Using the Design Tool for Inventory & Monitoring (DTIM) Chip Scott October 6, 2009

Transcription

1 Using the Design Tool for Inventory & Monitoring (DTIM) Chip Scott October 6, 2009 The Design Tool for Inventory and Monitoring (DTIM) is an MS Excel spreadsheet that assists you in meeting your inventory and monitoring information needs. The steps are: 1) to identify your reasons (Broad Objectives) for monitoring, 2) identify the monitoring questions to be asked, 3) identify the metrics needed to answer those questions, and 4) use existing data to evaluate if they are sufficient to answer the questions. If more data are required, then the Design Tool helps to specify the precision requirements, and then computes the inventory costs so that the design (sample sizes) can be adjusted and optimized to meet the information needs. 1. Open the document, e.g., NFS Design Tool.xls 2. Excel 2007 uses security measures to prevent the program from harming your computer. To enable the program, you can do one of several things here is the easiest. If you have already done this before, go to step Click on the Office Button at top left. 4. Click on Excel Options bottom right. 5. Click on Trust Center middle left 6. Click on Trust Center Settings middle right 7. Click on Trusted Locations top left 8. Click on Trust Center middle left 9. Click on Add New Location center bottom 10. Click on Browse middle right 11. Navigate to the current directory or a directory above it, then OK. 12. Then click OK until you get back to the form. 13. Then exit and re-enter Excel so the new settings take effect. 14. Start with the Objectives tab. 15. Note the green blocks are the ones to fill in. The blue blocks are computed by the program. 16. The purpose of the Objectives tab is to identify the Broad Objectives of the study. 17. If on a National Forest, fill in the Forest Plan Desired Condition column with those that relate to sampling plots. Also fill in the Forest Monitoring Question for each Desired Condition. Try to write the Question in a generic way, if possible. Specifics can be provided by inserting a Comment for the question. For each Desired Condition, identify the Broad Objective most closely aligns with it. 18. Example: the Environmental Management System (EMS) will be used to monitor our progress toward the Desired Condition of Achieve the stated objectives of area by Forest Type and Stand Size class. The related Monitoring Questions are What are the areas by Forest Type and Stand Size class on the Forest and in the Ecosubsection? How do these compare to the objectives? Are we moving toward them? The related Broad Objective is 2 (Ecosystem Restoration). Note that the Broad Objective selected will turn blue and will be labeled as Active. 19. You can repeat for each Desired Condition or go through the remaining steps through the Precision tab then return to Step 6. 1

2 20. To highlight the current Broad Objective, click on the Highlight Row s Objectives button. To show the questions for all Broad Objectives, click the Show All Rows button. 21. When ready, click on the Questions tab. 22. The screen is split so that you can see the list of Broad Objectives and selected Questions at the top, and the list of all Generic Questions at the bottom. 23. The default Generic Questions are listed for each Broad Objective that was used on the Objectives tab. The Generic Question numbers in front of the ampersand & are the Primary Questions and those after it are considered Secondary Questions. Only the ones in front of the ampersand are used. 24. To highlight the Primary Generic Questions for the current Broad Objective (click on any cell on the row to select it), click on the Highlight Row s Questions button. To show the questions for all Broad Objectives, click the Show All Rows button. 25. Edit the values listed, such as moving a Secondary Question to the Primary portion of the list. Use the list of Generic Questions on the bottom half to select question numbers to insert. Move any Primary Questions listed for a Broad Objective that are not needed to the Secondary Question position (after the & ). 26. To restore the default Questions for a single row, click on any cell in that row, then click on the Restore Default button. 27. Repeat for every Broad Objective, then click on the Metrics tab. 28. This screen is also split so that you can see the list of Generics and selected Metrics at the top, and the list of all Metrics at the bottom. 29. The default Metrics are listed for each Generic Question that was used on the Questions tab. The Metric numbers in front of the ampersand & are the Primary Metrics and those after it are considered Secondary Metrics. Only the ones in front of the ampersand are used. 30. To highlight the Primary Metrics for the current Generic Question, click on the Highlight Row s Metrics button. To show the questions for all Generic Questions, click the Show All Rows button. 31. Edit the values listed, such as moving a Secondary Metric to the Metric portion of the list. Use the list of Metrics on the bottom half to select question numbers to insert. Move any Metrics listed for a Question that is not needed to the Secondary Metric portion (after the & ). 32. To restore the default Metrics for a single row, click on any cell in that row, and then click on the Restore Default button. 33. Repeat for each Generic Question, and then click on the FIA Info. Tab. 34. Fill in the acreage of the population to be sampled. The acreages of the National Forests can be found using the link (G4). Fill in the other cells in green based on information from FIA, FIDO, EVALIDatorPC, or just copy the numbers from line 8 into line FIA Field Guide links are provided on the national website, and on each of the four regional FIA unit websites. 36. Click on the Precision tab. 37. Example: line 4 is an example of the table of estimates used to answer the Monitoring Question for EMS example. 38. To view all combinations for Forest Desired Condition/Question and Generic Questions, click on the Click to Append New Tables button. If only some rows were highlighted on the Objectives, Questions, and Metrics tabs, then you will be asked if you wish to 2

3 continue. If you do, then only the highlighted rows will be used when creating the rows in the Precision tab. It will take a minute to create the lines. Please wait. 39. If using the program for the first time under Excel 2007, you may get an error message. This is likely a reference library problem. Do the following: a. Click on Deverloper tab, then Visual Basic (else Alt-F11) b. Click on Tools c. Click on References d. Uncheck anything in the list that starts with "Missing" e. Click OK f. Save g. Close the Visual Basic window. 40. Each line represents one or more tables. Note the Metrics column includes one or more default Metrics to use to address the question. If you wish to create more than one table from a line, click on the Copy Line button. 41. Enter the Row, Column and Page By Variables the categorical variables used to display the estimates for the Metric. Note that as you fill in the By Variables, the table description appears in the Table Name column (#2). The By Variables are listed on the Pick List page, along with the Metrics and Forest Questions. 42. To display the Pick List, click on any field in the row of interest, and then click on the Show Questions/Pick List button. The screen is then split with the current Desired Condition and current Monitoring Question shown along with the list of Phase 2 and 3 Metrics and the By Variables listed by Plot/Condition level and Tree/Other level. To show the Desired Condition and Monitoring Question for a different line, click anywhere on the line, then hit the Show Questions/Pick List button 43. The next step is to determine the precision requirements. But since there are likely to be many rows and potential tables, we recommend focusing only on those tables for which the precision of the results is critical to decision making. The following steps should be done one row at a time: a. Fill in the Row, Column, and Page (optional) fields. b. Fill in a note in What Cell? to indicate which cell in the table is the focus for the precision level, such as area for a certain forest type. In general, we recommend using the table total. c. Fill in Scale, such as District or Ecoregion. In general, we recommend using the whole Forest (default). d. Fill in the Confidence Interval Half-Width. For example, a value of 10% means that the confidence interval will be plus or minus 10% of the estimate. e. Fill in the Confidence Level (1 α). FIA reports sampling errors such that they can be used to form 68% confidence intervals (1 standard error). For making decisions, sometimes an 80% or 90% level is used. A 95% confidence interval is twice as wide as a 68% confidence interval and is generally only used in research settings. f. Using FIA s FIDO estimation tool ( EVALIDatorPC (see EVALIDator Instructions.doc), or another source, fill in the estimate for the table cell of interest. See Step 39 below on how to use the Copy and Paste Estimates buttons. 3

4 g. Verify the current sample size. For FIA data, this will automatically differ based on whether it is a P2 or a P3 metric. h. Fill in the Sampling Error as a percent of the estimate. This is how FIDO and EVALIDatorPC present the sampling errors. See Step 39 below on how to use the Copy and Paste Estimates buttons. i. The Coefficient of Variation (CV%), the required sample size for current estimates, and the resulting Sampling Error % are then displayed. j. This same process is repeated for the change attributes. However, if there is no interest in the estimates of change for this attribute or there are no estimates, then you can skip this section. k. Example: for the EMS example, the estimate and sampling % were entered, so the estimated sample size was shown. l. Start by filling in the number of years between remeasurements (the cycle length). In the East this is typically 5 years. In the West it is typically 10 years. m. Fill in the Confidence Interval Half-Width. For example, a value of 10% means that the confidence interval will be plus or minus 10% of the estimate. n. Fill in the Confidence Level (1 α). FIA reports sampling errors such that they can be used to form 68% confidence intervals. o. Using FIA s FIDO estimation tool, EVALIDatorPC, or another source, fill in the estimated change for the table cell of interest, typically expressed on an average annual change basis (periodic change divided by the remeasurement interval). p. Verify the current sample size for the metric. For FIA data, this will automatically differ based on whether it is a P2 or a P3 metric. q. Fill in the Sampling Error as a percent of the estimate. This is how FIDO and EVALIDatorPC present the sampling errors. r. Optional: fill in the Value to Compare with Change Estimate. Use to compare the estimated change to a threshold of change or to a target value. See the next column for the resulting estimate of the Power to detect the difference between this value and the estimated change (column W). For example, the Forest may have a Desired Condition statement saying they want increase a forest type by 5%. s. The Power (or ability) to detect a difference between the Target (column AD) and Actual change (column W) is displayed. Numbers closer to 100% are desirable. t. The required sample size for current estimates and the resulting Sampling Error % are then displayed. 44. Once all the priority tables are completed, then scroll to the last few columns. The minimum sample size for P2 and P3 plots are shown. 45. Click on the Sample Size tab. Close the Pick List screen, and then maximize the top screen. The current sample sizes are shown (from the FIA Info. Tab). The minimum required sample sizes are then displayed. Then the numbers of P2 Only and P3 plots that would need to be added are shown. P2 Only means those plots on which no P3 measurements are taken. All P2 measurements are taken on P3 plots. Enter the costs of a P2 Only plot and of a P3 Plot. Then costs are then annualized and totaled. 46. To see which tables have the highest sample size requirements, see row 13, then go to those rows on the Precision tab. Perhaps some adjustments to the precision requirements would be appropriate, thus lowering the cost of the survey. 4

5 47. The focus of the Precision tab is on a single cell within each table. To see what the whole table looks like, create the table using EVALIDatorPC. The output from EVALIDatorPC is in HTML format. Open the file either from EVALIDatorPC, Windows Explorer, or a browser. 48. Select the entire HTML file by entering Ctrl+A (control A), then copy all of the selected text with Ctrl+C (control C). Else you can click on Edit, then Select All, then Edit, Copy. 49. Return to the Design Tool and select the EVALIDator tab. Click on the Paste Data from EVALIDator button. This pastes the data from EVALIDatorPC into the EVALIDator tab, and then moves to the Estimates tab. 50. The EVALIDatorPC table of estimates is now displayed. If the table contains multiple pages, the Design Tool tells you so. To display different pages, use the arrow buttons in F Note that you can click on an estimate, and then on the Copy Estimate button. You can then go to the Precision tab, and then click on the Estimate cell and hit the Paste Estimate button. Not only does this paste the estimate into column O, but also its sampling error % into column R. 52. Click on the Sampling Errors tab. The percent sampling errors are shown in the same format as the estimates. Note that the color coding of the sampling errors is: <25%, 25-50%, and >50%. 53. The sample sizes are displayed on the top two rows. D1 is the number of P2 plots. H1 is the intensification factor. The default is 1. Click on the arrow buttons (H2) to change the intensification factor and the new sample size in F1. Note that the sampling errors below will reflect the expected change in sample size and the colors may change (improve). 54. Steps are used to determine the effect of the chosen sample size on the sampling errors of whole tables, and then to be able to evaluate other options for sample sizes. 55. To evaluate other EVALIDatorPC tables, close the HTML file, create another, open it, and then repeat steps Once the desired sample size finalized, the Design Tool effort is done. Next step is to work with FIA/NIMAC to identify the locations of the additional (intensification) plots. 5