SCANS is an abstract reasoning mnemonic used to determine a specific pattern that shapes and elements are sequenced in.
Each letter represents a potential element of the sequence, which i like to refer to as ‘pattern players’.
It is typically used in abstract reasoning exams to quickly find relationships between shape objects in order to determine what the next pattern might be, or which group a sequence belongs to.
SCANS is widely used by top-scoring students during the UCAT which is notorious for being very time-constrained. It’s definitely something you should at least try out and see if it works for you!
Here is a typically abstract reasoning set and by the end, we will figure out what the pattern is. Maybe you would like to try for yourself first?
What is SCANS?
Since the UCAT is so time-restricted, memory recall devices that allows you to quickly check an abstract reasoning image for a pattern can be extremely crucial especially if abstract reasoning isn’t your strong suit.
SCANS is no different. Each letter represents an aspect of a pattern you could be checking to determine the overall pattern of the image.
S represents Shape usually. C represents Colour. The letter A usually represents Arrangement but some also include Angle. N usually represents Numbers. The secondary S usually represents Symmetry or Size of objects.
It is important to understand what to look for with each letter of SCANS, and how to be efficient with it. We will use the original image above as our example set going forward.
Shapes are an integral part of abstract reasoning questions and will usually have a part ot play in whatever sequence you are looking at.
The tricky thing with shapes is that there are so many ways they can be arranged, it may take some time before you start to see patterns immediately.
When looking at shapes, the first thing you should be asking yourself is what shapes are present in set A, and what are present in set B?
Something that is becoming more frequently used by test writers is that both set A and B will consist of similar shapes however there may be one shape that is present in only 1 set.
There may also be relational shapes.
Relational (or conditional) shapes are shapes that are present or absent based on the presence or absence of another shape. This can get relatively complex especially when other pattern players are involved so don’t worry about this too much!
You likely won’t encounter too many of these conditional patterns.
Another thing to always take note with shapes is their internal angles and number of straight edges. You must also be aware about whether they are concave or convex shapes.
Using the example set above, we can apply what we have learnt about shapes to an actual set.
We can clearly see that there are shapes formed from straight lines in each set. There are also some arrows and little circles. Anything can be the sequence really but since we see that the only constant element are the straight lined shapes, the small circle and arrow are likely to be distractors.
Another hint that they are distractors is that they aren’t present in every box. This could be bacause they are relying on a sequence, but in this case, because there is no shape based reason for their existence, we will ignore them.
here are some observations we can see from just looking at the shapes alone.
shape based observations
- straight-edged shapes are present in every box and in both sequences. This makes it an important object to look at further.
- small circles are present in some boxes, in both sets.
- Arrow elements are present in both sets.
- No real discernable patterns between shapes, arrows and circles.
Let’s move on to see what the sequence will end up as!
Colour is a simple but often overlooked pattern element in abstract reasoning sequences. It can be pretty confusing to keep all the colour changes and their associated shapes in your head while you register patterns.
The most important thing is to keep things simple!
Ask yourself if there are any different colours to analyse in the set. If there are, which shapes have the different colours?
This is where you start pulling in knowledge from the other pattern players.
If certain shapes are associated with certain colours, does this change based on which set you are looking at?
The good thing about abstract reasoning questions are that there is a limited number of colours they can use due to the exam being in black and white.
You might begin seeing more colours based on patterns like stripes, dashed lines and dots.
It is also important to look out for the number of times a certain coloured shape occurs e.g 2-black, 1 grey, 3 white in each box. The position of 1 element might also determine the colour of another.
colour based observations for our example sequence
Our example sequence doesn’t seem to have any specific colour-based patterns.
- All shapes are black
- Colour cannot play a role in our sequence
We are doing good! So far we have covered shape and colour, but this doesn’t seem to be enough to get the full picture! We have a partial idea of the sequence and sometimes this is enough to answer the question correctly!
We know that it is definitely something to do with the big straight-lined shapes. Straight lines form angles so this might play an important role in understanding our initial sequence!
Arrangement and Angle
Working out the arrangement of objects can arguabely be the hardest part of abstract reasoning patterns.
This is because arrangements are usually the broadest category. Combined with the fact that we are also looking for angles (since they both start with the letter A), this part of SCANS can be tricky.
Some people hate combining arrangement and angle since they seem quite arbritrarily linked, however you should be reminded that SCANS is just a framework to query patterns.
To keep things simple for yourself, you should be asking some basic questions. Many things can constitute an arrangement so here are some you should think about.
- Do the shapes congregate in one corner of the box?
- Can you draw a straight line through common elements?
- Do common shapes occupy a larger portion of the box?
- Are some shapes always on the left or right, or top or bottom of other shapes?
- Are shapes curving in a clockwise or anti-clockwise manner? (more about shape than position or arrangement)
- Which direction do shapes point in relative to other shapes?
Remember that everything is linked. Arrangement is linked to shapes, and everything else so there are no hard set boundaries to look out for!
Also remember that arrangement is very similar to position so whenever you are thinking about this part of SCANS, consider the position of shapes. It might help you see from a different viewpoint.
With regards to angles, sequences are a bit easier to watch out for.
- Are there straight lines connect? If so, what angles are they making?
- How many angles are they making?
- If the shape is closed off, what are the sum of internal angles?
- Are the angles obtuse, acute, right angled?
- How many obtuse, acute, or right-angled angles are there in the set?
Arrangement observations for our example sequence
Our example sequence doesn’t seem to have any specific arrangement based sequence. It may be confusing to discern this at first since there are other elements to distract us.
- 3 lines are always joining which means at least 2 angles are formed.
- The lines never join to make a triangle which always has internal angles of 180 degrees.
- Set A angles seem to all be obtuse ie greater than 90 degrees but less than 180.
- Set B angles seem to all be acute angle ie less than 90 degrees.
Amazing! We have found a major sequence which is enough to answer most questions regarding these sets. The rule seems to hold that set A objects have obtuse angles and set B lines form acute angles.
Let’s continue with the rest of SCANS to make sure we haven’t missed anything.
Numbers and nesting
Number and counting are where people usuall start when it comes to recognising abstract patterns.
It’s the easiest to check for but often a big contributor to why you may run out of time.
It is true that many sequences have a numerical component to them and simply enumerating number of objects, sides, or colours is the right way to check, however not every questions is like this, and you might end up wasting precious time counting everything!
Things to consider when deciding whether to count:
- The objects are shapes. spirals, clocks, grids and circle based shapes are usually less likely to have counter based sequence.
- Count when the objects look similar.
- Count when right angles are involved.
- Count when other methods seems unlikely or have failed
Remember that over-counting is a real problem for test takers so try not to.
Nesting is all about looking for shapes that fall within other shapes.
Nesting is likely to involve a large main shape with a smaller shape drawn within.
This is likely to feature in type 3 questions.
Observations from set above
There doesn’t seem to be any nesting present.
When you see nesting, begin comparing sets systematically to see what the differences are. This is often quicker than finding what the sequences are separately.
Pro tip: It is usually quite helpful to compare the simplest boxes in each set against each other to make the sequence recognition that much quicker!
Size and symmetry
Finally, size and symmetry are two key checks to make on any abstract reasoning patterns.
Size is the easiest to look out for, however symmetry is a little tricker and can often seem simpler than it is.
In reality, symmetry is quite easy but silly mistakes might cause you to totally miss the right pattern.
Symmetry is all about folding shapes and having them line up properly.
Needless to say, symmetry doesn’t seem to play an integral role in any of the above sets.
A quick throwback to BBC Bitesize never hurt anyone!
SCANS is an important tool to help guide you through the process of recognising abstract sequences in a set.
Without it, you will likely struggle to keep track of the patterns you have already checked which could mean wasting valuable time.
SCANS isn’t for everyone since people sometimes like to check for other elements that aren’t explicitly mentioned in SCANS. It is however a very good starting point for developing your own mnemonics for abstract reasoning.
It is also important to mention that SCANS isn’t a fixed structure that must be done in order. SCANS is a framework to help you search for patterns which will often be a combination of any pattern players.
It is therefore nessesary to think of these headings as linked and co-dependent, instead of independent things to sequentially look for in a pattern.
Let me know what you think about SCANS in the comment or if you have any other tips that have helped you during practice!
Example Sequence Answer
The complete set was as follows.
All the boxes in Set A and B contain a shape made up of 3 line segments, so the difference in this shape must be key to both patterns.
All the angles in the 3-segment shapes are obtuse (greater than 90 degrees).
All the angles in the 3-segments shapes are acute (less than 90 degrees).
Question, where do these test shapes belong?
I’ve included some practice sets from the example set above just to make sure you have understood the SCANS method and the sequences involved in this set. Let me know what you think the answers are!
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