In Likert Scale, Is Ticking Options Consecutively at Two Ends Equally Problematic as Ticking in the Middle?

The popularity of self-report surveys brings to light the issue of insufficient effort responding (IER), where participants lack motivation to respond thoughtfully, thereby compromising data quality. A prevalent form of IER, known as straightlining, occurs when participants consistently select the same response for multiple items, leading to potentially biased outcomes. Typically, researchers apply a uniform threshold criterion across all response options (e.g., nine consecutive identical answers in any option are considered problematic). Considering the diverse or near-normal distribution patterns in questionnaire responses, employing varied thresholds for different options may be more appropriate. This study utilized both simulated data and real, large-scale international survey data to examine the likelihood of straightlining as IER across various options. The findings revealed that legitimate straightlining (non-IER) was more common at the extremes than in the middle options. Moreover, the study highlights the significant risks of incorrectly categorizing non-IER straightlining as IER without corroborating evidence. In conclusion, our results question the conventional approaches to eliminating straightlining, including (a) the application of a uniform cutoff value across different options or adopting stricter criteria for middle options and (b) the direct removal of straightlining as IER without additional verification.