Blog | quantitativeanalysis

May 16, 2018
1 min

Annual Inspections Done Without Reference to Manufacturer's Specifications

Purpose: To confirm that when new instruments are being evaluated, various solutions are used between 50 and 400 mg/100mls. To confirm that when new instruments are being evaluated, the specified accuracy requirement is +/- 5 percent of the BAC with a precision requirement of +/- 3 mg/100mls under 100 mg/100mls and +/- 2.5 percent for readings greater than 100. To confirm that the purpose of such evaluation is to ensure the accuracy and reliability of breath tests. This proc

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Stephen Biss

Apr 13, 2018
1 min

Change at One Point but Not at Another Point that is Equivalent

Purpose: To suggest that there is empirical evidence in the matter before the Court of change in response by the approved instrument at the lower end of the measuring interval (reading much lower) and at the upper end of the measuring interval (reading slightly higher) without corresponding change in response at the single data point control test level. To suggest that linearity has therefore changed, and in other words, the calibration curve programmed into the instrument, a

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Start By Defining "Reliability" don't focus on "Accuracy"

Stephen Biss

Apr 6, 2018
3 min

Start By Defining "Reliability" don't focus on "Accuracy"

Purpose: To remind the Court, "thing 1" in 258(1)(c) is unconstitutional under Charter 11(d) (R v St-Onge) but is saved by section 1. To remind the Court that 258(1)(c) is saved by section 1 because of Parliament's purpose which is weight consistent with scientific reliability. To demonstrate to the Court that the SCC in St-Onge relied on the paper by Brian Hodgson. To bring that paper before the Court and make it an exhibit. To ask the government scientist to concede the def

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Stephen Biss

Mar 23, 2018
1 min

Response Drifts Over Time

Purpose: To establish that the hypothesis by the ATC/CFS, that any drift in instrument response (what Hodgson describes as significant drift in accuracy and precision over time) will always be caught by a single point control test, is not supported by any empirical study. To establish that there is no study abstracted in Wigmore on Alcohol that establishes the ATC/CFS hypothesis empirically. To confirm that the new calibration curve created after a re-calibration compared wit

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Stephen Biss

Feb 28, 2018
1 min

How to Calibrate - Teach an AI - Build the Inverse Logarithmic Calibration Curve

Purpose: To educate the Court about the Analytical Theory of the 8000C Optical Bench including Emitter, Sample Chamber, Dual Detectors, Inverse Logarithmic relationship, and building the Calibration Curve based on the theory that differing ethanol concentrations have differing % absorption of IR light. To lay the groundwork for the importance of calibration and re-calibration respecting the reliability of any approved instrument. To explain the auto-calibration function of th

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Stephen Biss

Feb 4, 2018
1 min

Uncertainty of Measurement for Lawyers and Judges

Purposes: To simplify the concept of Type A Uncertainty of Measurement to make it more understandable to a trial judge. To obtain an admission from the CFS scientist that Uncertainty of Measurement is not novel science. To explain calculation of average, precision, and standard deviation in simple math terminology. To connect CFS documents that talk about coverage factor with the international literature of Uncertainty of Measurement. #UM #precision #standarddeviation #covera

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Stephen Biss

Feb 1, 2018
1 min

Periodic Inspection Must Be Done Under Stable Lab Conditions

Purpose: To challenge the CFS expert's position that inconvenient data should be excluded for the purpose of calculating precision. To obtain an admission that the local police service is not properly assessing accuracy and precision during periodic inspections because they are not assessing under stable conditions. To illustrate the importance of an O'Connor order requiring production of officer's contemporaneous documentation at the time of the inconvenient data to determin

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Stephen Biss

Jan 31, 2018
1 min

Police Services Use Control Test Data Outside MPE to Calculate Precision

Purpose: To obtain an acknowledgement from a CFS scientist that even though he would exclude data outside (Maximum Permissible Error) 90 to 110 in calculating precision, at least one police service in Ontario is using data outside 90 to 110 in calculations of precision during periodic inspection. #MPE #precision #stabilitytesting #outlier

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Stephen Biss

Jan 30, 2018
1 min

Ignoring Inconvenient Data in Calculation of Precision

Purpose: To challenge the opinion that data outside maximum permissible error (outside +/- 10 mg%) should be excluded from any calculation of precision. The cross-examiner should have called evidence in reply from a statistician or other expert in outliers. #MPE #outlier #precision

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Stephen Biss

Jan 29, 2018
1 min

Defence Methodology Calculating Precision in the Field

Purpose: To establish a better methodology for calculating precision of an approved instrument in service. To apply CFS methodology using control checks re calculation of uncertainty of measurement in blood/urine analysis to evidentiary breath testing. #precision #stabilitytesting #UM

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Stephen Biss

Jan 28, 2018
1 min

Precision Testing Using Only 2 Data Points is Inadequate to Calculate Precision

Purpose: To educate the Court as to the inadequacy of calculation of the instrument's precision by the local police service, close in time to the subject tests. To obtain admissions from the CFS expert as to proper methods for calculating precision. To confirm evidence that the local police had stopped doing linearity checks by the time of this periodic inspection. #annualmaintenance #precision #inspection #stabilitytesting

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Stephen Biss

Jan 27, 2018
1 min

Government Scientists Calculate Uncertainty of Measurement - Why Can't We?

Purpose: To obtain admissions about the use of historical control test data by the Centre of Forensic Sciences in Toronto to calculate standard deviation and uncertainty of measurement. To obtain an admission that the same approach could be used with historical data of Intoxilyzer control tests to prepare statistical data of accuracy and precision at different points in time so as to assess drift in accuracy and precision over time, in other words, reliability. #historicaldat

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Stephen Biss

Jan 24, 2018
1 min

Checking Analytical Variability and Accuracy of the Instrument? Where?

Purpose: To explore the lack of a lab setting when accuracy and precision of the instrument are checked on periodic or annual inspection. To explore the lack of Standard Operating Procedures when accuracy and precision of the instrument are checked on periodic or annual inspection. #analyticalvariability #inspection #annualmaintenance #precision #accuracy #SOPs

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Stephen Biss

Jan 22, 2018
1 min

Distorted Concept of "Accuracy", "Precision", and "Reliability"

Purpose: To remind the Court of the concept of "reliability" used by the SCC in St-Onge. To educate the Court as to the definitions of "accuracy", "precision", and "reliability" used by Brian Hodgson in his paper relied on by the SCC in St-Onge. To focus on drift in accuracy and precision over time from: the manufacturer's specifications, and/or the accuracy and precision of the 8000 that was evaluated, and/or this specific instrument when first placed into service, as compar

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Stephen Biss

Jan 21, 2018
1 min

Attempt to Distinguish from Jackson and Vallentgoed

Purpose: To support argument that the Maintenance History shows that the instrument was taken "out of service", for "consistently low cal. checks" and as a result "requires calibration". Can the matter not be distinguished from Vallentgoed where the maintenance log revealed that the instrument was taken out of service for routine maintenance and periodic re-calibration? To support argument that the Maintenance History reveals that the instrument was taken out of service for a

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Stephen Biss

Jan 19, 2018
1 min

No Sampling of Aging Instruments in the Field

Purpose: To suggest that ATC/CFS scientists cannot provide any scientific opinion of the reliability of aging instruments out in the field without conducting an empirical study of instruments sampled from the field. To suggest that ATC/CFS scientists have no idea whether or not instruments in the field are performing in accordance with manufacturer's specifications. To identify the lack of any system of "verification" in Canada that instruments in the field are performing in

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Stephen Biss

Jan 15, 2018
1 min

Manipulating Control Test Data to Enhance Precision

Purpose: To neutralize the government scientist's assertion that anomalous data should be excluded from calculation of precision. To obtain an acknowledgment of drift in precision over time (see Hodgson definition of reliability) To challenge the propriety of throwing out control test data outside 90 - 100 mg/100mls in any calculation of precision #precision #Hodgson #reliability

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Annual Inspections Done Without Reference to Manufacturer's Specifications

Change at One Point but Not at Another Point that is Equivalent

Start By Defining "Reliability" don't focus on "Accuracy"

Response Drifts Over Time

How to Calibrate - Teach an AI - Build the Inverse Logarithmic Calibration Curve

Uncertainty of Measurement for Lawyers and Judges

Periodic Inspection Must Be Done Under Stable Lab Conditions

Police Services Use Control Test Data Outside MPE to Calculate Precision

Ignoring Inconvenient Data in Calculation of Precision

Defence Methodology Calculating Precision in the Field

Precision Testing Using Only 2 Data Points is Inadequate to Calculate Precision

Government Scientists Calculate Uncertainty of Measurement - Why Can't We?

Checking Analytical Variability and Accuracy of the Instrument? Where?

Distorted Concept of "Accuracy", "Precision", and "Reliability"

Attempt to Distinguish from Jackson and Vallentgoed

No Sampling of Aging Instruments in the Field

Manipulating Control Test Data to Enhance Precision