Iranshahr University of medical sciences Scientific Journal of Medical Sciences 2783-4921 2 4 2023 12 01 Can Lawshe and Polit be fitted in one seat? Methodological misconceptions in instrument development 1001 1005 EN Hojjat Shafaee Mohammad Rajabpoor Amir Mirhaghi Journal Article 2022 11 07 2023 12 07 Introduction: Instrument development plays an important role in the methodological design among the studies. The aim is to provide a clear understanding of the key steps in the instrument development process.<br> Methods: A scoping literature review was performed to find instrumentation development approaches. Key search terms were instrumentation, instrument development and content validity. Electronic databases including PubMed and Scopus was searched up to Sep 2022. No additional filter was used. Abstracts were screened to retrieve relevant papers.<br> Results: Seven major instrument development approach were retrieved and summarized. Common misconceptions were i) use more than one scale to stratify clarification or clarify items after content validity phase; ii) use item impact score to report face validity or perform face validity after content validity phase; iii) use both CVI and item impact score to quantify content validity; iv) poor report of CVI of scale and v) using alpha Cronbach as a measure of reliability.<br> Conclusion: It is necessary to strictly follow steps in instrument development process and ensure content validation of scale. It is recommended that premature theoretical framework, redundancy to stratify face validity or content validity, using alpha Cronbach as great lower bound to assess reliability and small sample size to assess reliability assessment must be addressed in the instrumentation studies.<br>