Table 1 The number of items proceeding to each step of the analysis The number of and examples of items removed at each stage of the psychometric analysis.
Stage of analysis | Number of items removed | Reason for removal | Examples |
|---|---|---|---|
| Â | 1 | Concerns about the way the item was presented | Â |
(a) | 28 | < 10% or > 90% of responses in 'cannot' | Reaching for a cup and taking a sip of water Combing hair at a sink Cycling on a heavily laden bicycle |
(b) | 26 | Significant difference between M and F and/or under and over 85 years | Washing up (easier for older respondents) Crossing the street (easier for younger respondents Preparing a warm meal (easier for female respondents) |
(c) | 26 | Item fit p-value < 0.01 or estimates of β i not stable | Taking oral medication Cycling Getting money out of the bank using an ATM |
In item bank | 79 | Â | See Table 2 |
Total | 160 | Â | Â |