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工作要求與工作控制的交互作用對倦怠與學習努力之影響：公平知覺之干擾角色
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6. Research Limitations
This study is cross-sectional, and thus, it is not clear whether the observed interactions
among PF, JD, and JC persist over time. Future research that examines these relationships
longitudinally may need to provide more information on the mechanism of the interactions
of JD and JC of the Karesek model. Because our data were collected from a single source,
the data may result in common method bias. However, as the above statement shows that our
treatment of the data and the method used in data analysis followed procedures described by
Podsakoff et al. (2003), this study may exclude the common method bias. Our sample was
drawn from car salespeople only, and therefore, this limits the generalizability of the results.
Future research may collect data from other professions to enhance external validity.