This study is designed to assess the proportion of asthma subjects making critical and non-critical errors made in using ELLIPTA® inhaler compared with other commercially available inhaler devices such as the TURBUHALER®, MDI (metered-dose inhaler), and DISKUS/ACCUHALER®. This study will also assess the ease of use and preference between the ELLIPTA inhaler and the other commercially available inhaler devices. This is a randomized, open-label, placebo, crossover, multicentre study with a single visit. The study will comprise three sub-studies. Subjects will receive inactive treatment (placebo) via the ELLIPTA inhaler and one of the other inhaler devices depending on the sub-study they are allocated to. Only subjects who are naïve to the ELLIPTA inhaler and to one of the other inhalers that will be used in this study will be included. The study will be conducted in the Netherlands and the UK, and comprises one visit only. A sufficient number of subjects (at least 190) with asthma will be screened and 180 will be randomized to one of the three sub-studies. Eligible subjects will be allocated to one of the sub-studies in the following order depending on their experience of using the other inhaler (i.e., depending on which other inhaler they are naïve to).