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9990 · 4.4.1

Physical work conditions — practice questions

Practice and worked examples for 9990 Physical work conditions. Short previews only — attempt the full question in MarkScheme against the official scheme.

Worked example 1

A design agency moves to an open-plan office with bright LED lighting and hot-desking. Creative staff report headaches, difficulty concentrating, and more sick days. Using environmental psychology, explain the problems and suggest improvements.

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Noise/distraction: Open-plan increases irrelevant speech effect — background conversation disrupts complex creative work (unlike simple repetitive tasks where social facilitation may help).

Lighting: Harsh LED without daylight can cause eye strain and headaches; lack of natural light lowers mood and circadian alignment (links to 4.4.2).

Ergonomics: Hot-desking may prevent adjusted chairs/monitors → musculoskeletal strain.

Herzberg: Physical conditions are hygiene factors — poor environment creates dissatisfaction even if it cannot alone motivate.

Improvements: Quiet focus pods, adjustable lighting, assigned desks with ergonomic kit, noise zoning.

Evaluation: Open-plan suits collaborative phases (Tuckman performing teams) but not all tasks — activity-based working balances both. Individual noise sensitivity varies.

Worked example 2

An office manager measures the noise levels in a new open-plan office. The average background noise is 65 dB. During a study, they find that for tasks requiring high concentration, error rates increase by 5% for every 3 dB increase above a 50 dB threshold. Calculate the estimated increase in error rate for these tasks due to the current background noise and suggest two evidence-based solutions.

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Step 1: Identify the noise excess. The recommended threshold for concentration-heavy work is 50 dB. The current average noise level is 65 dB. Excess noise = Current level - Threshold Excess noise = 65 dB - 50 dB = 15 dB.

Step 2: Calculate the number of 3 dB increments. The problem states that error rates increase for every 3 dB increment above the threshold. Number of increments = Total excess noise / Increment size Number of increments = 15 dB / 3 dB = 5 increments.

Step 3: Calculate the total estimated increase in error rate. The error rate increases by 5% for each increment. Total error rate increase = Number of increments × Percentage increase per increment Total error rate increase = 5 × 5% = 25%.

Final Answer & Solutions: The estimated increase in error rate for high-concentration tasks is 25%. This is a significant performance decrement.

Evidence-based solutions:

  1. Acoustic Treatment: Install sound-absorbing materials like acoustic panels on walls and ceilings, or use high-partition cubicles. This directly reduces the ambient noise level (the 65 dB measurement).
  2. Noise Masking/Soundscaping: Introduce a constant, low-level background sound, like a white noise generator or specifically designed soundscapes. This can make distracting, intermittent sounds (like conversations) less intelligible and therefore less disruptive to cognitive tasks, as shown in studies by researchers like Banbury and Berry.
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