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  • Verne Suarez posted an update 1 week, 4 days ago

    The index of agreement for models fit to subgroups of the data ranged from 0��79 to 0��97, indicating a high level of predictive power for all factor levels. Resampling of the full data set via bootstrapped samples of varying size indicated that the predictive power of model 3 was quite insensitive to variation in spatial replication, provided that all episodic predation intervals were represented in each of the resampled data sets. As the proportion of spatial replicates was varied from 1 to 0��05, EGFR inhibitor the bootstrapped value of d remained nearly constant, varying from 0��91 to 0��90 (Fig.?4). In contrast, reducing temporal sampling intensity substantially diminished the reliability of predictions of from episodic predation estimates. The index of agreement, d, varied as a function of temporal sampling intensity (d?=?0��042*ln(P(data))?+?0��90. As temporal sampling intensity P(data) dropped from 1 to 0��60 of the weekly episodic estimates, d declined from 0��91 to 0��88. When the proportion of temporal sampling fell below 0��60, d declined rapidly, falling to 0��83 when <25% of the data were sampled. The difference in sensitivity of the index of agreement for model 3, with respect to variation in spatial and temporal sampling intensity, was reflected in the spatial and temporal variances of seed predation at the Urbana, IL, USA location. Temporal variation was greater than spatial variation by more than a factor of seven (��2time?=?57��8, ��2space?=?7��5). For location 2, only models 1�C4 could be tested, because seed rain was not measured in Rostock. Model 3 (4?days seed exposure, with no scaling by seed rain) was the only member of this group of models that passed the first performance criterion, a KS test indicating that both predicted and observed values of were sampled from the same distribution (Table?2). Other goodness-of-fit criteria, including d, RMSE and mean bias error, were also superior for model 3 compared to the other three models. The observed and predicted values grouped diffusely about the 1:1 line (Fig.?5), as indicated by the regression between predicted and observed values (��0?=?0��11, ��1?=?0��96, R2?=?0��50, F1,26?=?26��0, P?<?0��001). When predictive models for were examined for goodness-of-fit to subgroups of the data (predator access: invertebrates only, invertebrates and vertebrates; subplot seed density), model 3 continued to be best supported by the data. The index of agreement for these models ranged from 0��73 to 0��93, indicating that model 3 resulted in robust estimates of for all factor levels. Model 3 performed best in subplots with the highest seed densities (5000 seeds per subplot; d?=?0��93), which were closest to the seed density on seed cards (10,500 seeds m?2). Bootstrapped predictions of by model 3 remained stable for a wide range of sample sizes.

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