Qualitative data | Quantitative data | |
Main phase | 668 hours of observations. 94 recorded interviews. | Measurement plans for eight sites. Data from 37 measures were available for independent SPC analysis, 19 of which were included (data from 18 measures were not amenable to independent analysis). |
Extension phase | 194 hours of observations. 49 recorded interviews. | Measurement plans for six sites. Data from 30 measures were included in independent SPC analysis. |
Total | 862 hours of observations. 143 recorded interviews. | Data from 67 measures, 49 of which were included in independent SPC analysis. |
SPC, Statistical Process Control.