This is often not the case; where the value of Fitts' Index of Difficulty is low, it is likely that movements will be made ballistically.
Figures 1, 2, 3 and 4 present type I error rate of the four DIF methods across different levels of person and item clustering effects, impact, testlet and DIF contamination when the studied item's difficulty is low.
Figures 5, 6, 7 and 8 present MSE of the four DIF methods across different levels of person and item clustering effects, impact, testlet and DIF contamination when the studied item's difficulty is low.
The multilevel testlet model perform the best when the item difficulty is low and medium with small average bias (−0.02 and −0.04), and perform the worst when the item difficulty is high with large average bias (0.92), which can be explained by the sparse cells due to high difficulty, resulting in extreme solutions.
If the score of the escape difficulty is low, we can suspect that the node lies in a sparse and highly connected neighborhood (formally, in a part of the graph with good expansion), such as a tree, or a forest, rather than a collection of weakly connected clusters.
Mean patient difficulty was low (M = .95, SD = .74, on a scale ranging from 0 to 6).
When there was impact between groups, the multilevel testlet model was most accurate in terms of estimating DIF parameter among the four methods when the studied item's difficulty parameter was low or medium, but was the least efficient method due to its complexity.
Consistent with the stated hypothesis, participants reported the lowest satisfaction ratings when tasks were perceived as highly difficult and highly important and were most satisfied when difficulty ratings were low and the tasks were rated as high on importance.
The percentage of subjects avoiding foods because of difficulties with chewing was low (<5 %) except for carrots (12 %) and nuts (10%%).
As can be seen in Fig. 2a, there was a significant effect of labeled difficulty for the blocks that were low in actual difficulty, where performance was superior during "HARD -labeled blocks, t(19) = 2.17, p =.043 (two-tailed).
