PECS Phase 3 – Picture Discrimination

PECS phase 3

The Picture Exchange Communication System® / PECS® is how we communicate with my non-verbal son. He started using PECS when he was 2 years old, he is now 5 and still using it. I’m not going to lie we have good days and bad days with PECS. However having the ability to functionally communicate his needs and desires is so important.

If you don’t know what the Picture Exchange Communication System is then check out my post on phase one.  If you have mastered phase one (exchange) and phase two (distance and persistence) then you are ready to start phase 3 – picture discrimination.

PECS phase 3

PECS Phase 3

The aim of the third phrase is for the child to be able to select the appropriate picture from several choices. I still remember the look on my son’s face when he had that light bulb moment. He realised the cards had pictures that linked to the objects. In phase 1 & 2 the focus has been on the exchange of one card, at this point the child may not have looked at the picture. Even if they have seen the picture they may not have made the connection. This is why picture discrimination needs to be taught.

Thankfully my son got picture discrimination really quickly. Many autistic children have great visual skills which is why PECS works so well. My son was already a big puzzle fan and we would use matching games in our TEACCH work. He was already used to looking at visuals

Below I will go through the basic steps to teaching phase 3. However I really recommend taking the PECS UK training course as it is so detailed.

Picture Discrimination

Phase one has taught the child to exchange the picture card. Now the child needs to learn how to select that card. To start with this is done with two cards, one will be a preferred item and the other non-preferred.

PECS phase 3

Having an item the child wants (preferred) vs an item the child doesn’t want (non-preferred) will teach the consequence of choice. At first this was a little hard as items I chose as non-preferred, like a paperclip, were requested. This was because it was new and something he hadn’t played with before. Initially it is really important for there to be a clear definition between wanting one item and not wanting the other.

Non Preferred vs Preferred Items

PECS Phase 3 preferred and non preferred items

I definitely made a few mistakes when selecting my preferred and non preferred items if this happens just change the choices. Have several options to start with. This way if items aren’t desirable enough or a non-preferred turns out to be of interest you can move on quickly.

When we started with PECS I really struggled to understand what items my son was motivated by. Over time I got much better at this but here is a list of my motivating items which may be helpful. Food is often a good place to start, chocolate buttons were always a winner for my son.

The iPad was also a huge motivator so we used an app that had small puzzles (4 pieces). He would get the ipad to do one puzzle, then we took it back and he would have to request again for the next puzzle. Seems a bit harsh but he took to it really well and it gave us lot’s of practice time. As he became more confident requesting he would get more time. Now he asks and he might get half an hour or even an hour if mummy wants a shower.

Finding non-preferred items is key to learning to discriminate. I found using food items my son dislikes (most vegetables) worked well against cake or chocolate. Mundane household items also work well such as buttons, socks, cutlery, empty cups and plates.

How to implement PECS phase 3

As your child has already mastered exchanging PECS cards you should be able to implement phase 3 on your own.

Once you have selected your two items hold them in one hand as you will need the other hand to accept the card. You need to have both cards available in front of the child. At first we did it at a table as it was easier for us.

PECS phase 3 chocolate v spoon

Straightaway my boy grabbed a card without looking at it. The first two phases had taught him he needed to exchange a card to get an item so that is what he did. This is where you need to give the child the corresponding item to the card they have given you. If you have an upset child because they have got the spoon instead of the chocolate then that’s great, they have a preferred item they were expecting to get. The more they get it wrong at first then usually the quicker they will catch on that the pictures correspond to an item.

You are just teaching the art of picture discrimination here so as soon as a picture is selected you can praise the child and give the item even if a full exchange doesn’t happen. Once you have got the hang of discrimination then you can go back to ensuring a full exchange etc.

It was after I handed my son a sock instead of the sweets he wanted that he looked down and saw the sweet picture he hadn’t selected. This is when he looked as me and I saw he got it. He realised the picture on the card was important to this exchange. After that he only made mistakes when he was excited and not paying attention to cards.

Error Correction

When a child makes a mistake and selects the wrong item you can use the PECS 4-step error correction procedure.

  1. Model – show the child the picture they want to choose (you can do this by tapping it).
  2. Practice – do a practice exchange with the correct card.
  3. Switch – distract the child, this can be moving the book or asking them to sit down or clap hands (as long as it is something they understand).
  4. Repeat – start again and this time when the correct card is selected they get the item. If they make the wrong selection again repeat the error correction.

Personally it took me a little while to master the error correction procedure. It might be worth practising this or having a prompt for yourself.Some children will get this really quickly and for others it will take time. If the child is struggling there are other options. For example having the preferred item cards bigger than the non-preferred or more faded to help prompt which card to choose.

A good variety of choices and lots of practice will always help improve picture discrimination. Don’t use the same non preferred item all the time, the child will just learn to avoid that card not to actually choose the right card.

Choosing between preferred items

Once the child can discriminate easily between a non-preferred and a preferred item you can move to two preferred items. Some autistic children can struggle with choice so initially we still only want to offer two items.

pecs phase 3

Now that there is a choice of two preferred items we need to make sure the child is choosing the correct card. To do this we put the items on a tray, as you can see in the picture a shoe box lid works just fine too. Now when the child exchanges the card you offer the tray and say ‘take it’. If the child goes for the item they have exchanged the card for great. If the child goes for the other item then you need to block the exchange and do the error correction procedure. The reason you say ‘take it’ is so you are not naming the item which could lead them to take that item.

Once the child is confident choosing between two items correctly then increase to three items.

PECS Phase 3

While practising make sure you move the cards around so that they don’t know where it is every time and need to actually look at the pictures. Once three pictures is mastered go onto 5 items, this works well with snacks.

PECS phase 3

After they can easily discriminate between 5 you can the introduce a range of choices. Such as our TV Choice board.

TV Choice board
TV Choice board

Using a communication book is great as the child then has to look through the pages and you can store more cards.

Picture Exchange Communication Book, PECS

If you want to know more about making PECS cards or what to include in a communication book check out my post on making and storing PECS cards. Once the child has mastered selecting the correct picture from a communication book you can make sure the skills from phase 1 & 2 are still being used. When happy they have all three phases mastered move onto phase 4 – Sentence Structure.

I hope this has been helpful, I really do recommend the PECS UK course, I found it very helpful. If you would like more information about autism and resources to support your child at home then you can sign up to my monthly mailing list. You will also receive a free guide to the top autism therapies for young children.

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  1. 1st February 2019 / 9:09 pm

    This is so helpful as so many people just assume PECS is just a child’s handed you a card, or a visual schedule. Thank you for taking the time to break each stage down with clear visuals. It’s very helpful and I am sure many will refer to this I wrote and over again.

  2. Anonymous
    1st February 2019 / 10:04 pm

    Really useful! This is something we might look to exploring in the future.

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