Ergonomics: Qualitative and Quantitative Methods

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Ergonomics Qualitative and Quantitative Methods

• Every Method Has Both Qualitative and
  Quantitative Aspects
• There is No Clear Distinction Between Qualitative
  and Quantitative Approaches
• Professional Judgment is Required With Any
  Methodology

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Methods

• Walk-Through and Observation
• Checklists
• Video Analysis (Slow Motion Reviews, etc.)
• Interviews and Discussions
• Symptoms Surveys (Discomfort Surveys, etc.)
• NIOSH Lifting Evaluations
• Psychophysical Evaluations
• Biomechanical Evaluations
• ETC.

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Symptoms Surveys

• Can Sample or Census Workers Within a Facility
• Generally Use a Bi-Polar Scale to Estimate
  Symptoms from Little or No Pain / Discomfort /
  Fatigue to Worst Possible Pain / Discomfort /
  Fatigue
• Can Also Estimate Frequency of Occurrence
• Surveys Can be Performed So That Workers Are
  Anonymous Except for Job Title
• Anonymity Encourages Honesty in Reporting and
  Reduces Over-Reporting and Under-Reporting

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Symptoms Surveys

• One Purpose is to Provide a Baseline Against
  Which to Compare Changes
• Another Purpose is to Identify the Most
  Troublesome Jobs or Tasks
• Symptoms Surveys Can Be a Leading Indicator of
  Injuries
• Claims are a Lagging Indicator of Injuries
• HR Personnel Generally Insist That the Employer
  Be Prepared to Both Share Results With Workers
  and Also Respond to Identified Problems

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Administering Symptoms Surveys

• If a Sample (Rather than Census) Is To Be Taken,
  Operators Should Be Chosen at Random
• Sample Size Should Be Based On Desired Margin of
  Error
• A Census of Workers Should Be Taken Where
  Possible
• Instructions Should Be Provided
• Workers Should Be Allowed To Complete Without The
  Analyst Standing Over Their Shoulder
• Forms Should Be Completed Quickly, Not Taken Home
  Over Night or Otherwise Belabored

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Symptoms Surveys

• Manually Scoring Symptoms Surveys and Compiling
  Results Is Tedious and Difficult Work
• A Computerized System for Scoring and Compiling
  Results Would Be Desirable
• Results May Indicate the Most Stressful Jobs
  Within a Facility