The WG questions do not address duration. Based on test results, the WG determined that when people answer the Short Set of questions, more often than not, they think of the difficulties they have in their usual state. That is, if someone has a broken leg – and temporarily has difficulty walking – that person tends to answer no difficulty because usually they do not have any difficulty and soon after the bone has mended, they will return to their normal state. Some respondents may answer that they do have difficulty walking even if the difficulty is expected to be temporary. The WG does not consider this to be a problem. At any given point in time there will be a portion of the population that has some temporary difficulty with one or more of the domains covered in the Short Set. Individuals who answer in this way are also temporarily at risk of participation restrictions and in need of accommodations.
There are hidden but significant costs to identifying those with only long-term difficulties. These include: 1) making incorrect assumptions about recovery; i.e. not all those with temporary difficulties will make a complete recovery and would, therefore, benefit from inclusion; and 2) the ability to identify the population that would benefit from universal design; i.e. even those with temporary difficulties will benefit, for the duration of their reduced functional capacity, from accommodations that reduce barriers to participation.
Modifying the questions to direct the respondent to only respond in terms of their usual functioning or to include temporary difficulties involves adding in a long, complex introductory statement. Respondents seldom listen to all of the instructions when survey modules are preceded with such long and wordy opening statements. For example, beginning a series of questions with the following instructions is often counterproductive:
- The next questions ask about difficulties you may have doing certain activities only because of your HEALTH.
- Please think about the last 30 days taking both good and bad days into account. Only consider difficulties that have lasted or are expected to last for 6 months or more.
- Now thinking only about your health I want you to answer these questions WITHOUT taking into account any help.
A respondent has to think of, and remember, all those instructions when answering the questions that follow. Cognitive testing has shown that they do not always take these considerations into account when they respond. Respondents may focus on the instructions at the beginning of the statement or at the end, but they do not recall or consider all, or at times, any of the instructions.
For the reasons discussed above, the WG determined that measurement error (incorrect identification of a functional difficulty) was minimized by not referencing long term difficulties in the questions.