CogAT Kindergarten common mistakes
CogAT Kindergarten · Understand the traps and how to avoid them.
When asked which picture 'does not belong' in a picture-group, the child picks the picture they personally dislike or find scary (e.g., the spider) instead of the one that differs in category or attribute from the rest.
At age 5-6, children sort by personal preference and emotional salience before they can reliably sort by a shared rule. A scary or highly interesting image captures attention and overrides the categorical comparison the item requires.
What to do instead
Practise 'find the rule' games at home: lay out four picture cards, three sharing a category (animals) and one different (car), and ask the child to say what the three have in common before choosing the odd one. Require the child to name the shared feature out loud ('these all fly') before pointing. Do 3-5 rounds, alternating categories (food, vehicles, animals, clothes) so the child learns to search for the shared attribute rather than react to the picture.
On verbal analogy items read aloud ('Bird is to nest as bee is to ___'), the child answers with a word that merely sounds related or rhymes, or repeats a word from the prompt, rather than completing the relationship.
The analogy is delivered orally, so the child must hold the first pair in working memory, infer the relation, and then search for a matching relation. Kindergarteners often latch onto the last word heard ('bee') or a sound association because the relational comparison is the harder step.
What to do instead
Use a physical two-step routine: 'First pair: bird goes with nest - why? It's where it lives. Second pair: bee goes with...?' Have the child restate the relation in a short sentence before answering. Practise with concrete pairs (dog/kennel, fish/water, farmer/farm) and always ask 'why does that go together?' after the answer so the child rehearses the relation, not just the word.
The child gives up or says 'I don't know' when a verbal item uses an uncommon word, instead of using the sentence context or the answer choices to narrow the meaning.
Vocabulary breadth varies widely at this age, and a single unknown noun can feel like a total block. Young children have not yet learned that the surrounding words and the options themselves carry usable clues.
What to do instead
Teach a 'guess from the sentence' habit: read a short sentence with a made-up or unfamiliar word ('The zorb was so heavy the wagon tipped') and ask what the word probably means, praising any reasonable inference. Then practise with the answer choices visible: 'Two of these are animals and one is a tool - which word do you not know? Let's see which group it must fit.' Build the expectation that an unknown word is a puzzle, not a stop sign.
On oral classification items ('Which one does not belong: apple, banana, carrot, grape?'), the child picks the item that is least familiar or least liked rather than the one from a different category, and cannot explain the choice.
Category knowledge is still forming and is strongly tied to home experience. A child who has never eaten a carrot may treat it as the odd one for the wrong reason, or may classify by colour or shape instead of by kind.
What to do instead
Play 'name the group' daily with real objects or pictures: put out three fruits and one vegetable and ask the child to name the group first ('these are all fruits'), then find the one that does not fit. Extend to mixed attributes (all red vs all round) and ask the child to justify the choice in one sentence. Rotate through food, animals, furniture, and clothing so categories are broad, not just the child's favourites.
On quantitative comparison items, the child judges 'more' by how far the objects spread out or how tall the stack looks rather than by counting or one-to-one matching, so a spread-out row of four is called more than a tight row of six.
This is classic conservation/centration: before roughly age 7, children are dominated by one perceptual dimension (length or height) and ignore number. It is a developmental stage, not inattention, so telling the child to 'look carefully' does not help.
What to do instead
Practise one-to-one matching with counters: line up two rows, then pair each item in row A with one in row B to see which has leftovers. Then deliberately spread one row out and ask again, having the child re-pair to check. Do the same with equal-volume liquids in tall/narrow vs short/wide glasses to break the 'taller means more' habit. Always let the child verify by counting or matching rather than by looking.
The child counts '1, 2, 3, 4, 5' while touching objects but skips one, double-counts another, or keeps reciting past the last object, then reports the wrong total.
Accurate counting requires coordinating three skills at once - the verbal sequence, pointing to one object per number, and knowing that the last number said is the total (cardinality). Five-year-olds often have the sequence memorised but not yet synchronised with pointing.
What to do instead
Slow the count down with a physical routine: move each object away as it is counted ('one - move it'), so skipped or double-counted items are visible. Use small sets (3-6) and ask 'so how many are there?' after the last number to reinforce cardinality. Then count scattered arrangements, not just rows, and have the child recount to self-check. Keep sessions to 5 minutes and stop while it is still fun.
On number-series items (2, 4, 6, __), the child guesses a number that 'looks right' or continues the spoken rhythm without working out the step, and cannot explain how the series changes.
Pattern-finding requires holding the sequence, comparing consecutive terms, and inferring a rule - a multi-step operation that kindergarteners often replace with a global 'feel' for the numbers. Skip-counting by 2s or 5s may be memorised as a chant without the underlying step.
What to do instead
Make the step visible with objects: build two rows of counters, add the same amount each time, and say the step aloud ('plus two, plus two'). Cover the next term and ask 'what will come next - and how do you know?' Practise series with a constant step using blocks, then with a number line the child can point to. Always require the 'how do you know' explanation so the rule, not the guess, is what gets practised.
On figure-analogy or matrix items (a shape changes in one way, so a second shape must change the same way), the child copies the sample picture exactly or picks the option that looks most like the first figure, instead of applying the transformation.
The child must separate the rule (e.g., 'gets bigger', 'rotates', 'loses a dot') from the specific shapes and then transfer it. At this age, visual similarity is far more compelling than abstract transformation, so the child matches appearance rather than relation.
What to do instead
Practise 'same change' puzzles with physical shapes: show a small circle becoming a big circle, then ask what happens to a small square. Have the child narrate the change ('it got bigger') before choosing. Use one transformation at a time (size, then colour, then rotation), then combine two. Ask the child to point to the rule in the first pair and say it aloud before looking at the answer options.
On paper-folding or paper-punching items, the child answers from what the folded shape looks like now rather than mentally unfolding it, so holes are placed only where they appear in the folded picture.
Mental unfolding requires imagining a mirror reflection across the fold line and tracking that a single punch produces two holes. This spatial transformation is demanding at age five, and the folded diagram is visually dominant.
What to do instead
Do real folding with thin paper and a hole punch: fold, punch, then unfold and count the holes together, marking the fold line. Repeat with two folds and predict before unfolding. Then move to drawn items and have the child trace the fold line with a finger and 'mirror' the hole across it. Start with one fold and one punch before combining folds.
On spatial-orientation items (which piece completes the square, which shape is the same but turned), the child chooses an option that is a mirror image or a different size, treating 'looks similar' as 'matches'.
Discriminating a rotation from a reflection, and matching exact size and shape, requires fine visual discrimination that is still developing. Mirror images feel identical to a young child because the overall outline matches.
What to do instead
Use a physical template and cut-out shapes: give the child a shape and ask them to slide, then flip, then turn it to fit a gap, naming each move. For 'same but turned' items, have the child rotate the actual cut-out over the printed option to check the fit. Include deliberate mirror-image distractors and ask 'is this the same shape or a flipped twin?' so the distinction becomes explicit.