitation techniques were used: a) The Two Step PDF estimation method b) Triangular distribution c) Beta distribution Although the results are noteworthy, further studies should be carried out to perfect the aforementioned techniques before crop yield PDF's are used in decision making processes.
En la literatura sobre determinacion subjetiva de funciones de densidad probabilidad de rendimientos de cultivos, se ha senalado que los agricultores tienden a percibir f.d.p. muy estrechas, un ...resultado que coincide con el senalado en ortros contextos experimentales. En este trabajo se ha constatdo que investigadores y expertos en produccion vegetal tienen tambien una probre percepcion de la forma de la f.d.p. Esta sesgo en la perception de la f.d.p. sera compartido por agricultores y expertos, estos ultimos con una buena formacion estadistica. Sun embardo ambos grupos realizan in trabajo diario exitoso que implica frecuentemente discriminar entre f.d.p. de rendimientos de cultivos...The literature on the subjective elicitation of crop yield probability density functions points out that farmers have a tendency to perceive very tight PDF, a result which concurs with findings found in other experimental contexts. This study demonstrates that both academic and research experts in plant production have poor perception of what pdf is really like . This bias is shared by farmers and experts alike, the latter with solid statistical background. However, both groups carry out their work every day successfully, despite the fact that it frequently involves the distinction between different crop yield PDF's.
