Control Balanced Designs Involving Sequences of Treatments

Designs involving sequences of treatments for test vs. control comparisons are suitable for research in which each experimental unit receives treatments over time in order to compare several test treatments to one (or more) control treatment(s). These designs can be advantageously used in screening experiments and bioequivalence trials. Three series of such designs are constructed in incomplete sequences wherein the first class of designs is variance balanced while the other two classes of designs are partially variance balanced for test versus test comparisons of both direct and residual effects of treatments

Neighbor Balanced Block Designs for Two Factors

The concept of Neighbor Balanced Block (NBB) designs is defined for the experimental situation where the treatments are combinations of levels of two factors and only one of the factors exhibits a neighbor effect. Methods of constructing complete NBB designs for two factors in a plot that is strongly neighbor balanced for one factor are obtained. These designs are variance balanced for estimating the direct effects of contrasts pertaining to combinations of levels of both the factors. An incomplete NBB design for two factors is also presented and is found to be partially variance balanced with three associate classes

Multifactor Experiments

Multifactor experiments investigate the impact of two or more factors or input parameters on a process' output response. Factorial experiment design, or simply factorial design, is a systematic approach for articulating the procedures required to successfully run a factorial experiment. Estimating the effects of numerous parameters on a process' output with a small number of observations is crucial for process output optimization

Resolvable mating-environmental designs for partial triallel cross experiments

Triallel crosses can be readily exploited as breeding tool for developing commercial hybrids with traits of genetical and commercial importance by acquiring information on specific combining ability effects along with general combining ability effects if the experimentation size is reduced to an economical extent. In this paper, methods of constructing designs involving partial triallel crosses in smaller blocks using different types of lattice designs have been introduced. The designs have low degree of fractionation, which suggests their utility when there is a resource crunch. Canonical efficiency factor of these designs relative to an orthogonal design with same number of lines, assuming constant error variance for both situations, is high indicating that adoption of these designs for the trials could bring about improvement as the recommendations from the experiment will be associated with a high precision

Neighbour Balanced Designs for Diallel Cross Experiments

This paper deals with obtaining series of block designs for complete and partial diallel cross experiments balanced for neighbour effects. Two series of Neighbour Balanced Block (NBB) designs for diallel cross in complete blocks and two series of NBB for diallel cross in incomplete blocks have been obtained. A catalogue of designs for number of lines ≤ 20 has been prepared listing the parameters of the designs

Designs for sensory trials involving foods of animal origin

Sensory quality is a basic factor that influences consumers while purchasing processed food of animal origin. Experimental designs will prove an effective tool in establishing a sensory fact in trials involving animal produce. To draw valid conclusion from a study, it is important to eliminate or minimize all sources of error and control all factors that may influence the inference. Hence, in addition to the potential sources associated with the preparation of the test products, variability due to measurement or assessment process, order effects, carryover effects and assessor fatigue are to be considered. When there are a large number of products, two operational constraints limit the choice of experimental designs viz., assessor constraint that sets a maximum number of products that an assessor can evaluate within a session before onset of sensory fatigue and preparation constraint that limits the number of products that can be prepared for a given session without loss of experimental control. Hence, it is many times necessary to split sensory evaluation into two sessions. Here, a general method to construct designs for sensory trials in two sessions, which are balanced for carry over effects within session, is proposed. The design is resolvable in the sense that panelist would get an opportunity to evaluate every product exactly once at the end of both the sessions

Web based Generation of Polycross Designs (webPD)

Careful choice of parental lines and efficient mating designs form the backbone to a successful plant breeding programme. Objectives of the study, nature of genotypes, pollination type, space, cost, heterogeneity present in the field, wind direction, etc. are some of the deciding factors of a mating design. For wind pollinated species, a group of selected genotypes are to be arranged in isolated blocks/rows and columns such that each genotype gets an equal chance of pollinating, or being pollinated by, any of the others. Different types of designs for polycross trials are conducted for different situations like octa neighbour balanced polycross designs, designs for directional wind system, neighbour restricted polycross designs, etc. For ready referencing and potential use of these designs, online software for generation of these designs is highly desirable. In this paper, the development of a web solution for generation of different classes of polycross designs based on client–server architecture has been discussed. The software webPD is easily accessible at any time from any arbitrary platform throughout the globe through the use of internet. This software provides freely available solution for the researchers, breeders and students working in this area

IBM SPSS Statistics: An overview

Statistical Package for the Social Sciences (SPSS), is a comprehensive system for data analysis. The SPSS package includes a number of software programs for data entry, management, statistical analysis, and presentation. SPSS combines complex data and file administration with statistical analysis and reporting tasks. SPSS can produce tabular reports, charts and maps of distributions and trends, descriptive statistics, and sophisticated statistical analyses. IBM® SPSS® Statistics is a potent statistical software platform. It provides a user-friendly interface and a comprehensive set of capabilities that enable to swiftly get useful insights from your data. High accuracy and high-quality decision-making are supported by sophisticated statistical techniques. The whole analytics lifecycle—from data preparation and management to analysis and reporting—is covere

Third Order Response Surface Designs for Sequential Experimentation

Response surface methodology is being widely used in developing and improving the quality characteristics of process/product through response surface model based optimization. Second order rotatable designs (SORDs) are the most prominent and popular class of designs used for such optimization trials. When the response obtained from a second order rotatable design (SORDs) is modelled using a second order model, it may sometimes lead to significant lack of fit which indicate the inadequacy of the model. Then one may think of a third order model to establish a functional relationship between the response and the input variables. Experimenting with a new third order rotatable designs (TORDs) in such a situation would be expensive as the responses observed from the first stage runs would be kept underutilized. In this paper, construction of TORDs suitable for sequential experimentation has been discussed which allows the estimation of parameters of the second order model at first stage and further fitting of third order model with addition of few more design points

t-designs involving treatment combinations for animal experimentation

Small and marginal farmers in India prefer an Integrated Farming System (IFS) approach i.e. a mixture of crop and livestock that enables them to maintain a stable income throughout the year. Identifying the best location-specific t-component crop-livestock combination to generate maximum profit is the major concern. t-designs can play a vital role in bringing out those best combinations. However, in many situations, combinations derived from specific components may not be practically feasible in a certain locality. Partially balanced t-designs with few selected combinations may prove to be useful in such situations. t-designs are special type of partially balanced incomplete block (PBIB) designs with some additional properties. Here, two series of partially balanced t-designs with some interesting characterization properties have been obtained by using the triangular association scheme. These designs find high application potential in crop and animal experimentation, especially in IFS research involving both crop and livestock components