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Matthew H. Kramer, Ellen T. Paparozzi, and Walter W. Stroup

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

Matthew H. Kramer, Ellen T. Paparozzi, and Walter W. Stroup

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

Matthew H. Kramer, Ellen T. Paparozzi, and Walter W. Stroup

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

Free access

R. Daniel Lineberger

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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Michael S. McCoy, Kathleen M. Kelley, and Dan T. Stearns

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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Clifford M. Foust and Dale E. Marshall

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Arthur T. DeGaetano

Both mean temperature and daily temperature variance affect freeze risk in apples. Freeze damage to blossoms was assessed using a sequential model. In the model, once the chilling requirement was reached, growing degree days were accumulated and phenological stages determined based on growing degree thresholds derived from historical phenological observations. Critical temperatures for each stage were obtained from the literature and used to identify the occurrence freeze injury based on minimum temperature occurrence. In New York, temperature variance was the dominant climatological factor controlling freeze risk. A small <5% increase in variance counteracted mean temperature increases of up to 5.5 °C leading to increased freeze risk despite warming temperatures. In other apple-growing regions in the northwestern and southeastern United States, changes in freeze risk were dominated by changes in mean temperature. This demonstrates that in some regions the risk of freeze injury under future climate conditions may be more sensitive to changes in temperature variance. Variance is currently not well simulated by climate models. Because freeze risk also increases when the chill requirement is reduced, adaptation decisions to transition to lower chill requirement cultivars may be ill-advised in northern climates similar to New York as even the highest chill requirements were satisfied under the conditions with the greatest warming. This was not the case in other regions where the adoption of lower chill requirement cultivars may be warranted.

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Susan C. Miyasaka, Charles E. McCulloch, Graham E. Fogg, and James R. Hollyer

Taro (Colocasia esculenta L. Schott) is a root crop widely grown in the Tropics. To determine the optimum plot size for taro field trials, fresh and dry weights of individual corms were collected from two field trials conducted under flooded culture and two conducted under upland culture. For a given maximum test plot with a single border row surrounding inner measured plants, all possible combinations of smaller plot sizes were investigated. A plot size was defined as a given number of adjacent plants. A strong linear relationship was found between the natural logarithm of variance of yield and the natural logarithm of plot size. Expressed on the non-log-transformed scale, the point of maximum curvature in this relationship indicates a sudden decrease in advantage to larger plot sizes and is taken as optimum. Calculating maximum curvature mathematically, optimum plot size was 21 inner plants (5.7 m2) for the second flooded trial and 18 inner plants (4.9 m2) for the second upland trial. Another method of estimating optimum plot size minimized the cost per unit of research data by using the index of degree of correlation between neighboring plots. In three of four trials, the optimum plot size ranged from 16 to 24 inner plants (4.3 to 6.5 m2). In this second method, we calculated a non-linear relationship between plot size and outer border plants to estimate the fixed and per-unit cost of a single border row surrounding the inner measured plants. Both methods of calculating optimal plot size sometimes resulted in estimates that exceeded the maximum test plot size for particular field trials, indicating limitations of each method and the importance of managing field trials to ensure uniformity across treatments. No evidence of spatial autocorrelation was found in the corm yield of taro, indicating that the two methods used were adequate in calculating optimum plot size. In addition, we conducted an analysis based on statistical power but found that plot size did not materially affect the power to detect differences between treatments. To our knowledge, this is the first report of optimum plot size for field trials of taro.

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Richard P. Marini

Experiments with factorial arrangements of treatments plus one or more other treatment(s) are sometimes analyzed with a one-way analysis of variance (ANOVA) and means are separated with a multiple comparison. A set of single degree-of-freedom contrasts in a one-way ANOVA, provides formal tests for main effects and interactions. Data from a 2 × 3 factorial experiment that also contained a control were analyzed with a one-way ANOVA with a multiple comparison. Results from this analysis were compared to results obtained from a two-way ANOVA, a one-way ANOVA with pre-planned contrasts, a two-way ANOVA with least squares means comparisons obtained with SAS/general linear models procedure, and a regression model with an indicator variable and random blocks obtained with SAS/Mixed procedure. Results and interpretation differed depending on how the data were analyzed and these differences are discussed.