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t-designs represent a generalized class of balanced incomplete block designs in which the number of blocks in which any t treatments (t≥ 2) occur together is a constant. Like other families of incomplete block designs, t-designs find potential application in farming system research where the main concern would be to select the best combination out of a certain set of t-component farming systems for a specific agro-ecological zone. But in order to obtain t-balance we may require large number of blocks and replications. Partially balanced t-designs are introduced for experimental situations where it is not possible to get t-balanced designs. A series of partially balanced 3-designs are constructed using mutually orthogonal latin squares. These designs, though possess pair-wise balance, are not combinatorially balanced in terms of 3-tuples. They also satisfy the properties of 3-packing designs. The efficiency factor of these designs is quite high as v increases, the efficiency increases. [ABSTRACT FROM AUTHOR]

Designs involving sequences of treatments are advantageously used when observations are taken repeatedly from same experimental unit period after period as a new treatment is applied in each period. Hence, inclusion of residual effects into the model becomes the most important feature of such designs. Six popular classes of designs involving sequences of treatments are studied under a model with carryover effects proportional to the direct effects where the unknown proportionality parameter assumed values from -1 to +1. The objective of this empirical study was to determine the value of proportionality parameter for which maximum information can be drawn from the design. [ABSTRACT FROM AUTHOR]

Kronecker product of matrices can be advantageously used to obtain three-associate class partially balanced incomplete block (PBIB) designs from two-associate class PBIB designs, for a larger number of treatments. This method has been described here and two such series of PBIB designs are obtained. If the experimenter is constrained of resources, theses designs can be used as an alternative to balanced incomplete block designs or 2-associate class partially balanced incomplete block designs. [ABSTRACT FROM AUTHOR]

Evaluation of veterinary medicinal products is one of the important areas where bioequivalence trials are conducted. One of the problems commonly encountered in bioequivalence trials is outlying subjects. These outlying data may occur either as unexpected observations or as the unusual subject who has extremely high or low bioavailability with respect to the reference formulation and may have dramatic effects on the bioequivalence test. Therefore, it is important to examine the data carefully for identification of outlying observations in bioequivalence studies. In this study we have developed another general approach, termed the Estimated Distance (ED), to the outliers' detection problem. [ABSTRACT FROM AUTHOR]

In this paper, a new series of incomplete block designs with three replications has been proposed. These designs are partially variance balanced following a group divisible association scheme. The designs obtained here are with unequal block sizes and are suitable for experimentation in uneven land. Furthermore, these designs are resolvable, which enhances their application potential in regions where it may be difficult to accommodate complete replications at one place. [ABSTRACT FROM AUTHOR]

In this article, we have discussed some aspects of block designs under systematic trend component. The necessary and sufficient condition for a block design to be trend free has been highlighted. A method of constructing linear trend free block designs in two plots per block have been discussed. The characterization properties of such designs have been investigated. [ABSTRACT FROM AUTHOR]

Sensory trials are an integral part of food and nutrition experiments involving agricultural/ animal produce to demonstrate some sensory fact. To draw definite conclusion from the study, it is important to eliminate or minimize all sources of error, and recognize and control all factors that may influence or interfere with the result. In addition to various potential sources associated with the preparation of the test products, there may be variability due to measurement or assessment process, order effects, carryover effects, assessor fatigue etc. Sometimes, designs are required which can provide higher precision estimates for the crucial product comparisons, at the cost of the comparisons which are of lesser interest, and will be estimated with lower precision. One situation where there is special interest in a subset of product contrasts arises when control products are included in the trial. A control product provides a calibration standard, which can serve as a basis for comparison of results across studies may be helpful to the panel. Here, a series of treatment vs. control designs for multi-session trials are obtained to deal with such situations. [ABSTRACT FROM AUTHOR]

In any scientific experiments, heterogeneitymay present either in one direction or may be more than one directions. Designs under two source of heterogeneity is mainly used for such situations where there are evidences of two-source of heterogeneity. In this article, we have discussed some aspects of designs under two-source of heterogeneity along with examples of trend free designs for such situations. [ABSTRACT FROM AUTHOR]

Cross breeding is one of the major tools used by breeders for exploiting heterosis to develop useful commercial hybrids. Being most simple and easy to handle, diallel cross hybrids are the most commonly used hybridization method. But, triallel cross hybrids are genetically more stable and consistent in performance than diallel cross hybrids. Here, a method of constructing design for breeding trials involving complete/partial triallel crosses has been developed. This method is based on triangular association scheme. The variance of contrasts pertaining to estimated general combining ability (gca) effects of full parents as well as half parents are of two types in accordance with the association scheme used for its construction, indicating that this design is partially variance balanced. The efficiency factor in terms of information per cross pertaining to general combining ability effects of half parents as well as full parents in comparison to a complete triallel cross plan, assuming the error variance to be same for both the plans, has been computed and is found to be fairly high. The method has been illustrated through a proper example. [ABSTRACT FROM AUTHOR]

Generalized Row-coulmn (GRC) designs are used when the number of treatments is substantially large with limited number of replicates controlling heterogeneity in two directions. GRC design is an arrangement of 'v' treatments in 'p' rows and 'q' columns such that the intersection of each row and column consists of more than one unit. Here, some experimental situation along with an example for constructing GRC designs have been discussed. [ABSTRACT FROM AUTHOR]