Study Guides

2025 Thinking Skills in OC and Selective Tests

From Question Breakdown to Key Strategies – Everything You Need for OC & Selective Tests!

Apr 04 2025

◈ Thinking Skills in OC and Selective Tests

: Structure, Style, and Complexity

From a high-level perspective, both Opportunity Class (OC) Thinking Skills and Selective High School (SHS) Thinking Skills tests are designed to measure reasoning ability in upper-primary students (OC) and high-school entry students (SHS). That said, there are several differences that can stand out in style, structure, and the level of complexity:

Category	OC	Selective
Student Target Age / Context	Typically sat by students in Year 4 seeking placement in a Year 5 Opportunity Class	Typically sat by students in Year 6 seeking entry into a Selective High School (Year 7)
Number of Questions and Time Allowed	30 questions, completed within around 30 minutes	40 questions, completed within around 40 minutes
Question Difficulty / Depth	Reasoning problems often have a more accessible reading level and smaller numbers or simpler arithmetic in multi-step questions	The same core Thinking Skills categories appear—evaluating arguments, logical analysis, multi-step numeric reasoning—but the questions can require slightly deeper or more multi-step reasoning, and reading passages or puzzle structures can be lengthier or more complex
Vocabulary / Reading Level	The passages and puzzle wordings are pitched to a younger reading level (Year 4)	The language can be more sophisticated and the contexts sometimes broader, reflecting the older students’ typical reading comprehension
Content Overlap	Despite differences in complexity, both tests assess similar broad logic and reasoning categories: ● Set relationships ● Ordering/arrangements ● Evaluating or strengthening/weakening arguments ● Multi-step numeric or code puzzles ● Identifying mistakes / confounding factors ● Interpreting partial information Overall, you’ll see the same fundamental skill areas—just calibrated to the respective ages.
Scoring Weight / Position in Overall Exam	Both are typically one section of a multi-part test. The Thinking Skills results factor into the overall selection score but usually in different weightings or scoring formulas, depending on each year’s official guidelines

▶ Key Takeaway

OC Thinking Skills is aimed at slightly younger students (mainly Year 4), tends to be briefer, and the difficulty level is somewhat lower.
Selective Thinking Skills is for Year 6, typically has more questions and a higher complexity of reading and logic.

They share the same fundamental puzzle types—logical reasoning, critical reading, problem-solving steps
—but the level of academic maturity and time frames differ.

◈ Overview of Concepts for OC and Selective Thinking Skills

Concept	Related Main Topics	Explanation
Identifying Similarity	● Visual & Spatial Reasoning – Folding nets into cubes or other solids – Determining different views (top, side, bottom) – Finding matching / non-matching shapes or patterns	These questions primarily test shape transformations, vantage-point identification, or comparing patterns. They may ask, “Which net folds into this solid?” or “Which arrangement is consistent with the partial diagram?”
Finding Procedures	● Multi-step Arithmetic & Code Puzzles – Converting units (recipes, currency, time, etc.) -Summing or distributing constraints – Simple cipher/letter logic (shift codes, string-pattern constraints) ● Ranking / Scheduling (if it involves repeated numeric steps)	These typically require step-by-step problem-solving or calculation. Some puzzle examples: – Figuring out maximum cupcakes from limited ingredients – Decrypting a code via repeated letter shifting – Combining multiple constraints (like bus passes on certain days, cost comparisons, or multi-currency conversions)
Evaluating Evidence	● Argument Strengthening & Weakening – Confounding vs. supporting data – Overlooked factors for or against a proposition	You see a short claim (e.g., “Running daily improves chess.”) and pick which piece of new info most strongly supports or undermines that claim.
Evaluating Reasoning	● Two Characters’ Statements – “A says X, B says Y,” deciding if each conclusion is valid ● Confounding Factors (sometimes integrated here)	A pair of individuals interpret the same fact differently, so you must judge whether one, both, or neither is correct. Typically uses the same condition-based logic as “Evaluating evidence,” but focuses on checking the logic of each speaker.
Identifying Mistakes	● Incorrect Assumptions / Overlooked Criteria ● Double Counting / Confounding ● Flawed Logic (e.g., “I’ve never seen it, so it must not exist.”)	Here, someone draws a faulty conclusion from the given statements, and you find which statement best reveals the flaw. It can be an assumption about correlation, ignoring data, or unproven generalization.
Logical Analysis	● Conditional Reasoning – If–then, chain-of-conditions ● Set & Membership Logic – “All X who do Y also do Z,” or “No X can do Y.” ● Truth–Lies Puzzle ● Ordering / Arrangement (positions, ranks) ● Partial Info (who qualifies, which scenario is possible)	Encompasses the broad realm of syllogisms, chain-of-conditions, set membership logic, truth-lies statements, or rank/positional puzzles. Usually the question is “Which arrangement must/can be true?” or “Which scenario can’t happen?”

◈ Overview of Concepts for OC and Selective Thinking Skills by Concept

Concept Area	Sub-concept	Description
1.Logic & Reasoning Concepts	A. Conditional Reasoning	● If–then statements: e.g. “If A happens, then B must happen, unless C.” ● Contrapositive thinking: e.g. “If you need at least 20 hours for a chance, then having <20 hours means no chance.” ● Chain of conditions: combining multiple “If A, then B; If B, then C” statements.
	B. Set & Membership Logic	● “All X are Y,” “No X are Y,” “Some X are Y.” ● Venn-like mental pictures: you might see wording like “Everyone who plays soccer also does karate,” or “No cat-lovers like dogs.” ● You deduce which overlaps or separations must or cannot exist.
	C. Ordering & Arrangement	● Rank ordering (1st, 2nd, 3rd, etc.): “X finished after Y but before Z.” ● Seat or position arrangements: “A is to the left of B; B is left of C… who’s in the middle?” ● Scheduling or calendar-based logic: “Which days are feasible for each activity?”
	D. Evaluating Arguments	● Strengthening or weakening an argument: “Which new fact best supports / undermines this claim?” ● Overlooked/Confounding factors: typical question style: “Which sentence shows the error in the reasoning?”
	E. Identifying Mistakes in Reasoning	● Incorrect assumptions: e.g., “I haven’t seen it happen, so it can’t be true.” ● Over-generalization: “If it’s true for one instance, it must be true for all.” ● Double counting or missing information that changes the conclusion.
	F. Truth–Lies or Partial-Information Puzzles	● Exactly one statement is true, or exactly two statements are false, etc. ● Deduce which statement(s) must hold under the constraints.
	G. Visual & Spatial Reasoning	● Shape transformations (folding nets into cubes, or vantage points from top/side views). ● Jigsaw or tiling: “Which piece completes the shape so no edges conflict?” ● Diagram interpretation: overhead maps, building layers, or partial 3D structures.
	H. Multi-step Arithmetic & Code Puzzles	● Converting units (e.g., $ / cost, recipes, time intervals). ● Summing constraints (like “if you have X ingredients, how many cupcakes can be made?”). ● Simple ciphers, letter positions, string pattern constraints (no triple repetition, etc.).
2.Mathematical Foundations		While there’s no advanced “Year 7” or “Year 8” algebra in these tests, you do need solid command of: ● Basic operations (add, subtract, multiply, divide). ● Ratios or unit conversions (if the puzzle uses them). ● Reading tables/graphs: bar charts, line charts, easy pie charts. ● Perimeter/time tasks, or small geometry details (though “Thinking Skills” typically revolve more around logic than raw geometry).
3.Critical “Soft Skills” / Strategies		Regardless of the specific “theory,” success often hinges on: 1. Careful reading: Many errors come from misreading a single condition. 2. Systematic notation: For set and chain logic, rewriting “If A then B” in your own words or marking each clue on a mini-diagram. 3. Eliminating impossibilities: Process of elimination is a staple for multi-option logic puzzles. 4. Time management: Especially for older tests (Selective), you have slightly more questions and deeper complexity

▶ Summary

Both OC and Selective “Thinking Skills” test a common set of logical, verbal, and numerical puzzle concepts:

Basic logic structures (if–then, set membership),
Puzzle-solving with arrangement, schedule, numeric constraints,
Evaluating or critiquing arguments (including confounding factors, ignoring data),
Visual or 2D/3D shape interpretatio

OC exam will keep the reading simpler and the numeric steps fewer, while Selective might push these same concepts with greater complexity or length. In either case, the essential theories are these fundamental logic, set relationships, and multi-step reasoning skills.