Appendix 4: Summary Statistics, Outliers, and Confidence Intervals
Basic summary statistics from the questionnaire (Appendix 2) were compiled for dependent variables and closely related questions. These statistics include the mean, median, range, and standard deviation for all data points, less respondents from State Geological Surveys (SGS) and international venues, as well as statistically trimmed data. Outliers were trimmed by two methods resulting in distinct datasets that preserve the 5th-95th percentiles of values and values with a Z-score less than or equal to three standard deviations. Trimmed medians are omitted, as trimming resulted in an equal number of values removed from either end of data range, i.e., median values are not changed by outlier trimming. Finally, 95% confidence intervals were computed for the median, mean, and both trimmed means. The results of this analysis are shown in the below Tables A4.1, A4.2, and Figure A4.1.
Table A4.1: Summary statistics, outlier trimming, and confidence intervals calculated for variables: 5-year cost savings (Q3a), 5-year time savings (Q3c), self-developed map total project cost (Q7b), number of maps for project example (Q7c), willingness to pay (Q8), and willingness to pay certainty (Q9).
| Metric | 3a: 5-year Cost Savings (%) | 3c: 5-year Time Savings (%) | 7b: Self-developed Map Total Project Cost ($USD) | 7c: Number of Maps for Project Example | 8: Willingness to Pay ($USD, bin center) | 9: Q8 Certainty* |
|---|---|---|---|---|---|---|
| Mean | 5.860E+02 | 6.546E+01 | 6.417E+08 | 1.752E+01 | 3.157E+04 | 5.902E+00 |
| Median | 2.000E+01 | 2.000E+01 | 3.000E+01 | 4.000E+00 | 3.000E+03 | 6.000E+00 |
| Standard Deviation | 1.008E+04 | 1.204E+03 | 2.334E+10 | 9.025E+01 | 9.620E+04 | 3.087E+00 |
| N Samples | 1.747E+03 | 1.796E+03 | 1.872E+03 | 1.956E+03 | 1.835E+03 | 1.835E+03 |
| N Samples (5th–95th Percentile) | 1.582E+03 | 1.667E+03 | 1.800E+03 | 1.838E+03 | 1.777E+03 | 1.777E+03 |
| N Samples (Z-score <= 3) | 1.740E+03 | 1.794E+03 | 1.869E+03 | 1.936E+03 | 1.797E+03 | 1.797E+03 |
| Trimmed Mean (5th–95th Percentile) | 2.162E+01 | 2.843E+01 | 8.386E+01 | 7.494E+00 | 1.679E+04 | 5.866E+00 |
| Trimmed Mean (Z-score <= 3) | 4.242E+01 | 3.209E+01 | 7.031E+05 | 1.076E+01 | 1.939E+04 | 5.858E+00 |
| 95% Confidence Interval (CI), Lower | 1.132E+02 | 9.734E+00 | −4.162E+08 | 1.352E+01 | 2.717E+04 | 5.766E+00 |
| 95% CI, Upper | 1.059E+03 | 1.212E+02 | 1.700E+09 | 2.152E+01 | 3.598E+04 | 6.038E+00 |
| 95% CI (5th–95th Percentile), Lower | 2.074E+01 | 2.737E+01 | 7.602E+01 | 7.048E+00 | 1.531E+04 | 5.729E+00 |
| 95% CI (5th–95th Percentile), Upper | 2.250E+01 | 2.948E+01 | 9.170E+01 | 7.940E+00 | 1.827E+04 | 6.004E+00 |
| 95% CI (Z-score <= 3), Lower | 2.130E+01 | 2.891E+01 | −3.925E+05 | 9.785E+00 | 1.754E+04 | 5.721E+00 |
| 95% CI (Z-score <= 3), Upper | 6.353E+01 | 3.527E+01 | 1.799E+06 | 1.174E+01 | 2.124E+04 | 5.995E+00 |
| 95% CI (Median), Lower | 1.500E+01 | 2.000E+01 | 2.500E+01 | 4.000E+00 | 3.000E+03 | 6.000E+00 |
| 95% CI (Median), Upper | 2.000E+01 | 2.500E+01 | 3.000E+01 | 4.000E+00 | 3.000E+03 | 7.000E+00 |
| Minimum | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 5.000E+02 | 0.000E+00 |
| Maximum | 3.000E+05 | 5.000E+04 | 1.000E+12 | 3.000E+03 | 7.500E+05 | 1.000E+01 |
| Minimum (5th–95th Percentile) | 1.000E+00 | 1.000E+00 | 0.000E+00 | 1.000E+00 | 5.000E+02 | 0.000E+00 |
| Maximum (5th–95th Percentile) | 8.000E+01 | 9.000E+01 | 1.000E+03 | 5.000E+01 | 1.500E+05 | 1.000E+01 |
| Minimum (Z-score <= 3) | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 5.000E+02 | 0.000E+00 |
| Maximum (Z-score <= 3) | 1.500E+04 | 2.500E+03 | 1.000E+09 | 2.500E+02 | 2.500E+05 | 1.000E+01 |
Table A4.2: Summary statistics, outlier trimming, and confidence intervals calculated for variables: long-term value (Q10), long-term value certainty (Q11), expected cost of acquiring 1 map–max (Q17a), expected cost of acquiring 1 map–min (Q17b), and expected cost of acquiring 1 map–best estimate (Q17c).
| Metric | 10: Long-term Value ($USD) | 11: Q10 Certainty* | 17a: Expected Cost of acquiring 1 map ($USD, max estimate) | 17b: Expected Cost of acquiring 1 map ($USD, min estimate) | 17c: Expected Cost of acquiring 1 map ($USD, best estimate) |
|---|---|---|---|---|---|
| Mean | 5.743E+16 | 4.883E+00 | 7.870E+04 | 8.641E+03 | 9.263E+04 |
| Median | 1.000E+04 | 5.000E+00 | 6.000E+03 | 1.000E+03 | 3.000E+03 |
| Standard Deviation | 2.395E+18 | 2.971E+00 | 6.453E+05 | 3.647E+04 | 2.590E+06 |
| N Samples | 1.743E+03 | 1.743E+03 | 1.473E+03 | 1.432E+03 | 1.497E+03 |
| N Samples (5th–95th Percentile) | 1.598E+03 | 1.598E+03 | 1.401E+03 | 1.362E+03 | 1.424E+03 |
| N Samples (Z-score <= 3) | 1.742E+03 | 1.742E+03 | 1.466E+03 | 1.420E+03 | 1.496E+03 |
| Trimmed Mean (5th–95th Percentile) | 1.034E+05 | 5.060E+00 | 2.132E+04 | 3.711E+03 | 9.467E+03 |
| Trimmed Mean (Z-score <= 3) | 5.741E+13 | 5.077E+00 | 4.394E+04 | 6.306E+03 | 2.584E+04 |
| 95% Confidence Interval (CI), Lower | −5.510E+16 | 4.747E+00 | 4.572E+04 | 6.751E+03 | −3.867E+04 |
| 95% CI, Upper | 1.700E+17 | 5.020E+00 | 1.117E+05 | 1.053E+04 | 2.239E+05 |
| 95% CI (5th–95th Percentile), Lower | 9.245E+04 | 4.926E+00 | 1.944E+04 | 3.386E+03 | 8.676E+03 |
| 95% CI (5th–95th Percentile), Upper | 1.144E+05 | 5.194E+00 | 2.321E+04 | 4.036E+03 | 1.026E+04 |
| 95% CI (Z-score <= 3), Lower | −5.519E+13 | 4.943E+00 | 3.733E+04 | 5.543E+03 | 1.716E+04 |
| 95% CI (Z-score <= 3), Upper | 1.700E+14 | 5.211E+00 | 5.056E+04 | 7.069E+03 | 3.452E+04 |
| 95% CI (Median), Lower | 1.000E+04 | 5.000E+00 | 5.000E+03 | 1.000E+03 | 2.500E+03 |
| 95% CI (Median), Upper | 1.000E+04 | 5.000E+00 | 1.000E+04 | 1.000E+03 | 5.000E+03 |
| Minimum | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| Maximum | 1.000E+20 | 1.000E+01 | 2.000E+07 | 1.000E+06 | 1.000E+08 |
| Minimum (5th–95th Percentile) | 5.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| Maximum (5th–95th Percentile) | 1.000E+06 | 1.000E+01 | 2.000E+05 | 4.000E+04 | 8.000E+04 |
| Minimum (Z-score <= 3) | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 | 0.000E+00 |
| Maximum (Z-score <= 3) | 1.000E+17 | 1.000E+01 | 2.000E+06 | 1.000E+05 | 5.000E+06 |
- Trimmed statistics for Question 11 correspond to indices preserved while trimming Question 10.
Table of Contents
- Abstract
- Acknowledgements
- Executive Summary
- Chapter 1: Introduction
- Chapter 2: Study Objectives and Methodology
- Chapter 3: Stakeholder Assessment of Map Producing Agencies
- Chapter 4: Cost for Geological Mapping
- Chapter 5: Geological Mapping Program Activities — Critical Components
- Chapter 6: Benefits of Geological Mapping: Quantitative Assessment of Responses to Stakeholder Questionnaire
- Chapter 7: Geological Map Demand and Economic Estimates of Costs and Benefits
- Chapter 8: Regional Variations in Costs and Benefits of Geological Mapping
- Chapter 9: Quantitative Value Assessment from Independent EPA Data
- Chapter 10: Qualitative Assessment of Value of Geological Maps by Stakeholders
- Chapter 11: An Economic Model of General Geological Mapping Applications
- Chapter 12: Stakeholder Input about Future Geological Mapping
- Chapter 13: Lessons Learned and Suggestions for Future Analyses
- Chapter 14: Summary and Conclusions
- Appendix 1: Cost Sheet Template
- Appendix 2: Questionnaire to Stakeholders
- Appendix 3: Example Solication Letter Requesting Stakeholders to Participate in National Cost-Benefit Assessment
- Appendix 4: Summary Statistics, Outliers, and Confidence Intervals
- Appendix 5: Annual State Geological Survey Map Views
- Appendix 6: Regional Cost-Benefit Analysis Datasets
- Appendix 6a: Questionnaire Data Schema
- Appendix 6b: State Geological Survey Reporting Schema
- Appendix 7: Chapter 8 Supplemental Figures and Tables