HCD.6:5 - Archetypal Grounding

HCD.6:5.1 - Pump Explanation and a Pressure Change

The stipulated demonstration begins with a pump delivering 100 m³/h at 400 kPa and 20 kW. After a controller change, measured flow remains 100 m³/h and power becomes 22.4 kW, while comparable pressure data are absent. The worked explanation calculates the 12% rise in energy per volume and keeps resistance, regulation efficiency, and measurement error as rivals.

The task supplies the domain comparison: at the same flow and previous efficiency, increased pressure requires greater power; reduced regulation efficiency can also increase electrical demand. A pressure value near 448 kPa would support increased resistance under those conditions, while a value near 400 kPa would direct attention toward regulation efficiency. Neither value establishes a unique cause by itself.

The controller log and four specialist-hours are available. The supplied complete measurement contributions cost one hour for independent power, one and a half for flow, and one and a half for pressure; they include safe preparation, measurement and result return. A day-long shutdown is outside the allowed arrangement. The learner has ninety minutes to justify the observations and next decision, including explanation and comparison. For the selected pressure branch, changing the receiving engineer’s next diagnostic question warrants the remaining specialist contribution and the learner’s effort, including displaced work. Selection does not supply a pressure result.

The first attempt receives independent measurements of 22.3 kW and 99.5 m³/h, with uncertainties of 0.2 kW and 1 m³/h respectively. Ask the person to compare like quantities and use both uncertainty bounds. Even the lowest new ratio, 22.1/100.5, exceeds the stipulated baseline 20/100; this weakens the measurement-error explanation under the supplied conditions. After the power and flow contributions, one and a half specialist-hours remain for pressure. The learner can select that observation and explain how its possible values change the resistance/efficiency comparison while keeping the cause unresolved.

The target action is conditional explanation and a present response suited to the available basis, not arithmetic alone. In a later variant without a worthwhile obtainable observation, the learner can finish the qualified explanation with its live rivals and return that account while leaving a resistance-specific remedy unselected. A unique cause remains unproved. A renamed machine with the same numbers would add no useful variation; neither does a generic request to collect more data.

HCD.6:5.2 - Ticket Load after Duplicate Removal

Four people each have six active-processing hours per day. Incoming records rise from 50 to 80 and each distinct request takes 18 minutes. The initial worked case shows that 50 and 80 distinct requests require 15 and 24 person-hours; the observed queue alone does not establish lower individual productivity.

In a stipulated variation, the 80 records include 20 duplicate messages attached to existing requests, leaving 60 distinct requests. The target action is to recognize that the unit of account changed before calculating 18 person-hours of active processing.

Now leave the duplicate count unknown and ask whether the day’s requests fit the stated active-processing capacity. There can be no more than 80 distinct requests: at 18 minutes each, they require at most 24 person-hours, equal to the four people’s supplied capacity. Return that sufficient upper bound and keep the exact count unknown. The answer concerns active effort under the stipulated processing assumptions; it establishes no queue-clearance, response-time or safety guarantee. Obtaining the count is unnecessary for this answer.

Change the receiving use to an allocation that needs the exact active-processing load of these requests. The upper bound no longer supplies that quantity. Stipulate an authorized existing request view and five minutes of available coordinator time to open it, resolve the duplicate labels and check the total. Correcting the allocation warrants that obtainable burden. Obtain the count for this use; until it is available, retain the upper bound with the exact allocation unresolved. If the view supplies 60 distinct requests, the processing load is 18 person-hours. The five minutes of coordination are an additional cost, not request-processing time or free work.

These cases distinguish a changed unit, a sufficient bound and a receiving use that needs another quantity. Merely replacing the support team with a warehouse would not test those distinctions.

HCD.6:5.3 - FW7 Refusal and FW8 Continuation

The first engineering case supplies a vendor report for FW7 while the intended release configuration requires HW3/FW8/SCHED2. The correct action is to identify the mismatch and withhold that use; a correct financial calculation cannot repair incompatible evidence.

The varied case supplies a report for HW3/FW8/SCHED2, confirms mandatory checks, and leaves 24 test hours. Ten changes in three homogeneous batches require 23 hours. The person should propose the bounded ten-change use and preserve the continuing queue when demand is twelve. Repeating the earlier refusal is now wrong because compatible evidence is present. When available time falls to 22 hours, promising ten changes becomes unsupported again.

This task family makes evidence applicability and the resource calculation jointly visible. It tests a warranted refusal, a supported continuation, and a changed constraint rather than rewarding universal caution.

HCD.6:5.4 - AI-Supported Practice without Attribution Drift

AI may propose sources, calculations, alternatives, or draft wording in a practice task. The task description states which actions the person still performs: checking decisive references, configuration, assumptions and calculations; selecting the Method; explaining the result; and returning unsupported claims. A later attempt may remove AI for a narrow independent contribution while retaining supplied tables and a calculator. The supported and changed-support attempts remain separate in the practice history; neither is silently upgraded to transfer or retention evidence.

HCD.6:5.5 - Correct the Same Action before Adding a New Condition

A trainee must enter a measurement and its unit in an inspection record. The teaching data give 2.4 mV; the criterion is to preserve both the number and unit. Design the first task with a worked row available if the trainee needs it. If the trainee writes 2.4 V, feedback points to the unit on the supplied reading and asks the trainee to correct the entry. The same reading is suitable for this correction: changing it would add a different demand before the present action has been repaired.

That corrected entry is a useful supported practice result. When the later question is whether the trainee independently preserves units on a new reading, supply another reading and withhold the answer-bearing worked row. If later work also requires unit conversion, a separate variant can ask for 0.0024 V to be entered in a column marked mV, whose correct value is 2.4. Select that variant only for the conversion target. Each task keeps its own help and conclusion; the design alone establishes no learner performance.

HCD.6:5.6 - Two Pathways and an Observation that Changes the Model

Continue the fictional Coordinator-N24 case in HCD.4:5.5. The domain criterion is to count distinct work requests, multiply by the supplied 18 minutes per request and qualify the result as active processing effort. Ordinary source tables and a calculator remain available. A teacher may help during learning; during the later observation no teacher or AI supplies the unit choice. N24’s calculation with a supplied unit is already supported, so neither route reteaches multiplication.

The practitioner has two plausible development Methods: comparison of contrasting cases followed by explanation and practice, or supported whole-task completion followed by explanation of its consequences. Both are hypotheses for this learner, with different routes to making unit selection available.

Both fit the stipulated ninety learner minutes and 120 teacher minutes. N24 and the responsible teacher choose A within that authorized practice allocation: existing calculation makes its smaller preparation and practice burden credible, and there is no current evidence that B’s additional guided completion is needed. The shared preference is to obtain independent unit selection while preserving calculation and the effort-only boundary, then prefer lower burden. Expected learning effectiveness remains uncertain; A is a reversible choice, not a demonstrated winner. B remains a supported alternative if the contrast cannot be understood or acted upon from the learner’s present preparation. A learner unable to complete the operation even with the unit supplied would need a different entry and comparison.

In the constructed history, A’s learning and correction tasks are completed. N24 can explain the relation in the paired tables. The four fresh observation tasks then vary service context and salient heading separately. The record identities and duplicate groups are new, including where totals repeat. Each has the request keys and record details needed to distinguish duplicates; each asks for active processing effort. Request rate, delay and queue clearance are outside the question. The teacher observes the first unit choice and calculation and gives no correction until all four first attempts are recorded. In all four recorded responses, N24 explicitly labels the reported quantity as active processing effort and makes no claim about response time or clearing the queue; this preserves the separate scope criterion even when the chosen count is wrong.

Calculation is correct for each chosen number. Independent selection varies with the salient label in both contexts. Model M0’s single familiar-before-unfamiliar ordering cannot adequately describe this profile: N24 shows the intended selection in an unfamiliar context while still missing it in a familiar one. The evidence does not identify a causal label effect or establish population-wide independence; order, case differences and the small sample remain limits. For this local decision, it warrants replacing one familiarity-based position with descriptions that retain the cue condition.

Model M1 therefore distinguishes selection when a compatible cue highlights the unit from selection that withstands a misleading record cue, while retaining calculation and whole-result qualification separately. It drops the assumption that a successful new-context response entails reliable selection in familiar formats. The new transition hypothesis is that comparing incompatible labels with request identities, followed by a learner-generated unit check, may make selection less cue-bound. A fresh task with a misleading heading can weaken that hypothesis. An invalid or ambiguous request table would instead return for task repair.

This changes the remaining pathway. The teacher proposes a twenty-minute addition for cue contrast, correction and a fresh first response; five preparation minutes and fifteen contact minutes take twenty teacher minutes, with the remaining five learner minutes used for an independent attempt. The resulting 80 learner minutes and 100 teacher minutes remain within the original allocation. The practitioner preserves the supported arithmetic and target; simply moving to a harder domain or repeating arithmetic would not address the observed difference. If the new attempt still follows the misleading cue, return to the interpretation and learning mechanism; do not force a higher label. HCD.14 owns that bounded revision.

The three accounts now differ visibly:

• Model: M1’s condition-qualified descriptions and revised relation, including an untested cue-resistance transition.
• Selected pathway: A, revised to include the proposed twenty-minute cue-focused opportunity instead of an assumed next harder stage.
• Trajectory so far: initial independent miss, helped grouping and correction; then A’s learning attempts, explanation and four recorded fresh responses. Sixty minutes of the selected allocation have occurred. The new twenty-minute opportunity has not yet occurred.

The case shows model and plan revision without claiming that the revision itself changed N24. The new-context responses are local evidence; broader transfer, delayed retention and causal programme effectiveness remain separate questions.