HCD.6:4.4 - Design Decision-Bearing Variations

Choose variations from the relation the person must discriminate:

• change a measurement or its uncertainty when competing explanations predict different observations;
• change the unit of account when duplicate events, batching, or aggregation alters the workload calculation;
• change a configuration identifier when evidence is valid for one configuration but not another;
• supply a complete compatible report after an earlier missing-evidence case so the learner must act rather than repeat a refusal;
• change available time, support, task similarity, or authority when those values change the warranted continuation; and
• change the cue that signals which Method applies when recognition and selection are the target.

Select a variation when its intended contribution is needed. Use the smallest change that can distinguish recognition or adaptation from answer recall or generic caution; ordinary acquisition or correction can first use a repeated task. HCD.10 later chooses how variation, spacing, interleaving, progression, or support change should be distributed across practice episodes.