Using web-based tools for teaching statistical concepts and experimentation skills
This paper describes a number of generally accessible web-based tools the authors developed over the last couple of years and used in several statistics courses, ranging from the introductory statistics course to a specialized design of experiments course. The first set of tools (VESTAC) illustrates statistical concepts, the second one (VIRTEX) consists of virtual experiments. We discuss some of our experiences with regard to the development and maintenance of these tools and their use in ex cathedra teaching sessions, in guided practice sessions and in student projects. Finally we discuss a third type of tools: distance experiments.
A dynamic tomato growth and yield model (TOMGRO)
ABSTRACT Models of the greenhouse environment and of crops are needed to determine optimal strategies for environment control in regions where new greenhouse industries are developing. In this research, a physiological model of tomato crop development and yield was developed. A series of differential equations represent the changes in numbers and weights of leaves, fruit, and stem segments and in the areas of leaves, as new organs are initiated, age, and senesce or are picked. The model uses a source-sink approach for partitioning carbohydrate into growth of different organs. An experiment was conducted in six outdoor, controlled environment, growth chambers to quantify the effects of temperature, CO2, and light on tomato growth processes for calibrating the model. The model accurately described the differences in growth and yield of tomatoes that were observed in the experiment. With additional testing, the model can be used to help determine strategic and tactical decisions concerning greenhouse environment control over practical ranges of CO2 and temperature.
Designing a First Experiment: A Project for Design of Experiment Courses
Abstract A project suitable for use as a first and last assignment given in an introductory experimental design course is outlined, and its implementation discussed. Phase 1 of the project is designed to be given at the beginning of a first course in experimental design and involves designing an experiment within instructor-specified parameters based initially on intuition and common sense. Phase 2, at the conclusion of the course, represents the final assignment of the course and encourages the student to critique their first design, suggest a “new and improved” design based on their newly acquired knowledge, and finally conduct an analysis of computer generated data (here using MINITAB, although choice of package is flexible) from an actual run of their experiment.