Children on the autism spectrum can find the long-term goal of matching objects difficult to master. They may have a deficit in the observational skills necessary for distinguishing whether two objects are similar, or perhaps identical. While learning to match similar or identical objects enables children to point out similarities, it also teaches them to point out differences and distinguish dissimilar items from one another. These skills can then further be translated into language development, as well as other life skills such as doing laundry or completing school assignments.

The following strategies may help your child make progress towards mastering the long-term goal of matching objects:

• Set standards using examples. Practice asking and answering the question “What two items are identical?” Be sure to show your child what two identical items are by using references. For example, show your child two pictures that are identical, such as two pictures of the same shirt or two pictures of the same animal. State to your child that they are identical objects or items and make sure to point out how they are identical. Find points of similarity between the two objects. For example, count with your child five ways in which the objects are identical. Encourage your child to ask questions about why they are identical, and take the time to point out differences if they ask if a different picture is identical. Instead of using pictures of objects, this process can also be done with the real objects, such as two of the same toy, two cups, two socks, two pencils, etc.

Identical Matching- School Supplies by Jena Holzkamp | TPT (teacherspayteachers.com)

vps-mts_1.5m-_photos.pdf (weebly.com)

Printable Free Matching Activities for Toddlers - The Measured Mom

Montessori Picture to Picture Matching, Early Literacy, Pre-Reading Activities (teacherspayteachers.com)

Matching non-identical object (generalization) by ABAFUNANDGAMES (teacherspayteachers.com)

Everyday Objects Photos by Lindsay Terrien | TPT (teacherspayteachers.com)

• Sort examples. Once your child is comfortable with the idea that two objects are identical, provide them with examples of identical objects and have them pair the identical objects together. You can use images of items, or real items, such as identical toys, items of clothing, or even plates, bowls, cutlery, or other kitchen items. Start with two pairs of objects that are different, such as two identical toys and two identical shirts. Ask your child to pair the two toys together and the two shirts together. Reward your child when they successfully pair the identical objects together. This may be in the form of verbal praise (Good job!) and / or offering a preferred item as a reward. Phase out the positive reinforcement when the skill has been sufficiently acquired. If the reinforcer for the behavior is a tangible item, such as a small snack or a token for a token board, ensure that it is provided with a great deal of verbal praise. Ideally, you want your child’s positive behaviors to be supported solely by social reinforcement. As your child becomes more comfortable with pairing identical objects together, you can make the process more challenging for them, such as by asking them to match two pairs of different shirts (i.e, 4 shirts total). Be sure to continue to reward your child when they correctly pair the identical objects together and phase out the reward as they begin to become comfortable with certain matchings. Reinstate the reward when trying a new object pairing, as necessary.
• Additional Resources:

vps-mts_1.5m-_datasheet.pdf (weebly.com)

Basic Learner Skills Part 1: Visual Performance - The Autism Helper

What age do toddlers stack, nest and match toys? | Lovevery

A lesson plan for toddlers: matching objects | Lovevery

matching-updated_10-2012-final.pdf (autismpartnership.com)

In order to help your child master the long-term goal of matching objects, you can work with your child on the short-term goals of matching identical objects (e.g., matching identical laundry items), matching similar object (e.g., sorting laundry), or organizing spaces according to category. For the short-term goal of matching identical objects, you can choose a target such as matching identical laundry items, matching socks, matching identical shirts, matching pencils, matching cups, etc.

Matching Identical Objects

• Step 1: Decide what identical objects (e.g., identical laundry items) you would like your child to match. For example, you can choose the target of matching socks while working on the short-term goal of matching identical objects. The task analysis for matching identical socks might be:

1. Gather together the socks in a pile.
2. Find points of comparison between the socks to identify which are identical:

1. First, check what size the socks are. If they are the same size, proceed to the next step. If they are not the same size, set them aside.
2. Next, check what color the socks are. If they are the same size and the same color, proceed to the next step. If they are not the same color, set them aside.
3. Finally, check what pattern is on the socks. If they are the same size, same color, and same pattern, they are identical. Repeat this process until all socks have been matched, or have been put aside to await their match.

1. Once identical socks have been identified (see above), pair together the socks that are identical. Now, the identical socks have been matched.
2. Put away matched socks where socks belong (e.g., in a drawer or closet or wherever socks are stored).
3. Put any remaining unmatched socks in a drawer or in a laundry area or elsewhere to await their match.

• Step 2: An initial / specific discriminative stimulus (SD) should be selected that will cue your child that the task will start. This SD can be a visual SD, such as two identical socks, or a verbal SD (“Time to match socks!”).
• Step 3: Collect baseline level data by providing the SD from Step 2 and allowing your child to attempt independently. The baseline level will vary according to your child and their specific abilities. Take data on which steps were accurately done independently. For example, you can count how many steps in a row (from the task analysis in Step 1) your child can complete independently. Alternatively, if your child is able to complete the entire task analysis independently, record how long it takes your child is able to complete it independently (e.g., 5 min, 10 min, 15 min, etc.).
• Step 4: To begin the trial to monitor progress towards meeting the target (i.e., the target of matching identical socks), provide the SD from Step 2 and allow your child to attempt independently. When your child is successful, provide reinforcement. If the reinforcer for the behavior is a tangible item, such as a small snack or a token for a token board, ensure that it is provided with a great deal of verbal praise. Ideally, you want your child’s positive behavior to be supported solely by social reinforcement. If the behavior was not displayed, end the trial and provide the appropriate level of prompting on the following trial. For example, employ a model prompt to show your child what to do at the beginning of the following trial (e.g., model for your child how to gather socks in a pile, then match the identical socks together and put them away, followed by putting away the remaining unmatched socks).
• Step 5: Collect data on how your child makes progress. For example, count how many steps in a row (from the task analysis in Step 1) your child can complete independently. Decide if you want to utilize forwards or backwards chaining to teach the steps that your child may struggle to complete independently. Alternatively, you can track progress by recording how long it takes your child to complete all the steps from the task analysis in Step 1. Or, alternatively, you can track progress by counting the number of successful attempts at matching identical socks during a session. 
• Step 6: Track how your child makes progress to meet the target of matching socks by comparing with either a number threshold or a percentage threshold (necessary to meet the target). For example, you can record the number of successful attempts at matching identical socks over a certain number of sessions, and compare that with the number threshold necessary to meet the target. Alternatively, you can record what percentage of times your child can complete all the steps from the task analysis in Step 1, and compare that with the percentage threshold necessary to meet the target.

Matching Similar Objects

For the short-term goal of matching similar objects, you can choose a target such as matching similar laundry items, matching similar shirts, matching similar pants, etc.

• Step 1: Decide what similar objects (e.g., similar laundry items) you would like your child to match. For example, you can choose the target of matching similar short-sleeved shirts while working on the short-term goal of matching similar laundry items. The task analysis for matching similar short-sleeved shirts might be:

1. Gather together different types of shirts in a pile (e.g., short-sleeved shirts, long-sleeved shirts, tank tops, button-up shirts, etc.).
2. Select the short-sleeved shirts from the pile.
3. Find points of comparison between the short-sleeved shirts to identify which are similar:

1. First, check what size the short-sleeved shirts are. If they are of similar size, proceed to the next step. If they are not of similar size, set them aside.
2. Next, check what color the short-sleeved shirts are. For example, you can match the shirts by type of color (i.e., light colors and dark colors). If they are of similar size and of similar type of color (e.g., light color), proceed to the next step. If they are not of similar type of color, set them aside.
3. Finally, check what type of neck the short-sleeved shirts have. If they are of similar size, of similar colors, and have similar types of necks (e.g., different types of v-necks), the short-sleeved shirts are similar. Repeat this process until all similar short-sleeved shirts have been matched together, or have been put aside to await their matches.

1. Put away all similar short-sleeved shirts where they belong (e.g., in a drawer or closet or wherever the short-sleeved t-shirts are stored).

• Step 2: An initial / specific discriminative stimulus (SD) should be selected that will cue your child that the task will start. This SD can be a visual SD, such as two similar short-sleeved shirts, or a verbal SD (“Time to match short-sleeved shirts!”).
• Step 3: Collect baseline level data by providing the SD from Step 2 and allowing your child to attempt independently. The baseline level will vary according to your child and their specific abilities. Take data on which steps were accurately done independently. For example, you can count how many steps in a row (from the task analysis in Step 1) your child can complete independently. Alternatively, if your child is able to complete the entire task analysis independently, record how long it takes your child is able to complete it independently (e.g., 5 min, 10 min, 15 min, etc.).
• Step 4: To begin the trial to monitor progress towards meeting the target (i.e., the target of matching similar short-sleeved shirts), provide the SD from Step 2 and allow your child to attempt independently. When your child is successful, provide reinforcement. If the reinforcer for the behavior is a tangible item, such as a small snack or a token for a token board, ensure that it is provided with a great deal of verbal praise. Ideally, you want your child’s positive behavior to be supported solely by social reinforcement. If the behavior was not displayed, end the trial and provide the appropriate level of prompting on the following trial. For example, employ a model prompt to show your child what to do at the beginning of the following trial (e.g., model for your child how to gather shirts in a pile, followed by matching the similar short-sleeved shirts together and putting them away).
• Step 5: Collect data on how your child makes progress. For example, count how many steps in a row (from the task analysis in Step 1) your child can complete independently. Decide if you want to utilize forwards or backwards chaining to teach the steps that your child may struggle to complete independently. Alternatively, you can track progress by recording how long it takes your child to complete all the steps from the task analysis in Step 1. Or, alternatively, you can track progress by counting the number of successful attempts at matching similar short-sleeved shirts during a session. 
• Step 6: Track how your child makes progress to meet the target of matching short-sleeved shirts by comparing with either a number threshold or a percentage threshold (necessary to meet the target). For example, you can record the number of successful attempts at matching similar shirts over a certain number of sessions, and compare that with the number threshold necessary to meet the target. Alternatively, you can record what percentage of times your child can complete all the steps from the task analysis in Step 1, and compare that with the percentage threshold necessary to meet the target.