Event time and availability time
The date an event happened and the date you could use its information are not always the same. Prediction must follow availability time.
| Candidate feature for end-of-W4 prediction | Decision and reason |
|---|---|
| W1-W4 logins already visible | Use: completed and available by the cutoff |
| Programme historically recorded at enrolment | Use the historical version known then |
| Future exam date announced in W1 | Use if the schedule was known then; a future event can have an available planned date |
| W3 quiz score first released in W5 | Do not use: past event, unavailable result |
| Current GPA updated in W6 | Do not use that later version as if it existed in W4 |
| Whole-semester attendance | Do not use: includes activity after the cutoff |
An event can happen before the cutoff while its measurement arrives after it. Conversely, a schedule for a future event can already be known. The prediction system's actual access time determines availability.
Sources: W4 PDF pp. 2-42; L4 Tasks 1-7. All fixed worked values here were recalculated from the supplied examples. These toy rules are teaching devices, not deployable student-support recommendations.
The supplied split tells you which records teach the rules and which records only receive predictions. Keep those roles separate.
Practice problems
Supplementary study questions on the lecture concepts — not verbatim exam questions. Each answer counts toward spaced review.
1. Conceptual understanding
Definitions and distinctions.
A W3 quiz score is released in W5. Can it be used at W4?
An exam takes place in W8 but its date was announced in W1. Can the planned date be known in W4?
2. Application
Apply the concept to a case or calculation.
A week-2 test score is first accessible in week 6. Is it available for a week-4 prediction?
A planned week-8 exam date is published in week 1. What matters for week-4 use?
3. Interpretation and limitations
Evaluate assumptions and justify conclusions.
A GPA is updated in week 6. Can that version automatically stand in for the week-4 GPA?
Why reconstruct historical input availability?
Explain it in writing
Self-checked, not marked. Write a few sentences, then compare with the example answer. Your writing is saved as you type.
Show an example answer
It includes behaviour after week 4, which the prediction system could not yet observe. Use a feature limited to the available early window.
Check: did you answer the question, use evidence or working, and avoid claiming more than the evidence supports?
Show an example answer
When the schedule was already announced and accessible before the prediction cutoff. Use the schedule version known then, not a later revision.
Check: did you answer the question, use evidence or working, and avoid claiming more than the evidence supports?