In response to office workers’ worries about the health risks associated with using video display terminals (VDTs), researchers asked office workers to estimate both the amount of time they had spent using VDTs and how often they had suffered headaches over the previous year.
Conclusion (to conclude that)
VDTs cause headaches.
Evidence
Researchers conducted a survey asking office workers to estimate their VDT usage and frequency of headaches over the past year.
The survey showed frequent VDT users suffered headaches more often than other office workers.
Evaluate
This argument involves correlational reasoning: it observes a correlation between VDT usage and headache frequency and concludes a causal relationship.
CUROUS FACT: why is VDT usage correlated with headaches? EXPLANATION: VDT usage causes headaches.
To undermine the argument, we should consider alternative explanations for the observed correlation or demonstrate that the VDT usage doesn't actually cause headaches.
A common pattern to consider is Reverse Causality, where possibly the headaches caused people to think they spent more time using VDTs, or Third Factor, where some other variable causes both headache frequency and VDT usage estimation.
Goal
Let's find an answer that suggests an alternative explanation for the correlation, such as a factor that could cause both increased VDT usage estimation and headaches or that undermines the plausibility of the idea that using VDT could cause headaches.