HCD.10:4 - Solution
Use the target action, prior episode evidence, and intended later conditions to select only the practice feature changes that have a named purpose. Specify variation, timing, retrieval, sources, support, interleaving, and challenge separately; observe the resulting action; and keep, reverse, or revise the progression when its assumption fails.
HCD.10:4.1 - Bind the Target, History, and Later Conditions
State:
- the human holder, target action, selected Method, representative task family, domain criteria, protected errors, and intended later Work;
- the relevant HCD.9 attempts, first-response conditions, help received, corrections, retries, unresolved difficulties, and intervening practice;
- the later conditions that matter: task variation, configuration, source and tool access, AI use, provider help, time pressure, consequence, and horizon;
- the current basic operation the learner can or cannot yet perform and the uncertainty that remains; and
- the receiving use of the next observation and the stronger HCD.11–HCD.13 inference, if any, that remains separate.
Do not select a harder schedule from completion or confidence alone. If the prior attempt does not identify the action and support state, repair that evidence or run a bounded HCD.9 episode first.
HCD.10:4.2 - Select the Smallest Change that Can Answer the Question
Use this discrimination table:
| Question about the next practice | Candidate change | Required statement |
|---|---|---|
| Does the learner change the action when a deciding condition changes? | variation | Which condition changes, which action should be preserved or changed, and which rival response is exposed? |
| Can the learner perform another episode after a material interval? | spacing | Which repeated episode, separated times, interval rationale, intervening activity, and later observation are used? |
| Must a contribution be recovered without reopening a source? | retrieval | What is retrieved, what remains supplied, why unaided recovery matters, and what support is still allowed? |
| Must the learner distinguish which Method or case family applies? | interleaving | Which alternatives are mixed, which similarities cause confusion, and what selection explanation is required? |
| Is stable performance ready for a changed level of challenge or help? | progression | Which feature changes, what prior evidence supports the change, and what condition pauses or reverses it? |
Select several changes in one episode only when their contributions and failure interpretations remain recoverable. Otherwise change one decision-bearing feature at a time or create comparable branches.
HCD.10:4.3 - Design Variation around a Warranted Change of Action
Choose a condition that can make the correct action differ: configuration FW7 versus FW8, 24 versus 22 test hours, 80 records versus 60 distinct requests after duplicates, pressure near 448 versus 400 kPa, complete versus missing source information, or a different authority or support boundary.
State the expected discrimination before the attempt. A useful variant can require a justified refusal, supported continuation, changed calculation, specific request, different Method, or preservation of the earlier action. A new story with the same values and answer is surface variety, not evidence-bearing variation.
HCD.10:4.4 - Space Repeated Episodes without Smuggling in Other Changes
Name the earlier episode, later episode, separated times, interval, and intervening activity. The interval should follow the intended use horizon, practical opportunity, prior access, risk, and available evidence rather than a universal spacing number. Record any practice, work use, feedback, or source encounter between the episodes.
Then specify separately for each episode:
- whether the learner retrieves a contribution or receives it;
- which sources, patterns, data, tables, calculators, tools, and AI are available;
- which human, peer, teacher, specialist, cue, or worked-example support is permitted and received;
- whether the task, configuration, time, consequence, or Method choice also changes; and
- what the later attempt can and cannot establish.
Two episodes at separated times constitute spacing even when the same appropriate references and tools remain available. Removing AI or closing a source is a support or source change, not proof that spacing occurred. A later observation after continuing use is not retention without intervening practice merely because a date has passed.
HCD.10:4.5 - Interleave only when Selection Is Part of the Target
Mix task families when the learner must recognize which Method, relation, calculation, check, or response applies and when their similarity makes that discrimination meaningful. Require the learner to state why one route fits and why a serious neighbor does not. Preserve category similarity, order, support, and result so that a failure can be interpreted.
When the basic operation is new or still unstable, begin with blocked or stable supported episodes if that makes the action learnable and observable. Introduce mixing after the learner can perform the constituent action sufficiently for selection to become the real difficulty. Interleaving is a candidate, not a default schedule.
HCD.10:4.6 - Progress Challenge and Support Conditionally
Progress one material feature: increase variation, combine more contributions, shorten response time, add consequence, reduce an answer-bearing cue, change AI or tool support, require a more independent first move, or move closer to later-Work conditions. Keep the protected safety, privacy, authority, and domain constraints.
Use a rule rather than a ladder label. For example: after a successful independent variant, remove the detailed cue but retain source access; after an applicability error, restore the working entry and one discriminating question; after a calculation error, give calculation-specific feedback and retry a changed value; after recurring support dependence, compare supported and changed-support attempts before further withdrawal.
Pause, reverse, or redesign when error becomes unsafe, the learner cannot yet perform the basic operation, support removal changes the intended later task, feedback cannot be used, or the observation no longer distinguishes the progression assumption. No fixed fading path or difficulty increase is required.
HCD.10:4.7 - Differentiate Apparent Failure before Assigning More Practice
When different explanations would lead to different next Work, ask whether the learner failed to recognize applicability, access the needed response or source, express the result, adapt the Method, enact the action, or operate under the changed support. Apply E.23.CAE when its differential is available and material. Its result informs the HCD decision; it does not choose the practice change.
A missing source, unavailable AI, inaccessible interface, invalid task, excessive load, or changed configuration is not automatically capability loss. Repair the direct condition, return to stable supported practice, change the variant, or select another Method as the evidence warrants. Intensify only when the stronger challenge still addresses the diagnosed practice need.
HCD.10:4.8 - Return the Progression and Observation Rule
An HCD.10 result contains:
| Result position | Required content |
|---|---|
| progression boundary | Holder, target action, Method, task family, later conditions, criteria, risks, and receiving use |
| prior evidence | Relevant attempts, corrections, support received, unresolved difficulty, and intervening practice |
| selected change | Variation, spacing, retrieval, source condition, interleaving, support change, or progression feature, each with its purpose |
| episode design | Conditions, separated times where applicable, interval, order, materials, sources, tools, AI, human help, task, and workload |
| expected discrimination | Action to preserve or change, serious rival response, and observation capable of changing the design |
| response rule | Continue, stabilize, pause, restore support, redesign, return to another HCD Method, or request an E.23.CAE differential |
| qualification | What the planned or observed episode can establish and which transfer, retention, or causal claim remains open |
| continuation | Next episode, stronger evidence use, safe stop, unresolved gap, and smallest reopen condition |
A calendar is one carrier of the result, not the result itself. A learning product may implement the selected sequence; HCD.10 retains the human-development purpose, evidence boundary, and revision rule.
HCD.10:4.9 - Recognition and Assurance
Recognition. Use HCD.10 when the next instruction is “make it harder,” “space it,” “mix the topics,” “test retrieval,” or “remove the help,” but the target discrimination, timing relation, source condition, support state, or response rule is missing. The warning sign is a bundled schedule whose failure has no unique interpretation.
Assurance. Stronger reliance needs prior attempt evidence, one target contribution, representative tasks, explicit decision-bearing changes, separated times for spacing, separate retrieval/source/support choices, task-similarity grounds for interleaving, conditional challenge progression, direct risk owners, and an observation with a lowering rule. A scheduled visit or hard task establishes no transfer or retention by form.
HCD.10:4.10 - What Changes in Practice
A practitioner stops asking, “Which spacing and difficulty recipe should everyone follow?” and asks, “Which condition should change this person’s action, when should the task recur, what must be retrieved, which resources and help remain legitimate, why are these cases mixed, and what result will make us stabilize, progress, or back off?”