The concurrent think-aloud protocol—in which participants verbalize their thoughts when performing tasks—is a widely employed approach in usability testing. Despite its value, analyzing think-aloud sessions can be onerous because it often entails assessing all of a user's verbalizations. This has motivated previous research on developing categories to segment verbalizations into manageable units of analysis. However, the way in which a category might relate to usability problems is currently unclear. In this research, we sought to address this gap in our understanding. We also studied how speech features might relate to usability problems. Through two studies, this research demonstrates that certain patterns of verbalizations are more telling of usability problems than others and that these patterns are robust to different types of test products (i.e., physical devices and digital systems), access to different types of information (i.e., video and audio modality), and the presence or absence of a visualization of verbalizations. The implication is that the verbalization and speech patterns can potentially reduce the time and effort required for analysis by enabling evaluators to focus more on the important aspects of a user's verbalizations. The patterns could also potentially be used to inform the design of systems to automatically detect when in the recorded think-aloud sessions users experience problems.

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Soil erosion is one of the most serious environment problems in China. Soil and water conservation (SWC) measures play an important role in reducing streamflow and sediment yields. A nested watershed approach, together with the Mann–Kendall trend test, double mass curve, and path analysis were used to quantitatively explore hydrological effects of SWC measures in the Tingjiang River Watershed. Results showed the annual streamflow and sediment yields tended toward a remarkable downward trend since the implementation of SWC measures during 1982–2014, indicating that SWC measures produced significant hydrological effects. The contribution of precipitation to annual streamflow increased from 71% to 79% from the periods 1982–2000 to 2000–2014, indicating decreases in annual precipitation after 2003 and stronger impacts on streamflow than that of SWC measures. However, the contribution of SWC measures to sediment yields increased from 11% to 64% from 1982 to 2014 and gradually dominated contributions to the sediment yields in the watershed. An ecological threshold was established at which the proportion of the cumulative afforestation area due to SWC reaches 10% of the whole watershed, and the remarkable improvements of hydrological effects in the watershed can be observed. These findings could be used to evaluate performance of SWC measures in watersheds.

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