Why users get lost: Investigating conciseness and clarity issues in instruction manuals

Concise and clear instruction manuals are essential because they reduce user errors, lower cognitive load, and support safe and efficient product use. This study investigates how linguistic features that undermine conciseness and clarity – such as weak expletives, nominalizations, verbose connectors, vague markers, and ambiguous phrasing – affect the usability of contemporary instruction manuals. The research aims to identify the most frequent conciseness-reducing constructions in real-world documentation and demonstrate how revising them can improve readability and user comprehension. To achieve this, a corpus of 70 instruction manuals for household appliances and consumer electronics was compiled, totalling 709,964 words and 944,193 tokens. The manuals, produced by 14 international companies, were analysed quantitatively to determine the frequency of selected linguistic features, and qualitatively to assess their contextual appropriateness and propose clearer revisions. The results show that weak expletives occur several hundred times and frequently delay core information, reducing immediacy in both safety and procedural instructions. Nominalizations were less frequent but consistently increased syntactic complexity. Verbose connectors appeared widely and offered substantial opportunities for simplification. Across all categories, revised versions demonstrated shorter, more direct, and more actionable phrasing without loss of technical accuracy. The study concludes that systematic reduction of wordiness, vagueness, and ambiguity has the potential to enhance clarity, reduces cognitive burden, and supports more effective user interaction with technical products, offering evidence-based guidelines for improving instructional documentation.