“…Here, we define a ‘quantitative’ ordinal scale as one that comprises a number of categories of known, specified ranges of numeric values, as described by Hartung & Piepho () – for plant disease assessment purposes these ordinal scales are generally based on the percent ratio scale relating to area with symptoms, including the Horsfall–Barratt (H–B) scale (Horsfall & Barratt, ). But other scales subdividing the percent scale into different sized intervals designated by continuous numbers might also be used (Horsfall & Heuberger, ; Hunter & Roberts, ; Hunter, ; Stovold & Smith, ; Salamati & Tronsmo, ; Kolkman & Kelly, ; Koitabashi, ; Kora et al ., ; Lazarovits et al ., ; Nitzan et al ., ; Ghose et al ., ; Vieira et al ., , ). Because of resolution, precise data on the 0–100% scale are almost always going to be more informative compared with that from an ordinal scale (Hartung & Piepho, ), but the latter has the advantage of being easier for raters to learn, and quicker and cheaper to implement.…”