The chart below shows that conducting more inspections at the same observed SQG achievement rate (86%) results in a narrower confidence interval.

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Note: The above chart presents data collected from 57 facilities. The observed achievement rate is 86%.

Finally as illustrated by the chart that follows, the wide confidence intervals at performance rates of around 50% may not pose a problem for a state decision maker even at low numbers of inspections. The upper bound of the observed SQG achievement rate for RI’s indicator 11a is around 74% at a 90% confidence level. Even with as few as 16 inspections, the data may be precise enough for the decision maker to determine that compliance is not “good enough.”

## 95%

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Note: The above chart presents data collected from 16 facilities. The observed achievement rate is 56.3%.

Conclusion: In sum, while more inspections can help increase the precision and certainty of results, in many instances a state decision maker can still glean useful information at relatively low numbers of inspections, by looking at the confidence intervals at different confidence levels. See Appendix K for the confidence intervals for each state’s observed SQG achievement rates and mean facility scores at the 85%, 90%, and 95% levels. See Appendix L for the statistically significant differences in each state’s SQG achievement rates and mean facility scores at 85%, 90%, and 95% confidence levels.

# The States Common Measures Project Final Report

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