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HomeMy WebLinkAboutPre Post Treatment Comparison Lake Cornelia, Polk 4 23, and 6 10, 2017MB... 125 1 94 0 14 0 11 0 6 1 125 1 10 16 10 6 15 1 0 2 0 2 125 125 125 1 1.903627806544345E-55 10 16 0.2138263361930951 10 6 0.30131277642139143 15 1 2.972558736166963E-4 0 2 0.1556355146175834 0 2 0.1556355146175834 125 1 1.903627806544345E-55 6 1 5.5257153225968525E-2 11 0 6.9361595087582921E-4 14 0 1.1761732458982279E-4 94 0 1.2555924908834871E-34 125 125 125 1 10 16 10 6 15 1 0 2 0 2 125 1 6 1 11 0 14 0 94 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Ceratophyllum demersum Elodea canadensis Absent Present Pre Post Exp Significant change PRE present POST present pre-treatment survey total points post-treatment survey total points Note: p Rename this Sheet! "Rename this Sheet". You must rename this sheet another lake. If you forget to rename the sheet and you try to run another set of data, you will get an error message. Sample Size Problem Increase/Decrease (proportional to # sampling points) 5. Your results are now in worksheet "newsheet". You will see a reminder to 2. Copy/Paste data into cell A1 of worksheet "Enter Data". 3. Calculations are computed automatically. It also records the calculations as numbers instead of formulae. Hit "End" (Do not hit "Debug") and rename the sheet before you try again. 4. Click button :"Click to Move Data". Clicking here moves the data and calculations to workshheet "newsheet" so that worksheet "Enter Data" is ready for another data set. (double click on "newsheet" and rename) before you process data for This Excel Workbook is a tool for comparing changes in species presence/absence data, collected using the Point Intercept method, within a lake over time (e.g. before and after treatment). 1. Arrange presence/absence data exactly as presented in worksheet "Example". There is room for 60 species. 6. Worksheet "ChiTest", and parts of worksheet "Enter Data" are protected and must not be altered. test. We have set the alpha, or Type I error rate at 0.05. This means we have accepted a 5% chance of claiming there is significant change when no real change has occurred. This level is standard in ecological studies. If the test returns a significant result, we know that there is the beta, or Type II error rate at 0.80. This means there is an 80% chance of detecting a significant change if that change is really there. 7. The significance of observed changes is determined by the Chi-square even though the change evaluated was indeed significant. This corresponds to a 20% chance of NOT detecting significant changes, only a 5% probability the observed change is not a true change. We have set expected values must not be too small. If you see the warning "Expected value too small", it means there is not enough information to confidently make a statistical conclusion. 8. In order for the chi-square distribution to be valid, the calculated Pretreatment Filamentous algae Potamogeton crispus Posttreatment All CLP CLP Rake Fullness 3 CLP Rake Fullness 2 CLP Rake Fullness 1 n.s. + - *** CLP Rake Fullness 4 Lemna minor Spirodela polyrhiza Lake Cornelia