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The incorrect use of statistics in scientific articles seems to be a never-ending discussion topic. A current controversy involves a decision by Basic and Applied Social Psychology in 2015 to ban the use of P -values (i.e., null hypothesis

Open Access

The incorrect use of statistics in scientific articles seems to be a never-ending discussion topic. A current controversy involves a decision by Basic and Applied Social Psychology in 2015 to ban the use of P -values (i.e., null hypothesis

Open Access

The incorrect use of statistics in scientific articles seems to be a never-ending discussion topic. A current controversy involves a decision by Basic and Applied Social Psychology in 2015 to ban the use of P -values (i.e., null hypothesis

Open Access

The World Wide Web is regarded widely as an invaluable asset to teaching and extension programs. Data supporting this assertion can be gathered actively or passively and can be analyzed to aid decision makers in matters of personnel evaluation and resource allocation. Most Web server software applications keep a log of connections by time, location, and file size transferred. The server logs of Aggie Horticulture, the Web site of the Texas Horticulture program, are analyzed bi-weekly using WebStat 2.3.4 and the number of logins, file size transferred (total and amount per sub-site), and client domain are tabulated. The number of “hits” increased from 15,000 to 120,000 per month (mid-February to mid-March of 1995 and 1996, respectively) over the last year. The logins came from 61 Internet domains representing 56 different countries. The “net” and “com” domains exhibited the greatest increase. “Active” data acquisition through a guest register at one of the sub-sites indicated that only 9% of the visitors registered. However, the data obtained from the active registrants were useful in determining the distribution of users by state and county within Texas.

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and inferential statistics. Results and discussion General demographics. Five-hundred four usable questionnaires were received, resulting in a 10% response rate. A majority of respondents to the survey were male (63.3%) and of white/Anglo decent (88

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Abstract

Horticulturalists frequently use the analysis of variance (F-test) to determine treatment differences. Many simple non-parametric tests, which require fewer assumptions, are also available. This note presents an example of the modified Friedman test as an alternative analysis for ranked data from a randomized complete-block design.

Open Access

Abstract

Experimental results from horticultural field trials are obscured by the effect of systematic variation. This variation is directly related to the position of the plot in the field and is referred to as a fertility gradient(s). Trend analysis eliminates the effect of fertility gradients by fitting a polynomial regression equation (response surface model) to the systematic variability in the experimental units. Two cultivar trials of potato (Solanum tuberosum L.) conducted to compare results from trend analysis with that using the standard design analysis indicated that fertility gradients existed in the fields and were of a form that could be adequately fitted by a response surface model. A 3-dimensional plot of the response surface model indicated that the fertility gradients formed a very complex surface which could not be eliminated by experimental design. Of the 3 experimental designs used, the Latin square was the most efficient while the completely random was the least efficient. Trend analysis resulted in a large gain in relative efficiency over the standard analyses of completely random and randomized block designs. It also resulted in a substantial gain over that of a Latin square design. Adjusting the means using a response surface model in trend analysis also improved treatment estimates. Tests of significance using adjusted means were more precise and easier to interpret. Trend analysis proved to be the most efficient way to analyze the data, regardless of the experimental design used.

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Abstract

Blocking of experimental units is frequently used to improve the precision of an experiment, yet many discussions of optimal plot size do not include a factor for the effect of blocking. Since there is a relationship between the choice of optimal plot size and number of plots per block, such an omission may make recommendations inappropriate for blocked experiments. An adjusting formula of H. F. Smith allowing for blocking is expressed more intuitively in terms of the correlation among plots within blocks.

Open Access

Abstract

Despite the fact several papers have been published concerning the use and misuse of multiple comparison methods (MCM), one can still find examples of their misuses in recent issues of HortScience and the Journal of the American Society for Horticultural Science. Three topics discussed below are: regression, multiple comparisons and contrasts, and factorial experiments.

Open Access