HCD.24:4.3 - Choose and present comparable material

Use a single work when its relevant property can be judged directly. Use comparison when an otherwise hidden relation becomes discernible through another case. Make the comparable parts and their conditions available together: for example, each case’s observation, model assumption and recommendation. Equal document length and a common template do not make unlike purposes comparable.

Ask what difference warrants a different judgement on the selected criterion. A work can be preferable on one property and inadequate on another. Keep legitimate alternatives and incomparable results available; do not force a total ranking when the question does not support one.

For a sequence of comparisons, retaining one familiar case can reduce rereading while introducing another contrast. Budget the reading and context-switching cost. Long recordings may require permitted aligned excerpts with enough surrounding context. If abridgement removes the decisive relation, obtain a better representation or choose another exercise.

For confidential work, use a permitted fragment, a constructed counterpart retaining the target relation, or a reviewer with appropriate access. A blanked-out assumption may make the review impossible. Preserve that limitation rather than ask the reviewer to guess. HCD.25 develops the related problem of comparing projects for transfer.