The hypothesized structure of the Haem-A-QoL was confirmed with evidence provided by item-internal consistency and item-discriminant validity (Table 3).
Item wordings provided by A. Dukes (personal communication, September 23, 2010): How religious are you?
Fig. 4 Histogram of the change in number of principles of natural selection provided by students in a long-response item, before and after instruction.
A decision was made to assess the construct validity of the scale using the following methods: assessment of dimensionality using CFA and item information provided by each item about trust using item response analysis.
Higher values show unexpected responses (noise) or might point to multidimensionality. Lower values point to item redundancy, meaning that the information provided by the item overlaps with the information provided by other items [ 12, 14, 15].
If a student detects all of the correct answers and omits all of the incorrect answers of an item, the student can be expected to understand movement in response to forces in the particular problem context provided by the item.
Item information curves display the information provided by each item (y-axis) at each level of person ability (x-axis).
Because the Rasch model enables consideration of the measurement error (or in other words, the precision of the measurement) at different levels of person ability, we present so-called item information curves that display the information provided by each item at each level of person ability.
Moreover, the IRT analysis revealed that the level of information provided by each item in the social role factor was consistent, but the items in the personal role factor provided different levels of information.
With adaptive testing the user does not see all the questions in the item bank and must rely, for both questionnaire administration and scoring, on a complex computer program provided by the item bank developer.
