step three.1. Product Selection

According to Samejima’s graded reaction IRT design [22,25], using the marginal limitation possibilities estimator (MMLE), we can get one slope and you can five tolerance (location) parameters for each and every product. No items try ignored of the estimation techniques. New slope parameter is actually a measure of the brand new discerning strength off a product, as well as the place factor procedures new frequency out-of an actions otherwise a mindset. This new mountains and thresholds of the many things were estimated and posted so you’re able to figshare having members to check (discover, doi: /m9.figshare.20024240. accessed towards the ). I took a mountain larger than step one and you can thresholds within [?cuatro, 4] as goods choice standards [17,26]. Rather, we searched the thing attribute contour (ICC), often referred to as the fresh shade line, to aesthetically see the overlap between surrounding categories . If the adjacent groups had extreme overlap, they appeared unreasonable to set her or him given that newest reaction possibilities. Particular impulse groups have been blended or deleted, which decreased the very last possibilities. The financial institution of issues came across the fresh new design assumptions and you will installing the latest data reasonably well weiterlesen →