Verify Sorva/du Boulay and add the notional-machine grounding to computational-thinking LOs

[dbosk]

Context

Grounding the computational-thinking learning objectives in the
phenomenography / variation-theory literature. The revised LO2 lists an
algorithm's huvudbeståndsdelar as sequence/execution-order, state,
variables, selection (branching), iteration (repetition) and functions. A
literature search backed the decomposition with three personally-verified
sources, now cited in the \ltnotes and recorded with provenance in
modules/computational-thinking/slides/ltnotes.bib:

• Böhm & Jacopini 1966 (structured-program theorem)
• Pea 1986 (parallelism bug / superbug)
• Qian & Lehman 2017 (CS1 conceptual-knowledge constituents)

Observation

The strongest additional grounding — that sequence/execution-order and
the "notional machine" (how the computer executes) are critical aspects
novices must discern — comes from Sorva (Visual Program Simulation,
PhD thesis, Aalto 2012; "Notional Machines and Introductory Programming
Education", ACM TOCE 13(2), 2013) and du Boulay 1986 (the notional
machine). These were surfaced by the search but not cited, because
their full texts could not all be fetched and personally verified in that
round (the scholar pdf quote download of the Aalto thesis failed). An
unverified reference is not committed.

The sokprotokoll.tex appendix ("Sökt men ej använt") already records
this gap honestly.

Why it matters

The notional machine is, per the reviewed literature, the single
most-cited answer to "what must a novice learn to understand programs," and
it is the substrate that makes sequence and state intelligible. It is the
strongest candidate for an explicit addition to the LO/overview, and would
let us cite Sorva/du Boulay for the execution-order aspect directly rather
than leaning only on Pea + Qian & Lehman.

Evidence

• modules/computational-thinking/slides/sokprotokoll.tex, paragraph "Sökt
  men ej använt".
• Subagent literature report (this session): Sorva 2012 p.110 "A static
  perspective limited to program text needs to be developed into a dynamic
  one that takes execution-time behavior into account"; p.67–69 notional
  machine definition (quoting du Boulay).
• Sorva's thesis is open access: http://lib.tkk.fi/Diss/2012/isbn9789526046266/
  (aaltodoc). Reading the OA PhD thesis directly is the way around the
  failed scholar pdf quote download.

Suggested follow-up

1. Read Sorva's OA PhD thesis (aaltodoc) directly; verify the
   static→dynamic-execution and notional-machine quotes personally.
2. Add sorva2012 (and sorva2013; and duboulay1986 if its full text can
   be verified) to ltnotes.bib with FOUND-VIA / QUOTE / VERIFIED
   provenance blocks.
3. Cite them in the aspects \ltnote and add the episode to
   sokprotokoll.tex.
4. Consider adding "the notional machine / how the computer executes" as
   an explicit aspect in LO2 and the overview.